diff options
| author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 | 
|---|---|---|
| committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 | 
| commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
| tree | 65ca85f13617aee1dce474596800950f266a456c /libdecnumber | |
| download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip  | |
Diffstat (limited to 'libdecnumber')
| -rw-r--r-- | libdecnumber/decContext.c | 433 | ||||
| -rw-r--r-- | libdecnumber/decNumber.c | 8195 | ||||
| -rw-r--r-- | libdecnumber/dpd/decimal128.c | 564 | ||||
| -rw-r--r-- | libdecnumber/dpd/decimal32.c | 489 | ||||
| -rw-r--r-- | libdecnumber/dpd/decimal64.c | 850 | 
5 files changed, 10531 insertions, 0 deletions
diff --git a/libdecnumber/decContext.c b/libdecnumber/decContext.c new file mode 100644 index 00000000..8b6ae21b --- /dev/null +++ b/libdecnumber/decContext.c @@ -0,0 +1,433 @@ +/* Decimal context module for the decNumber C Library. +   Copyright (C) 2005, 2007 Free Software Foundation, Inc. +   Contributed by IBM Corporation.  Author Mike Cowlishaw. + +   This file is part of GCC. + +   GCC is free software; you can redistribute it and/or modify it under +   the terms of the GNU General Public License as published by the Free +   Software Foundation; either version 2, or (at your option) any later +   version. + +   In addition to the permissions in the GNU General Public License, +   the Free Software Foundation gives you unlimited permission to link +   the compiled version of this file into combinations with other +   programs, and to distribute those combinations without any +   restriction coming from the use of this file.  (The General Public +   License restrictions do apply in other respects; for example, they +   cover modification of the file, and distribution when not linked +   into a combine executable.) + +   GCC is distributed in the hope that it will be useful, but WITHOUT ANY +   WARRANTY; without even the implied warranty of MERCHANTABILITY or +   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License +   for more details. + +   You should have received a copy of the GNU General Public License +   along with GCC; see the file COPYING.  If not, write to the Free +   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +   02110-1301, USA.  */ + +/* ------------------------------------------------------------------ */ +/* Decimal Context module					      */ +/* ------------------------------------------------------------------ */ +/* This module comprises the routines for handling arithmetic	      */ +/* context structures.						      */ +/* ------------------------------------------------------------------ */ + +#include <string.h>	      /* for strcmp */ +#include <stdio.h>	      /* for printf if DECCHECK */ +#include "libdecnumber/dconfig.h" +#include "libdecnumber/decContext.h" +#include "libdecnumber/decNumberLocal.h" + +#if DECCHECK +/* compile-time endian tester [assumes sizeof(Int)>1] */ +static	const  Int mfcone=1;		     /* constant 1 */ +static	const  Flag *mfctop=(Flag *)&mfcone; /* -> top byte */ +#define LITEND *mfctop		   /* named flag; 1=little-endian */ +#endif + +/* ------------------------------------------------------------------ */ +/* round-for-reround digits					      */ +/* ------------------------------------------------------------------ */ +const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */ + +/* ------------------------------------------------------------------ */ +/* Powers of ten (powers[n]==10**n, 0<=n<=9)			      */ +/* ------------------------------------------------------------------ */ +const uLong DECPOWERS[19] = {1, 10, 100, 1000, 10000, 100000, 1000000, +  10000000, 100000000, 1000000000, 10000000000ULL, 100000000000ULL, +  1000000000000ULL, 10000000000000ULL, 100000000000000ULL, 1000000000000000ULL, +  10000000000000000ULL, 100000000000000000ULL, 1000000000000000000ULL, }; + +/* ------------------------------------------------------------------ */ +/* decContextClearStatus -- clear bits in current status	      */ +/*								      */ +/*  context is the context structure to be queried		      */ +/*  mask indicates the bits to be cleared (the status bit that	      */ +/*    corresponds to each 1 bit in the mask is cleared)		      */ +/*  returns context						      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decContext *decContextClearStatus(decContext *context, uInt mask) { +  context->status&=~mask; +  return context; +  } /* decContextClearStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextDefault -- initialize a context structure		      */ +/*								      */ +/*  context is the structure to be initialized			      */ +/*  kind selects the required set of default values, one of:	      */ +/*	DEC_INIT_BASE	    -- select ANSI X3-274 defaults	      */ +/*	DEC_INIT_DECIMAL32  -- select IEEE 754r defaults, 32-bit      */ +/*	DEC_INIT_DECIMAL64  -- select IEEE 754r defaults, 64-bit      */ +/*	DEC_INIT_DECIMAL128 -- select IEEE 754r defaults, 128-bit     */ +/*	For any other value a valid context is returned, but with     */ +/*	Invalid_operation set in the status field.		      */ +/*  returns a context structure with the appropriate initial values.  */ +/* ------------------------------------------------------------------ */ +decContext * decContextDefault(decContext *context, Int kind) { +  /* set defaults... */ +  context->digits=9;			     /* 9 digits */ +  context->emax=DEC_MAX_EMAX;		     /* 9-digit exponents */ +  context->emin=DEC_MIN_EMIN;		     /* .. balanced */ +  context->round=DEC_ROUND_HALF_UP;	     /* 0.5 rises */ +  context->traps=DEC_Errors;		     /* all but informational */ +  context->status=0;			     /* cleared */ +  context->clamp=0;			     /* no clamping */ +  #if DECSUBSET +  context->extended=0;			     /* cleared */ +  #endif +  switch (kind) { +    case DEC_INIT_BASE: +      /* [use defaults] */ +      break; +    case DEC_INIT_DECIMAL32: +      context->digits=7;		     /* digits */ +      context->emax=96;			     /* Emax */ +      context->emin=-95;		     /* Emin */ +      context->round=DEC_ROUND_HALF_EVEN;    /* 0.5 to nearest even */ +      context->traps=0;			     /* no traps set */ +      context->clamp=1;			     /* clamp exponents */ +      #if DECSUBSET +      context->extended=1;		     /* set */ +      #endif +      break; +    case DEC_INIT_DECIMAL64: +      context->digits=16;		     /* digits */ +      context->emax=384;		     /* Emax */ +      context->emin=-383;		     /* Emin */ +      context->round=DEC_ROUND_HALF_EVEN;    /* 0.5 to nearest even */ +      context->traps=0;			     /* no traps set */ +      context->clamp=1;			     /* clamp exponents */ +      #if DECSUBSET +      context->extended=1;		     /* set */ +      #endif +      break; +    case DEC_INIT_DECIMAL128: +      context->digits=34;		     /* digits */ +      context->emax=6144;		     /* Emax */ +      context->emin=-6143;		     /* Emin */ +      context->round=DEC_ROUND_HALF_EVEN;    /* 0.5 to nearest even */ +      context->traps=0;			     /* no traps set */ +      context->clamp=1;			     /* clamp exponents */ +      #if DECSUBSET +      context->extended=1;		     /* set */ +      #endif +      break; + +    default:				     /* invalid Kind */ +      /* use defaults, and .. */ +      decContextSetStatus(context, DEC_Invalid_operation); /* trap */ +    } + +  #if DECCHECK +  if (LITEND!=DECLITEND) { +    const char *adj; +    if (LITEND) adj="little"; +	   else adj="big"; +    printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n", +	   DECLITEND, adj); +    } +  #endif +  return context;} /* decContextDefault */ + +/* ------------------------------------------------------------------ */ +/* decContextGetRounding -- return current rounding mode	      */ +/*								      */ +/*  context is the context structure to be queried		      */ +/*  returns the rounding mode					      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +enum rounding decContextGetRounding(decContext *context) { +  return context->round; +  } /* decContextGetRounding */ + +/* ------------------------------------------------------------------ */ +/* decContextGetStatus -- return current status			      */ +/*								      */ +/*  context is the context structure to be queried		      */ +/*  returns status						      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uInt decContextGetStatus(decContext *context) { +  return context->status; +  } /* decContextGetStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextRestoreStatus -- restore bits in current status	      */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  newstatus is the source for the bits to be restored		      */ +/*  mask indicates the bits to be restored (the status bit that	      */ +/*    corresponds to each 1 bit in the mask is set to the value of    */ +/*    the correspnding bit in newstatus)			      */ +/*  returns context						      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decContext *decContextRestoreStatus(decContext *context, +				    uInt newstatus, uInt mask) { +  context->status&=~mask;		/* clear the selected bits */ +  context->status|=(mask&newstatus);	/* or in the new bits */ +  return context; +  } /* decContextRestoreStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextSaveStatus -- save bits in current status		      */ +/*								      */ +/*  context is the context structure to be queried		      */ +/*  mask indicates the bits to be saved (the status bits that	      */ +/*    correspond to each 1 bit in the mask are saved)		      */ +/*  returns the AND of the mask and the current status		      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uInt decContextSaveStatus(decContext *context, uInt mask) { +  return context->status&mask; +  } /* decContextSaveStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextSetRounding -- set current rounding mode		      */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  newround is the value which will replace the current mode	      */ +/*  returns context						      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decContext *decContextSetRounding(decContext *context, +				  enum rounding newround) { +  context->round=newround; +  return context; +  } /* decContextSetRounding */ + +/* ------------------------------------------------------------------ */ +/* decContextSetStatus -- set status and raise trap if appropriate    */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  status  is the DEC_ exception code				      */ +/*  returns the context structure				      */ +/*								      */ +/* Control may never return from this routine, if there is a signal   */ +/* handler and it takes a long jump.				      */ +/* ------------------------------------------------------------------ */ +decContext * decContextSetStatus(decContext *context, uInt status) { +  context->status|=status; +  if (status & context->traps) raise(SIGFPE); +  return context;} /* decContextSetStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextSetStatusFromString -- set status from a string + trap   */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  string is a string exactly equal to one that might be returned    */ +/*	      by decContextStatusToString			      */ +/*								      */ +/*  The status bit corresponding to the string is set, and a trap     */ +/*  is raised if appropriate.					      */ +/*								      */ +/*  returns the context structure, unless the string is equal to      */ +/*    DEC_Condition_MU or is not recognized.  In these cases NULL is  */ +/*    returned.							      */ +/* ------------------------------------------------------------------ */ +decContext * decContextSetStatusFromString(decContext *context, +					   const char *string) { +  if (strcmp(string, DEC_Condition_CS)==0) +    return decContextSetStatus(context, DEC_Conversion_syntax); +  if (strcmp(string, DEC_Condition_DZ)==0) +    return decContextSetStatus(context, DEC_Division_by_zero); +  if (strcmp(string, DEC_Condition_DI)==0) +    return decContextSetStatus(context, DEC_Division_impossible); +  if (strcmp(string, DEC_Condition_DU)==0) +    return decContextSetStatus(context, DEC_Division_undefined); +  if (strcmp(string, DEC_Condition_IE)==0) +    return decContextSetStatus(context, DEC_Inexact); +  if (strcmp(string, DEC_Condition_IS)==0) +    return decContextSetStatus(context, DEC_Insufficient_storage); +  if (strcmp(string, DEC_Condition_IC)==0) +    return decContextSetStatus(context, DEC_Invalid_context); +  if (strcmp(string, DEC_Condition_IO)==0) +    return decContextSetStatus(context, DEC_Invalid_operation); +  #if DECSUBSET +  if (strcmp(string, DEC_Condition_LD)==0) +    return decContextSetStatus(context, DEC_Lost_digits); +  #endif +  if (strcmp(string, DEC_Condition_OV)==0) +    return decContextSetStatus(context, DEC_Overflow); +  if (strcmp(string, DEC_Condition_PA)==0) +    return decContextSetStatus(context, DEC_Clamped); +  if (strcmp(string, DEC_Condition_RO)==0) +    return decContextSetStatus(context, DEC_Rounded); +  if (strcmp(string, DEC_Condition_SU)==0) +    return decContextSetStatus(context, DEC_Subnormal); +  if (strcmp(string, DEC_Condition_UN)==0) +    return decContextSetStatus(context, DEC_Underflow); +  if (strcmp(string, DEC_Condition_ZE)==0) +    return context; +  return NULL;	/* Multiple status, or unknown */ +  } /* decContextSetStatusFromString */ + +/* ------------------------------------------------------------------ */ +/* decContextSetStatusFromStringQuiet -- set status from a string     */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  string is a string exactly equal to one that might be returned    */ +/*	      by decContextStatusToString			      */ +/*								      */ +/*  The status bit corresponding to the string is set; no trap is     */ +/*  raised.							      */ +/*								      */ +/*  returns the context structure, unless the string is equal to      */ +/*    DEC_Condition_MU or is not recognized.  In these cases NULL is  */ +/*    returned.							      */ +/* ------------------------------------------------------------------ */ +decContext * decContextSetStatusFromStringQuiet(decContext *context, +						const char *string) { +  if (strcmp(string, DEC_Condition_CS)==0) +    return decContextSetStatusQuiet(context, DEC_Conversion_syntax); +  if (strcmp(string, DEC_Condition_DZ)==0) +    return decContextSetStatusQuiet(context, DEC_Division_by_zero); +  if (strcmp(string, DEC_Condition_DI)==0) +    return decContextSetStatusQuiet(context, DEC_Division_impossible); +  if (strcmp(string, DEC_Condition_DU)==0) +    return decContextSetStatusQuiet(context, DEC_Division_undefined); +  if (strcmp(string, DEC_Condition_IE)==0) +    return decContextSetStatusQuiet(context, DEC_Inexact); +  if (strcmp(string, DEC_Condition_IS)==0) +    return decContextSetStatusQuiet(context, DEC_Insufficient_storage); +  if (strcmp(string, DEC_Condition_IC)==0) +    return decContextSetStatusQuiet(context, DEC_Invalid_context); +  if (strcmp(string, DEC_Condition_IO)==0) +    return decContextSetStatusQuiet(context, DEC_Invalid_operation); +  #if DECSUBSET +  if (strcmp(string, DEC_Condition_LD)==0) +    return decContextSetStatusQuiet(context, DEC_Lost_digits); +  #endif +  if (strcmp(string, DEC_Condition_OV)==0) +    return decContextSetStatusQuiet(context, DEC_Overflow); +  if (strcmp(string, DEC_Condition_PA)==0) +    return decContextSetStatusQuiet(context, DEC_Clamped); +  if (strcmp(string, DEC_Condition_RO)==0) +    return decContextSetStatusQuiet(context, DEC_Rounded); +  if (strcmp(string, DEC_Condition_SU)==0) +    return decContextSetStatusQuiet(context, DEC_Subnormal); +  if (strcmp(string, DEC_Condition_UN)==0) +    return decContextSetStatusQuiet(context, DEC_Underflow); +  if (strcmp(string, DEC_Condition_ZE)==0) +    return context; +  return NULL;	/* Multiple status, or unknown */ +  } /* decContextSetStatusFromStringQuiet */ + +/* ------------------------------------------------------------------ */ +/* decContextSetStatusQuiet -- set status without trap		      */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  status  is the DEC_ exception code				      */ +/*  returns the context structure				      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decContext * decContextSetStatusQuiet(decContext *context, uInt status) { +  context->status|=status; +  return context;} /* decContextSetStatusQuiet */ + +/* ------------------------------------------------------------------ */ +/* decContextStatusToString -- convert status flags to a string	      */ +/*								      */ +/*  context is a context with valid status field		      */ +/*								      */ +/*  returns a constant string describing the condition.	 If multiple  */ +/*    (or no) flags are set, a generic constant message is returned.  */ +/* ------------------------------------------------------------------ */ +const char *decContextStatusToString(const decContext *context) { +  Int status=context->status; + +  /* test the five IEEE first, as some of the others are ambiguous when */ +  /* DECEXTFLAG=0 */ +  if (status==DEC_Invalid_operation    ) return DEC_Condition_IO; +  if (status==DEC_Division_by_zero     ) return DEC_Condition_DZ; +  if (status==DEC_Overflow	       ) return DEC_Condition_OV; +  if (status==DEC_Underflow	       ) return DEC_Condition_UN; +  if (status==DEC_Inexact	       ) return DEC_Condition_IE; + +  if (status==DEC_Division_impossible  ) return DEC_Condition_DI; +  if (status==DEC_Division_undefined   ) return DEC_Condition_DU; +  if (status==DEC_Rounded	       ) return DEC_Condition_RO; +  if (status==DEC_Clamped	       ) return DEC_Condition_PA; +  if (status==DEC_Subnormal	       ) return DEC_Condition_SU; +  if (status==DEC_Conversion_syntax    ) return DEC_Condition_CS; +  if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; +  if (status==DEC_Invalid_context      ) return DEC_Condition_IC; +  #if DECSUBSET +  if (status==DEC_Lost_digits	       ) return DEC_Condition_LD; +  #endif +  if (status==0			       ) return DEC_Condition_ZE; +  return DEC_Condition_MU;  /* Multiple errors */ +  } /* decContextStatusToString */ + +/* ------------------------------------------------------------------ */ +/* decContextTestSavedStatus -- test bits in saved status	      */ +/*								      */ +/*  oldstatus is the status word to be tested			      */ +/*  mask indicates the bits to be tested (the oldstatus bits that     */ +/*    correspond to each 1 bit in the mask are tested)		      */ +/*  returns 1 if any of the tested bits are 1, or 0 otherwise	      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uInt decContextTestSavedStatus(uInt oldstatus, uInt mask) { +  return (oldstatus&mask)!=0; +  } /* decContextTestSavedStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextTestStatus -- test bits in current status		      */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  mask indicates the bits to be tested (the status bits that	      */ +/*    correspond to each 1 bit in the mask are tested)		      */ +/*  returns 1 if any of the tested bits are 1, or 0 otherwise	      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uInt decContextTestStatus(decContext *context, uInt mask) { +  return (context->status&mask)!=0; +  } /* decContextTestStatus */ + +/* ------------------------------------------------------------------ */ +/* decContextZeroStatus -- clear all status bits		      */ +/*								      */ +/*  context is the context structure to be updated		      */ +/*  returns context						      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decContext *decContextZeroStatus(decContext *context) { +  context->status=0; +  return context; +  } /* decContextZeroStatus */ diff --git a/libdecnumber/decNumber.c b/libdecnumber/decNumber.c new file mode 100644 index 00000000..58211e7a --- /dev/null +++ b/libdecnumber/decNumber.c @@ -0,0 +1,8195 @@ +/* Decimal number arithmetic module for the decNumber C Library. +   Copyright (C) 2005, 2007 Free Software Foundation, Inc. +   Contributed by IBM Corporation.  Author Mike Cowlishaw. + +   This file is part of GCC. + +   GCC is free software; you can redistribute it and/or modify it under +   the terms of the GNU General Public License as published by the Free +   Software Foundation; either version 2, or (at your option) any later +   version. + +   In addition to the permissions in the GNU General Public License, +   the Free Software Foundation gives you unlimited permission to link +   the compiled version of this file into combinations with other +   programs, and to distribute those combinations without any +   restriction coming from the use of this file.  (The General Public +   License restrictions do apply in other respects; for example, they +   cover modification of the file, and distribution when not linked +   into a combine executable.) + +   GCC is distributed in the hope that it will be useful, but WITHOUT ANY +   WARRANTY; without even the implied warranty of MERCHANTABILITY or +   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License +   for more details. + +   You should have received a copy of the GNU General Public License +   along with GCC; see the file COPYING.  If not, write to the Free +   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +   02110-1301, USA.  */ + +/* ------------------------------------------------------------------ */ +/* Decimal Number arithmetic module				      */ +/* ------------------------------------------------------------------ */ +/* This module comprises the routines for General Decimal Arithmetic  */ +/* as defined in the specification which may be found on the	      */ +/* http://www2.hursley.ibm.com/decimal web pages.  It implements both */ +/* the full ('extended') arithmetic and the simpler ('subset')	      */ +/* arithmetic.							      */ +/*								      */ +/* Usage notes:							      */ +/*								      */ +/* 1. This code is ANSI C89 except:				      */ +/*								      */ +/*       If DECDPUN>4 or DECUSE64=1, the C99 64-bit int64_t and	      */ +/*	 uint64_t types may be used.  To avoid these, set DECUSE64=0  */ +/*	 and DECDPUN<=4 (see documentation).			      */ +/*								      */ +/* 2. The decNumber format which this library uses is optimized for   */ +/*    efficient processing of relatively short numbers; in particular */ +/*    it allows the use of fixed sized structures and minimizes copy  */ +/*    and move operations.  It does, however, support arbitrary	      */ +/*    precision (up to 999,999,999 digits) and arbitrary exponent     */ +/*    range (Emax in the range 0 through 999,999,999 and Emin in the  */ +/*    range -999,999,999 through 0).  Mathematical functions (for     */ +/*    example decNumberExp) as identified below are restricted more   */ +/*    tightly: digits, emax, and -emin in the context must be <=      */ +/*    DEC_MAX_MATH (999999), and their operand(s) must be within      */ +/*    these bounds.						      */ +/*								      */ +/* 3. Logical functions are further restricted; their operands must   */ +/*    be finite, positive, have an exponent of zero, and all digits   */ +/*    must be either 0 or 1.  The result will only contain digits     */ +/*    which are 0 or 1 (and will have exponent=0 and a sign of 0).    */ +/*								      */ +/* 4. Operands to operator functions are never modified unless they   */ +/*    are also specified to be the result number (which is always     */ +/*    permitted).  Other than that case, operands must not overlap.   */ +/*								      */ +/* 5. Error handling: the type of the error is ORed into the status   */ +/*    flags in the current context (decContext structure).  The	      */ +/*    SIGFPE signal is then raised if the corresponding trap-enabler  */ +/*    flag in the decContext is set (is 1).			      */ +/*								      */ +/*    It is the responsibility of the caller to clear the status      */ +/*    flags as required.					      */ +/*								      */ +/*    The result of any routine which returns a number will always    */ +/*    be a valid number (which may be a special value, such as an     */ +/*    Infinity or NaN).						      */ +/*								      */ +/* 6. The decNumber format is not an exchangeable concrete	      */ +/*    representation as it comprises fields which may be machine-     */ +/*    dependent (packed or unpacked, or special length, for example). */ +/*    Canonical conversions to and from strings are provided; other   */ +/*    conversions are available in separate modules.		      */ +/*								      */ +/* 7. Normally, input operands are assumed to be valid.	 Set DECCHECK */ +/*    to 1 for extended operand checking (including NULL operands).   */ +/*    Results are undefined if a badly-formed structure (or a NULL    */ +/*    pointer to a structure) is provided, though with DECCHECK	      */ +/*    enabled the operator routines are protected against exceptions. */ +/*    (Except if the result pointer is NULL, which is unrecoverable.) */ +/*								      */ +/*    However, the routines will never cause exceptions if they are   */ +/*    given well-formed operands, even if the value of the operands   */ +/*    is inappropriate for the operation and DECCHECK is not set.     */ +/*    (Except for SIGFPE, as and where documented.)		      */ +/*								      */ +/* 8. Subset arithmetic is available only if DECSUBSET is set to 1.   */ +/* ------------------------------------------------------------------ */ +/* Implementation notes for maintenance of this module:		      */ +/*								      */ +/* 1. Storage leak protection:	Routines which use malloc are not     */ +/*    permitted to use return for fastpath or error exits (i.e.,      */ +/*    they follow strict structured programming conventions).	      */ +/*    Instead they have a do{}while(0); construct surrounding the     */ +/*    code which is protected -- break may be used to exit this.      */ +/*    Other routines can safely use the return statement inline.      */ +/*								      */ +/*    Storage leak accounting can be enabled using DECALLOC.	      */ +/*								      */ +/* 2. All loops use the for(;;) construct.  Any do construct does     */ +/*    not loop; it is for allocation protection as just described.    */ +/*								      */ +/* 3. Setting status in the context must always be the very last      */ +/*    action in a routine, as non-0 status may raise a trap and hence */ +/*    the call to set status may not return (if the handler uses long */ +/*    jump).  Therefore all cleanup must be done first.	 In general,  */ +/*    to achieve this status is accumulated and is only applied just  */ +/*    before return by calling decContextSetStatus (via decStatus).   */ +/*								      */ +/*    Routines which allocate storage cannot, in general, use the     */ +/*    'top level' routines which could cause a non-returning	      */ +/*    transfer of control.  The decXxxxOp routines are safe (do not   */ +/*    call decStatus even if traps are set in the context) and should */ +/*    be used instead (they are also a little faster).		      */ +/*								      */ +/* 4. Exponent checking is minimized by allowing the exponent to      */ +/*    grow outside its limits during calculations, provided that      */ +/*    the decFinalize function is called later.	 Multiplication and   */ +/*    division, and intermediate calculations in exponentiation,      */ +/*    require more careful checks because of the risk of 31-bit	      */ +/*    overflow (the most negative valid exponent is -1999999997, for  */ +/*    a 999999999-digit number with adjusted exponent of -999999999). */ +/*								      */ +/* 5. Rounding is deferred until finalization of results, with any    */ +/*    'off to the right' data being represented as a single digit     */ +/*    residue (in the range -1 through 9).  This avoids any double-   */ +/*    rounding when more than one shortening takes place (for	      */ +/*    example, when a result is subnormal).			      */ +/*								      */ +/* 6. The digits count is allowed to rise to a multiple of DECDPUN    */ +/*    during many operations, so whole Units are handled and exact    */ +/*    accounting of digits is not needed.  The correct digits value   */ +/*    is found by decGetDigits, which accounts for leading zeros.     */ +/*    This must be called before any rounding if the number of digits */ +/*    is not known exactly.					      */ +/*								      */ +/* 7. The multiply-by-reciprocal 'trick' is used for partitioning     */ +/*    numbers up to four digits, using appropriate constants.  This   */ +/*    is not useful for longer numbers because overflow of 32 bits    */ +/*    would lead to 4 multiplies, which is almost as expensive as     */ +/*    a divide (unless a floating-point or 64-bit multiply is	      */ +/*    assumed to be available).					      */ +/*								      */ +/* 8. Unusual abbreviations that may be used in the commentary:	      */ +/*	lhs -- left hand side (operand, of an operation)	      */ +/*	lsd -- least significant digit (of coefficient)		      */ +/*	lsu -- least significant Unit (of coefficient)		      */ +/*	msd -- most significant digit (of coefficient)		      */ +/*	msi -- most significant item (in an array)		      */ +/*	msu -- most significant Unit (of coefficient)		      */ +/*	rhs -- right hand side (operand, of an operation)	      */ +/*	+ve -- positive						      */ +/*	-ve -- negative						      */ +/*	**  -- raise to the power				      */ +/* ------------------------------------------------------------------ */ + +#include <stdlib.h>		   /* for malloc, free, etc. */ +#include <stdio.h>		   /* for printf [if needed] */ +#include <string.h>		   /* for strcpy */ +#include <ctype.h>		   /* for lower */ +#include "libdecnumber/dconfig.h" +#include "libdecnumber/decNumber.h" +#include "libdecnumber/decNumberLocal.h" + +/* Constants */ +/* Public lookup table used by the D2U macro */ +const uByte d2utable[DECMAXD2U+1]=D2UTABLE; + +#define DECVERB	    1		   /* set to 1 for verbose DECCHECK */ +#define powers	    DECPOWERS	   /* old internal name */ + +/* Local constants */ +#define DIVIDE	    0x80	   /* Divide operators */ +#define REMAINDER   0x40	   /* .. */ +#define DIVIDEINT   0x20	   /* .. */ +#define REMNEAR	    0x10	   /* .. */ +#define COMPARE	    0x01	   /* Compare operators */ +#define COMPMAX	    0x02	   /* .. */ +#define COMPMIN	    0x03	   /* .. */ +#define COMPTOTAL   0x04	   /* .. */ +#define COMPNAN	    0x05	   /* .. [NaN processing] */ +#define COMPSIG	    0x06	   /* .. [signaling COMPARE] */ +#define COMPMAXMAG  0x07	   /* .. */ +#define COMPMINMAG  0x08	   /* .. */ + +#define DEC_sNaN     0x40000000	   /* local status: sNaN signal */ +#define BADINT	(Int)0x80000000	   /* most-negative Int; error indicator */ +/* Next two indicate an integer >= 10**6, and its parity (bottom bit) */ +#define BIGEVEN (Int)0x80000002 +#define BIGODD	(Int)0x80000003 + +static Unit uarrone[1]={1};   /* Unit array of 1, used for incrementing */ + +/* Granularity-dependent code */ +#if DECDPUN<=4 +  #define eInt	Int	      /* extended integer */ +  #define ueInt uInt	      /* unsigned extended integer */ +  /* Constant multipliers for divide-by-power-of five using reciprocal */ +  /* multiply, after removing powers of 2 by shifting, and final shift */ +  /* of 17 [we only need up to **4] */ +  static const uInt multies[]={131073, 26215, 5243, 1049, 210}; +  /* QUOT10 -- macro to return the quotient of unit u divided by 10**n */ +  #define QUOT10(u, n) ((((uInt)(u)>>(n))*multies[n])>>17) +#else +  /* For DECDPUN>4 non-ANSI-89 64-bit types are needed. */ +  #if !DECUSE64 +    #error decNumber.c: DECUSE64 must be 1 when DECDPUN>4 +  #endif +  #define eInt	Long	      /* extended integer */ +  #define ueInt uLong	      /* unsigned extended integer */ +#endif + +/* Local routines */ +static decNumber * decAddOp(decNumber *, const decNumber *, const decNumber *, +			      decContext *, uByte, uInt *); +static Flag	   decBiStr(const char *, const char *, const char *); +static uInt	   decCheckMath(const decNumber *, decContext *, uInt *); +static void	   decApplyRound(decNumber *, decContext *, Int, uInt *); +static Int	   decCompare(const decNumber *lhs, const decNumber *rhs, Flag); +static decNumber * decCompareOp(decNumber *, const decNumber *, +			      const decNumber *, decContext *, +			      Flag, uInt *); +static void	   decCopyFit(decNumber *, const decNumber *, decContext *, +			      Int *, uInt *); +static decNumber * decDecap(decNumber *, Int); +static decNumber * decDivideOp(decNumber *, const decNumber *, +			      const decNumber *, decContext *, Flag, uInt *); +static decNumber * decExpOp(decNumber *, const decNumber *, +			      decContext *, uInt *); +static void	   decFinalize(decNumber *, decContext *, Int *, uInt *); +static Int	   decGetDigits(Unit *, Int); +static Int	   decGetInt(const decNumber *); +static decNumber * decLnOp(decNumber *, const decNumber *, +			      decContext *, uInt *); +static decNumber * decMultiplyOp(decNumber *, const decNumber *, +			      const decNumber *, decContext *, +			      uInt *); +static decNumber * decNaNs(decNumber *, const decNumber *, +			      const decNumber *, decContext *, uInt *); +static decNumber * decQuantizeOp(decNumber *, const decNumber *, +			      const decNumber *, decContext *, Flag, +			      uInt *); +static void	   decReverse(Unit *, Unit *); +static void	   decSetCoeff(decNumber *, decContext *, const Unit *, +			      Int, Int *, uInt *); +static void	   decSetMaxValue(decNumber *, decContext *); +static void	   decSetOverflow(decNumber *, decContext *, uInt *); +static void	   decSetSubnormal(decNumber *, decContext *, Int *, uInt *); +static Int	   decShiftToLeast(Unit *, Int, Int); +static Int	   decShiftToMost(Unit *, Int, Int); +static void	   decStatus(decNumber *, uInt, decContext *); +static void	   decToString(const decNumber *, char[], Flag); +static decNumber * decTrim(decNumber *, decContext *, Flag, Int *); +static Int	   decUnitAddSub(const Unit *, Int, const Unit *, Int, Int, +			      Unit *, Int); +static Int	   decUnitCompare(const Unit *, Int, const Unit *, Int, Int); + +#if !DECSUBSET +/* decFinish == decFinalize when no subset arithmetic needed */ +#define decFinish(a,b,c,d) decFinalize(a,b,c,d) +#else +static void	   decFinish(decNumber *, decContext *, Int *, uInt *); +static decNumber * decRoundOperand(const decNumber *, decContext *, uInt *); +#endif + +/* Local macros */ +/* masked special-values bits */ +#define SPECIALARG  (rhs->bits & DECSPECIAL) +#define SPECIALARGS ((lhs->bits | rhs->bits) & DECSPECIAL) + +/* Diagnostic macros, etc. */ +#if DECALLOC +/* Handle malloc/free accounting.  If enabled, our accountable routines */ +/* are used; otherwise the code just goes straight to the system malloc */ +/* and free routines. */ +#define malloc(a) decMalloc(a) +#define free(a) decFree(a) +#define DECFENCE 0x5a		   /* corruption detector */ +/* 'Our' malloc and free: */ +static void *decMalloc(size_t); +static void  decFree(void *); +uInt decAllocBytes=0;		   /* count of bytes allocated */ +/* Note that DECALLOC code only checks for storage buffer overflow. */ +/* To check for memory leaks, the decAllocBytes variable must be */ +/* checked to be 0 at appropriate times (e.g., after the test */ +/* harness completes a set of tests).  This checking may be unreliable */ +/* if the testing is done in a multi-thread environment. */ +#endif + +#if DECCHECK +/* Optional checking routines.	Enabling these means that decNumber */ +/* and decContext operands to operator routines are checked for */ +/* correctness.	 This roughly doubles the execution time of the */ +/* fastest routines (and adds 600+ bytes), so should not normally be */ +/* used in 'production'. */ +/* decCheckInexact is used to check that inexact results have a full */ +/* complement of digits (where appropriate -- this is not the case */ +/* for Quantize, for example) */ +#define DECUNRESU ((decNumber *)(void *)0xffffffff) +#define DECUNUSED ((const decNumber *)(void *)0xffffffff) +#define DECUNCONT ((decContext *)(void *)(0xffffffff)) +static Flag decCheckOperands(decNumber *, const decNumber *, +			     const decNumber *, decContext *); +static Flag decCheckNumber(const decNumber *); +static void decCheckInexact(const decNumber *, decContext *); +#endif + +#if DECTRACE || DECCHECK +/* Optional trace/debugging routines (may or may not be used) */ +void decNumberShow(const decNumber *);	/* displays the components of a number */ +static void decDumpAr(char, const Unit *, Int); +#endif + +/* ================================================================== */ +/* Conversions							      */ +/* ================================================================== */ + +/* ------------------------------------------------------------------ */ +/* from-int32 -- conversion from Int or uInt			      */ +/*								      */ +/*  dn is the decNumber to receive the integer			      */ +/*  in or uin is the integer to be converted			      */ +/*  returns dn							      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberFromInt32(decNumber *dn, Int in) { +  uInt unsig; +  if (in>=0) unsig=in; +   else {				/* negative (possibly BADINT) */ +    if (in==BADINT) unsig=(uInt)1073741824*2; /* special case */ +     else unsig=-in;			/* invert */ +    } +  /* in is now positive */ +  decNumberFromUInt32(dn, unsig); +  if (in<0) dn->bits=DECNEG;		/* sign needed */ +  return dn; +  } /* decNumberFromInt32 */ + +decNumber * decNumberFromUInt32(decNumber *dn, uInt uin) { +  Unit *up;				/* work pointer */ +  decNumberZero(dn);			/* clean */ +  if (uin==0) return dn;		/* [or decGetDigits bad call] */ +  for (up=dn->lsu; uin>0; up++) { +    *up=(Unit)(uin%(DECDPUNMAX+1)); +    uin=uin/(DECDPUNMAX+1); +    } +  dn->digits=decGetDigits(dn->lsu, up-dn->lsu); +  return dn; +  } /* decNumberFromUInt32 */ + +/* ------------------------------------------------------------------ */ +/* to-int32 -- conversion to Int or uInt			      */ +/*								      */ +/*  dn is the decNumber to convert				      */ +/*  set is the context for reporting errors			      */ +/*  returns the converted decNumber, or 0 if Invalid is set	      */ +/*								      */ +/* Invalid is set if the decNumber does not have exponent==0 or if    */ +/* it is a NaN, Infinite, or out-of-range.			      */ +/* ------------------------------------------------------------------ */ +Int decNumberToInt32(const decNumber *dn, decContext *set) { +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, dn, set)) return 0; +  #endif + +  /* special or too many digits, or bad exponent */ +  if (dn->bits&DECSPECIAL || dn->digits>10 || dn->exponent!=0) ; /* bad */ +   else { /* is a finite integer with 10 or fewer digits */ +    Int d;			   /* work */ +    const Unit *up;		   /* .. */ +    uInt hi=0, lo;		   /* .. */ +    up=dn->lsu;			   /* -> lsu */ +    lo=*up;			   /* get 1 to 9 digits */ +    #if DECDPUN>1		   /* split to higher */ +      hi=lo/10; +      lo=lo%10; +    #endif +    up++; +    /* collect remaining Units, if any, into hi */ +    for (d=DECDPUN; d<dn->digits; up++, d+=DECDPUN) hi+=*up*powers[d-1]; +    /* now low has the lsd, hi the remainder */ +    if (hi>214748364 || (hi==214748364 && lo>7)) { /* out of range? */ +      /* most-negative is a reprieve */ +      if (dn->bits&DECNEG && hi==214748364 && lo==8) return 0x80000000; +      /* bad -- drop through */ +      } +     else { /* in-range always */ +      Int i=X10(hi)+lo; +      if (dn->bits&DECNEG) return -i; +      return i; +      } +    } /* integer */ +  decContextSetStatus(set, DEC_Invalid_operation); /* [may not return] */ +  return 0; +  } /* decNumberToInt32 */ + +uInt decNumberToUInt32(const decNumber *dn, decContext *set) { +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, dn, set)) return 0; +  #endif +  /* special or too many digits, or bad exponent, or negative (<0) */ +  if (dn->bits&DECSPECIAL || dn->digits>10 || dn->exponent!=0 +    || (dn->bits&DECNEG && !ISZERO(dn)));		    /* bad */ +   else { /* is a finite integer with 10 or fewer digits */ +    Int d;			   /* work */ +    const Unit *up;		   /* .. */ +    uInt hi=0, lo;		   /* .. */ +    up=dn->lsu;			   /* -> lsu */ +    lo=*up;			   /* get 1 to 9 digits */ +    #if DECDPUN>1		   /* split to higher */ +      hi=lo/10; +      lo=lo%10; +    #endif +    up++; +    /* collect remaining Units, if any, into hi */ +    for (d=DECDPUN; d<dn->digits; up++, d+=DECDPUN) hi+=*up*powers[d-1]; + +    /* now low has the lsd, hi the remainder */ +    if (hi>429496729 || (hi==429496729 && lo>5)) ; /* no reprieve possible */ +     else return X10(hi)+lo; +    } /* integer */ +  decContextSetStatus(set, DEC_Invalid_operation); /* [may not return] */ +  return 0; +  } /* decNumberToUInt32 */ + +decNumber *decNumberFromInt64(decNumber *dn, int64_t in) +{ +    uint64_t unsig = in; +    if (in < 0) { +        unsig = -unsig; +    } + +    decNumberFromUInt64(dn, unsig); +    if (in < 0) { +        dn->bits = DECNEG;        /* sign needed */ +    } +    return dn; +} /* decNumberFromInt64 */ + +decNumber *decNumberFromUInt64(decNumber *dn, uint64_t uin) +{ +    Unit *up;                             /* work pointer */ +    decNumberZero(dn);                    /* clean */ +    if (uin == 0) { +        return dn;                /* [or decGetDigits bad call] */ +    } +    for (up = dn->lsu; uin > 0; up++) { +        *up = (Unit)(uin % (DECDPUNMAX + 1)); +        uin = uin / (DECDPUNMAX + 1); +    } +    dn->digits = decGetDigits(dn->lsu, up-dn->lsu); +    return dn; +} /* decNumberFromUInt64 */ + +/* ------------------------------------------------------------------ */ +/* to-int64 -- conversion to int64                                    */ +/*                                                                    */ +/*  dn is the decNumber to convert.  dn is assumed to have been       */ +/*    rounded to a floating point integer value.                      */ +/*  set is the context for reporting errors                           */ +/*  returns the converted decNumber, or 0 if Invalid is set           */ +/*                                                                    */ +/* Invalid is set if the decNumber is a NaN, Infinite or is out of    */ +/* range for a signed 64 bit integer.                                 */ +/* ------------------------------------------------------------------ */ + +int64_t decNumberIntegralToInt64(const decNumber *dn, decContext *set) +{ +    if (decNumberIsSpecial(dn) || (dn->exponent < 0) || +       (dn->digits + dn->exponent > 19)) { +        goto Invalid; +    } else { +        int64_t d;        /* work */ +        const Unit *up;   /* .. */ +        uint64_t hi = 0; +        up = dn->lsu;     /* -> lsu */ + +        for (d = 1; d <= dn->digits; up++, d += DECDPUN) { +            uint64_t prev = hi; +            hi += *up * powers[d-1]; +            if ((hi < prev) || (hi > INT64_MAX)) { +                goto Invalid; +            } +        } + +        uint64_t prev = hi; +        hi *= (uint64_t)powers[dn->exponent]; +        if ((hi < prev) || (hi > INT64_MAX)) { +            goto Invalid; +        } +        return (decNumberIsNegative(dn)) ? -((int64_t)hi) : (int64_t)hi; +    } + +Invalid: +    decContextSetStatus(set, DEC_Invalid_operation); +    return 0; +} /* decNumberIntegralToInt64 */ + + +/* ------------------------------------------------------------------ */ +/* to-scientific-string -- conversion to numeric string		      */ +/* to-engineering-string -- conversion to numeric string	      */ +/*								      */ +/*   decNumberToString(dn, string);				      */ +/*   decNumberToEngString(dn, string);				      */ +/*								      */ +/*  dn is the decNumber to convert				      */ +/*  string is the string where the result will be laid out	      */ +/*								      */ +/*  string must be at least dn->digits+14 characters long	      */ +/*								      */ +/*  No error is possible, and no status can be set.		      */ +/* ------------------------------------------------------------------ */ +char * decNumberToString(const decNumber *dn, char *string){ +  decToString(dn, string, 0); +  return string; +  } /* DecNumberToString */ + +char * decNumberToEngString(const decNumber *dn, char *string){ +  decToString(dn, string, 1); +  return string; +  } /* DecNumberToEngString */ + +/* ------------------------------------------------------------------ */ +/* to-number -- conversion from numeric string			      */ +/*								      */ +/* decNumberFromString -- convert string to decNumber		      */ +/*   dn	       -- the number structure to fill			      */ +/*   chars[]   -- the string to convert ('\0' terminated)	      */ +/*   set       -- the context used for processing any error,	      */ +/*		  determining the maximum precision available	      */ +/*		  (set.digits), determining the maximum and minimum   */ +/*		  exponent (set.emax and set.emin), determining if    */ +/*		  extended values are allowed, and checking the	      */ +/*		  rounding mode if overflow occurs or rounding is     */ +/*		  needed.					      */ +/*								      */ +/* The length of the coefficient and the size of the exponent are     */ +/* checked by this routine, so the correct error (Underflow or	      */ +/* Overflow) can be reported or rounding applied, as necessary.	      */ +/*								      */ +/* If bad syntax is detected, the result will be a quiet NaN.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberFromString(decNumber *dn, const char chars[], +				decContext *set) { +  Int	exponent=0;		   /* working exponent [assume 0] */ +  uByte bits=0;			   /* working flags [assume +ve] */ +  Unit	*res;			   /* where result will be built */ +  Unit	resbuff[SD2U(DECBUFFER+9)];/* local buffer in case need temporary */ +				   /* [+9 allows for ln() constants] */ +  Unit	*allocres=NULL;		   /* -> allocated result, iff allocated */ +  Int	d=0;			   /* count of digits found in decimal part */ +  const char *dotchar=NULL;	   /* where dot was found */ +  const char *cfirst=chars;	   /* -> first character of decimal part */ +  const char *last=NULL;	   /* -> last digit of decimal part */ +  const char *c;		   /* work */ +  Unit	*up;			   /* .. */ +  #if DECDPUN>1 +  Int	cut, out;		   /* .. */ +  #endif +  Int	residue;		   /* rounding residue */ +  uInt	status=0;		   /* error code */ + +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, DECUNUSED, set)) +    return decNumberZero(dn); +  #endif + +  do {				   /* status & malloc protection */ +    for (c=chars;; c++) {	   /* -> input character */ +      if (*c>='0' && *c<='9') {	   /* test for Arabic digit */ +	last=c; +	d++;			   /* count of real digits */ +	continue;		   /* still in decimal part */ +	} +      if (*c=='.' && dotchar==NULL) { /* first '.' */ +	dotchar=c;		   /* record offset into decimal part */ +	if (c==cfirst) cfirst++;   /* first digit must follow */ +	continue;} +      if (c==chars) {		   /* first in string... */ +	if (*c=='-') {		   /* valid - sign */ +	  cfirst++; +	  bits=DECNEG; +	  continue;} +	if (*c=='+') {		   /* valid + sign */ +	  cfirst++; +	  continue;} +	} +      /* *c is not a digit, or a valid +, -, or '.' */ +      break; +      } /* c */ + +    if (last==NULL) {		   /* no digits yet */ +      status=DEC_Conversion_syntax;/* assume the worst */ +      if (*c=='\0') break;	   /* and no more to come... */ +      #if DECSUBSET +      /* if subset then infinities and NaNs are not allowed */ +      if (!set->extended) break;   /* hopeless */ +      #endif +      /* Infinities and NaNs are possible, here */ +      if (dotchar!=NULL) break;	   /* .. unless had a dot */ +      decNumberZero(dn);	   /* be optimistic */ +      if (decBiStr(c, "infinity", "INFINITY") +       || decBiStr(c, "inf", "INF")) { +	dn->bits=bits | DECINF; +	status=0;		   /* is OK */ +	break; /* all done */ +	} +      /* a NaN expected */ +      /* 2003.09.10 NaNs are now permitted to have a sign */ +      dn->bits=bits | DECNAN;	   /* assume simple NaN */ +      if (*c=='s' || *c=='S') {	   /* looks like an sNaN */ +	c++; +	dn->bits=bits | DECSNAN; +	} +      if (*c!='n' && *c!='N') break;	/* check caseless "NaN" */ +      c++; +      if (*c!='a' && *c!='A') break;	/* .. */ +      c++; +      if (*c!='n' && *c!='N') break;	/* .. */ +      c++; +      /* now either nothing, or nnnn payload, expected */ +      /* -> start of integer and skip leading 0s [including plain 0] */ +      for (cfirst=c; *cfirst=='0';) cfirst++; +      if (*cfirst=='\0') {	   /* "NaN" or "sNaN", maybe with all 0s */ +	status=0;		   /* it's good */ +	break;			   /* .. */ +	} +      /* something other than 0s; setup last and d as usual [no dots] */ +      for (c=cfirst;; c++, d++) { +	if (*c<'0' || *c>'9') break; /* test for Arabic digit */ +	last=c; +	} +      if (*c!='\0') break;	   /* not all digits */ +      if (d>set->digits-1) { +	/* [NB: payload in a decNumber can be full length unless */ +	/* clamped, in which case can only be digits-1] */ +	if (set->clamp) break; +	if (d>set->digits) break; +	} /* too many digits? */ +      /* good; drop through to convert the integer to coefficient */ +      status=0;			   /* syntax is OK */ +      bits=dn->bits;		   /* for copy-back */ +      } /* last==NULL */ + +     else if (*c!='\0') {	   /* more to process... */ +      /* had some digits; exponent is only valid sequence now */ +      Flag nege;		   /* 1=negative exponent */ +      const char *firstexp;	   /* -> first significant exponent digit */ +      status=DEC_Conversion_syntax;/* assume the worst */ +      if (*c!='e' && *c!='E') break; +      /* Found 'e' or 'E' -- now process explicit exponent */ +      /* 1998.07.11: sign no longer required */ +      nege=0; +      c++;			   /* to (possible) sign */ +      if (*c=='-') {nege=1; c++;} +       else if (*c=='+') c++; +      if (*c=='\0') break; + +      for (; *c=='0' && *(c+1)!='\0';) c++;  /* strip insignificant zeros */ +      firstexp=c;			     /* save exponent digit place */ +      for (; ;c++) { +	if (*c<'0' || *c>'9') break;	     /* not a digit */ +	exponent=X10(exponent)+(Int)*c-(Int)'0'; +	} /* c */ +      /* if not now on a '\0', *c must not be a digit */ +      if (*c!='\0') break; + +      /* (this next test must be after the syntax checks) */ +      /* if it was too long the exponent may have wrapped, so check */ +      /* carefully and set it to a certain overflow if wrap possible */ +      if (c>=firstexp+9+1) { +	if (c>firstexp+9+1 || *firstexp>'1') exponent=DECNUMMAXE*2; +	/* [up to 1999999999 is OK, for example 1E-1000000998] */ +	} +      if (nege) exponent=-exponent;	/* was negative */ +      status=0;				/* is OK */ +      } /* stuff after digits */ + +    /* Here when whole string has been inspected; syntax is good */ +    /* cfirst->first digit (never dot), last->last digit (ditto) */ + +    /* strip leading zeros/dot [leave final 0 if all 0's] */ +    if (*cfirst=='0') {			/* [cfirst has stepped over .] */ +      for (c=cfirst; c<last; c++, cfirst++) { +	if (*c=='.') continue;		/* ignore dots */ +	if (*c!='0') break;		/* non-zero found */ +	d--;				/* 0 stripped */ +	} /* c */ +      #if DECSUBSET +      /* make a rapid exit for easy zeros if !extended */ +      if (*cfirst=='0' && !set->extended) { +	decNumberZero(dn);		/* clean result */ +	break;				/* [could be return] */ +	} +      #endif +      } /* at least one leading 0 */ + +    /* Handle decimal point... */ +    if (dotchar!=NULL && dotchar<last)	/* non-trailing '.' found? */ +      exponent-=(last-dotchar);		/* adjust exponent */ +    /* [we can now ignore the .] */ + +    /* OK, the digits string is good.  Assemble in the decNumber, or in */ +    /* a temporary units array if rounding is needed */ +    if (d<=set->digits) res=dn->lsu;	/* fits into supplied decNumber */ +     else {				/* rounding needed */ +      Int needbytes=D2U(d)*sizeof(Unit);/* bytes needed */ +      res=resbuff;			/* assume use local buffer */ +      if (needbytes>(Int)sizeof(resbuff)) { /* too big for local */ +	allocres=(Unit *)malloc(needbytes); +	if (allocres==NULL) {status|=DEC_Insufficient_storage; break;} +	res=allocres; +	} +      } +    /* res now -> number lsu, buffer, or allocated storage for Unit array */ + +    /* Place the coefficient into the selected Unit array */ +    /* [this is often 70% of the cost of this function when DECDPUN>1] */ +    #if DECDPUN>1 +    out=0;			   /* accumulator */ +    up=res+D2U(d)-1;		   /* -> msu */ +    cut=d-(up-res)*DECDPUN;	   /* digits in top unit */ +    for (c=cfirst;; c++) {	   /* along the digits */ +      if (*c=='.') continue;	   /* ignore '.' [don't decrement cut] */ +      out=X10(out)+(Int)*c-(Int)'0'; +      if (c==last) break;	   /* done [never get to trailing '.'] */ +      cut--; +      if (cut>0) continue;	   /* more for this unit */ +      *up=(Unit)out;		   /* write unit */ +      up--;			   /* prepare for unit below.. */ +      cut=DECDPUN;		   /* .. */ +      out=0;			   /* .. */ +      } /* c */ +    *up=(Unit)out;		   /* write lsu */ + +    #else +    /* DECDPUN==1 */ +    up=res;			   /* -> lsu */ +    for (c=last; c>=cfirst; c--) { /* over each character, from least */ +      if (*c=='.') continue;	   /* ignore . [don't step up] */ +      *up=(Unit)((Int)*c-(Int)'0'); +      up++; +      } /* c */ +    #endif + +    dn->bits=bits; +    dn->exponent=exponent; +    dn->digits=d; + +    /* if not in number (too long) shorten into the number */ +    if (d>set->digits) { +      residue=0; +      decSetCoeff(dn, set, res, d, &residue, &status); +      /* always check for overflow or subnormal and round as needed */ +      decFinalize(dn, set, &residue, &status); +      } +     else { /* no rounding, but may still have overflow or subnormal */ +      /* [these tests are just for performance; finalize repeats them] */ +      if ((dn->exponent-1<set->emin-dn->digits) +       || (dn->exponent-1>set->emax-set->digits)) { +	residue=0; +	decFinalize(dn, set, &residue, &status); +	} +      } +    /* decNumberShow(dn); */ +    } while(0);				/* [for break] */ + +  if (allocres!=NULL) free(allocres);	/* drop any storage used */ +  if (status!=0) decStatus(dn, status, set); +  return dn; +  } /* decNumberFromString */ + +/* ================================================================== */ +/* Operators							      */ +/* ================================================================== */ + +/* ------------------------------------------------------------------ */ +/* decNumberAbs -- absolute value operator			      */ +/*								      */ +/*   This computes C = abs(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* See also decNumberCopyAbs for a quiet bitwise version of this.     */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* This has the same effect as decNumberPlus unless A is negative,    */ +/* in which case it has the same effect as decNumberMinus.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberAbs(decNumber *res, const decNumber *rhs, +			 decContext *set) { +  decNumber dzero;			/* for 0 */ +  uInt status=0;			/* accumulator */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  decNumberZero(&dzero);		/* set 0 */ +  dzero.exponent=rhs->exponent;		/* [no coefficient expansion] */ +  decAddOp(res, &dzero, rhs, set, (uByte)(rhs->bits & DECNEG), &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberAbs */ + +/* ------------------------------------------------------------------ */ +/* decNumberAdd -- add two Numbers				      */ +/*								      */ +/*   This computes C = A + B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X+X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* This just calls the routine shared with Subtract		      */ +decNumber * decNumberAdd(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decAddOp(res, lhs, rhs, set, 0, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberAdd */ + +/* ------------------------------------------------------------------ */ +/* decNumberAnd -- AND two Numbers, digitwise			      */ +/*								      */ +/*   This computes C = A & B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X&X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context (used for result length and error report)     */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Logical function restrictions apply (see above); a NaN is	      */ +/* returned with Invalid_operation if a restriction is violated.      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberAnd(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  const Unit *ua, *ub;			/* -> operands */ +  const Unit *msua, *msub;		/* -> operand msus */ +  Unit *uc,  *msuc;			/* -> result and its msu */ +  Int	msudigs;			/* digits in res msu */ +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  if (lhs->exponent!=0 || decNumberIsSpecial(lhs) || decNumberIsNegative(lhs) +   || rhs->exponent!=0 || decNumberIsSpecial(rhs) || decNumberIsNegative(rhs)) { +    decStatus(res, DEC_Invalid_operation, set); +    return res; +    } + +  /* operands are valid */ +  ua=lhs->lsu;				/* bottom-up */ +  ub=rhs->lsu;				/* .. */ +  uc=res->lsu;				/* .. */ +  msua=ua+D2U(lhs->digits)-1;		/* -> msu of lhs */ +  msub=ub+D2U(rhs->digits)-1;		/* -> msu of rhs */ +  msuc=uc+D2U(set->digits)-1;		/* -> msu of result */ +  msudigs=MSUDIGITS(set->digits);	/* [faster than remainder] */ +  for (; uc<=msuc; ua++, ub++, uc++) {	/* Unit loop */ +    Unit a, b;				/* extract units */ +    if (ua>msua) a=0; +     else a=*ua; +    if (ub>msub) b=0; +     else b=*ub; +    *uc=0;				/* can now write back */ +    if (a|b) {				/* maybe 1 bits to examine */ +      Int i, j; +      *uc=0;				/* can now write back */ +      /* This loop could be unrolled and/or use BIN2BCD tables */ +      for (i=0; i<DECDPUN; i++) { +	if (a&b&1) *uc=*uc+(Unit)powers[i];  /* effect AND */ +	j=a%10; +	a=a/10; +	j|=b%10; +	b=b/10; +	if (j>1) { +	  decStatus(res, DEC_Invalid_operation, set); +	  return res; +	  } +	if (uc==msuc && i==msudigs-1) break; /* just did final digit */ +	} /* each digit */ +      } /* both OK */ +    } /* each unit */ +  /* [here uc-1 is the msu of the result] */ +  res->digits=decGetDigits(res->lsu, uc-res->lsu); +  res->exponent=0;			/* integer */ +  res->bits=0;				/* sign=0 */ +  return res;  /* [no status to set] */ +  } /* decNumberAnd */ + +/* ------------------------------------------------------------------ */ +/* decNumberCompare -- compare two Numbers			      */ +/*								      */ +/*   This computes C = A ? B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for one digit (or NaN).			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCompare(decNumber *res, const decNumber *lhs, +			     const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPARE, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberCompare */ + +/* ------------------------------------------------------------------ */ +/* decNumberCompareSignal -- compare, signalling on all NaNs	      */ +/*								      */ +/*   This computes C = A ? B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for one digit (or NaN).			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCompareSignal(decNumber *res, const decNumber *lhs, +				   const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPSIG, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberCompareSignal */ + +/* ------------------------------------------------------------------ */ +/* decNumberCompareTotal -- compare two Numbers, using total ordering */ +/*								      */ +/*   This computes C = A ? B, under total ordering		      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for one digit; the result will always be one of  */ +/* -1, 0, or 1.							      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCompareTotal(decNumber *res, const decNumber *lhs, +				  const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPTOTAL, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberCompareTotal */ + +/* ------------------------------------------------------------------ */ +/* decNumberCompareTotalMag -- compare, total ordering of magnitudes  */ +/*								      */ +/*   This computes C = |A| ? |B|, under total ordering		      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for one digit; the result will always be one of  */ +/* -1, 0, or 1.							      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCompareTotalMag(decNumber *res, const decNumber *lhs, +				     const decNumber *rhs, decContext *set) { +  uInt status=0;		   /* accumulator */ +  uInt needbytes;		   /* for space calculations */ +  decNumber bufa[D2N(DECBUFFER+1)];/* +1 in case DECBUFFER=0 */ +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber bufb[D2N(DECBUFFER+1)]; +  decNumber *allocbufb=NULL;	   /* -> allocated bufb, iff allocated */ +  decNumber *a, *b;		   /* temporary pointers */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {					/* protect allocated storage */ +    /* if either is negative, take a copy and absolute */ +    if (decNumberIsNegative(lhs)) {	/* lhs<0 */ +      a=bufa; +      needbytes=sizeof(decNumber)+(D2U(lhs->digits)-1)*sizeof(Unit); +      if (needbytes>sizeof(bufa)) {	/* need malloc space */ +	allocbufa=(decNumber *)malloc(needbytes); +	if (allocbufa==NULL) {		/* hopeless -- abandon */ +	  status|=DEC_Insufficient_storage; +	  break;} +	a=allocbufa;			/* use the allocated space */ +	} +      decNumberCopy(a, lhs);		/* copy content */ +      a->bits&=~DECNEG;			/* .. and clear the sign */ +      lhs=a;				/* use copy from here on */ +      } +    if (decNumberIsNegative(rhs)) {	/* rhs<0 */ +      b=bufb; +      needbytes=sizeof(decNumber)+(D2U(rhs->digits)-1)*sizeof(Unit); +      if (needbytes>sizeof(bufb)) {	/* need malloc space */ +	allocbufb=(decNumber *)malloc(needbytes); +	if (allocbufb==NULL) {		/* hopeless -- abandon */ +	  status|=DEC_Insufficient_storage; +	  break;} +	b=allocbufb;			/* use the allocated space */ +	} +      decNumberCopy(b, rhs);		/* copy content */ +      b->bits&=~DECNEG;			/* .. and clear the sign */ +      rhs=b;				/* use copy from here on */ +      } +    decCompareOp(res, lhs, rhs, set, COMPTOTAL, &status); +    } while(0);				/* end protected */ + +  if (allocbufa!=NULL) free(allocbufa); /* drop any storage used */ +  if (allocbufb!=NULL) free(allocbufb); /* .. */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberCompareTotalMag */ + +/* ------------------------------------------------------------------ */ +/* decNumberDivide -- divide one number by another		      */ +/*								      */ +/*   This computes C = A / B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X/X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberDivide(decNumber *res, const decNumber *lhs, +			    const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decDivideOp(res, lhs, rhs, set, DIVIDE, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberDivide */ + +/* ------------------------------------------------------------------ */ +/* decNumberDivideInteger -- divide and return integer quotient	      */ +/*								      */ +/*   This computes C = A # B, where # is the integer divide operator  */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X#X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberDivideInteger(decNumber *res, const decNumber *lhs, +				   const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decDivideOp(res, lhs, rhs, set, DIVIDEINT, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberDivideInteger */ + +/* ------------------------------------------------------------------ */ +/* decNumberExp -- exponentiation				      */ +/*								      */ +/*   This computes C = exp(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Mathematical function restrictions apply (see above); a NaN is     */ +/* returned with Invalid_operation if a restriction is violated.      */ +/*								      */ +/* Finite results will always be full precision and Inexact, except   */ +/* when A is a zero or -Infinity (giving 1 or 0 respectively).	      */ +/*								      */ +/* An Inexact result is rounded using DEC_ROUND_HALF_EVEN; it will    */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/* ------------------------------------------------------------------ */ +/* This is a wrapper for decExpOp which can handle the slightly wider */ +/* (double) range needed by Ln (which has to be able to calculate     */ +/* exp(-a) where a can be the tiniest number (Ntiny).		      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberExp(decNumber *res, const decNumber *rhs, +			 decContext *set) { +  uInt status=0;			/* accumulator */ +  #if DECSUBSET +  decNumber *allocrhs=NULL;	   /* non-NULL if rounded rhs allocated */ +  #endif + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* Check restrictions; these restrictions ensure that if h=8 (see */ +  /* decExpOp) then the result will either overflow or underflow to 0. */ +  /* Other math functions restrict the input range, too, for inverses. */ +  /* If not violated then carry out the operation. */ +  if (!decCheckMath(rhs, set, &status)) do { /* protect allocation */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operand and set lostDigits status, as needed */ +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    decExpOp(res, rhs, set, &status); +    } while(0);				/* end protected */ + +  #if DECSUBSET +  if (allocrhs !=NULL) free(allocrhs);	/* drop any storage used */ +  #endif +  /* apply significant status */ +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberExp */ + +/* ------------------------------------------------------------------ */ +/* decNumberFMA -- fused multiply add				      */ +/*								      */ +/*   This computes D = (A * B) + C with only one rounding	      */ +/*								      */ +/*   res is D, the result.  D may be A or B or C (e.g., X=FMA(X,X,X)) */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   fhs is C [far hand side]					      */ +/*   set is the context						      */ +/*								      */ +/* Mathematical function restrictions apply (see above); a NaN is     */ +/* returned with Invalid_operation if a restriction is violated.      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberFMA(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, const decNumber *fhs, +			 decContext *set) { +  uInt status=0;		   /* accumulator */ +  decContext dcmul;		   /* context for the multiplication */ +  uInt needbytes;		   /* for space calculations */ +  decNumber bufa[D2N(DECBUFFER*2+1)]; +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *acc;		   /* accumulator pointer */ +  decNumber dzero;		   /* work */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  if (decCheckOperands(res, fhs, DECUNUSED, set)) return res; +  #endif + +  do {					/* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) {		/* [undefined if subset] */ +      status|=DEC_Invalid_operation; +      break;} +    #endif +    /* Check math restrictions [these ensure no overflow or underflow] */ +    if ((!decNumberIsSpecial(lhs) && decCheckMath(lhs, set, &status)) +     || (!decNumberIsSpecial(rhs) && decCheckMath(rhs, set, &status)) +     || (!decNumberIsSpecial(fhs) && decCheckMath(fhs, set, &status))) break; +    /* set up context for multiply */ +    dcmul=*set; +    dcmul.digits=lhs->digits+rhs->digits; /* just enough */ +    /* [The above may be an over-estimate for subset arithmetic, but that's OK] */ +    dcmul.emax=DEC_MAX_EMAX;		/* effectively unbounded .. */ +    dcmul.emin=DEC_MIN_EMIN;		/* [thanks to Math restrictions] */ +    /* set up decNumber space to receive the result of the multiply */ +    acc=bufa;				/* may fit */ +    needbytes=sizeof(decNumber)+(D2U(dcmul.digits)-1)*sizeof(Unit); +    if (needbytes>sizeof(bufa)) {	/* need malloc space */ +      allocbufa=(decNumber *)malloc(needbytes); +      if (allocbufa==NULL) {		/* hopeless -- abandon */ +	status|=DEC_Insufficient_storage; +	break;} +      acc=allocbufa;			/* use the allocated space */ +      } +    /* multiply with extended range and necessary precision */ +    /*printf("emin=%ld\n", dcmul.emin); */ +    decMultiplyOp(acc, lhs, rhs, &dcmul, &status); +    /* Only Invalid operation (from sNaN or Inf * 0) is possible in */ +    /* status; if either is seen than ignore fhs (in case it is */ +    /* another sNaN) and set acc to NaN unless we had an sNaN */ +    /* [decMultiplyOp leaves that to caller] */ +    /* Note sNaN has to go through addOp to shorten payload if */ +    /* necessary */ +    if ((status&DEC_Invalid_operation)!=0) { +      if (!(status&DEC_sNaN)) {		/* but be true invalid */ +	decNumberZero(res);		/* acc not yet set */ +	res->bits=DECNAN; +	break; +	} +      decNumberZero(&dzero);		/* make 0 (any non-NaN would do) */ +      fhs=&dzero;			/* use that */ +      } +    #if DECCHECK +     else { /* multiply was OK */ +      if (status!=0) printf("Status=%08lx after FMA multiply\n", status); +      } +    #endif +    /* add the third operand and result -> res, and all is done */ +    decAddOp(res, acc, fhs, set, 0, &status); +    } while(0);				/* end protected */ + +  if (allocbufa!=NULL) free(allocbufa); /* drop any storage used */ +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberFMA */ + +/* ------------------------------------------------------------------ */ +/* decNumberInvert -- invert a Number, digitwise		      */ +/*								      */ +/*   This computes C = ~A					      */ +/*								      */ +/*   res is C, the result.  C may be A (e.g., X=~X)		      */ +/*   rhs is A							      */ +/*   set is the context (used for result length and error report)     */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Logical function restrictions apply (see above); a NaN is	      */ +/* returned with Invalid_operation if a restriction is violated.      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberInvert(decNumber *res, const decNumber *rhs, +			    decContext *set) { +  const Unit *ua, *msua;		/* -> operand and its msu */ +  Unit	*uc, *msuc;			/* -> result and its msu */ +  Int	msudigs;			/* digits in res msu */ +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  if (rhs->exponent!=0 || decNumberIsSpecial(rhs) || decNumberIsNegative(rhs)) { +    decStatus(res, DEC_Invalid_operation, set); +    return res; +    } +  /* operand is valid */ +  ua=rhs->lsu;				/* bottom-up */ +  uc=res->lsu;				/* .. */ +  msua=ua+D2U(rhs->digits)-1;		/* -> msu of rhs */ +  msuc=uc+D2U(set->digits)-1;		/* -> msu of result */ +  msudigs=MSUDIGITS(set->digits);	/* [faster than remainder] */ +  for (; uc<=msuc; ua++, uc++) {	/* Unit loop */ +    Unit a;				/* extract unit */ +    Int	 i, j;				/* work */ +    if (ua>msua) a=0; +     else a=*ua; +    *uc=0;				/* can now write back */ +    /* always need to examine all bits in rhs */ +    /* This loop could be unrolled and/or use BIN2BCD tables */ +    for (i=0; i<DECDPUN; i++) { +      if ((~a)&1) *uc=*uc+(Unit)powers[i];   /* effect INVERT */ +      j=a%10; +      a=a/10; +      if (j>1) { +	decStatus(res, DEC_Invalid_operation, set); +	return res; +	} +      if (uc==msuc && i==msudigs-1) break;   /* just did final digit */ +      } /* each digit */ +    } /* each unit */ +  /* [here uc-1 is the msu of the result] */ +  res->digits=decGetDigits(res->lsu, uc-res->lsu); +  res->exponent=0;			/* integer */ +  res->bits=0;				/* sign=0 */ +  return res;  /* [no status to set] */ +  } /* decNumberInvert */ + +/* ------------------------------------------------------------------ */ +/* decNumberLn -- natural logarithm				      */ +/*								      */ +/*   This computes C = ln(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Notable cases:						      */ +/*   A<0 -> Invalid						      */ +/*   A=0 -> -Infinity (Exact)					      */ +/*   A=+Infinity -> +Infinity (Exact)				      */ +/*   A=1 exactly -> 0 (Exact)					      */ +/*								      */ +/* Mathematical function restrictions apply (see above); a NaN is     */ +/* returned with Invalid_operation if a restriction is violated.      */ +/*								      */ +/* An Inexact result is rounded using DEC_ROUND_HALF_EVEN; it will    */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/* ------------------------------------------------------------------ */ +/* This is a wrapper for decLnOp which can handle the slightly wider  */ +/* (+11) range needed by Ln, Log10, etc. (which may have to be able   */ +/* to calculate at p+e+2).					      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberLn(decNumber *res, const decNumber *rhs, +			decContext *set) { +  uInt status=0;		   /* accumulator */ +  #if DECSUBSET +  decNumber *allocrhs=NULL;	   /* non-NULL if rounded rhs allocated */ +  #endif + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* Check restrictions; this is a math function; if not violated */ +  /* then carry out the operation. */ +  if (!decCheckMath(rhs, set, &status)) do { /* protect allocation */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operand and set lostDigits status, as needed */ +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      /* special check in subset for rhs=0 */ +      if (ISZERO(rhs)) {		/* +/- zeros -> error */ +	status|=DEC_Invalid_operation; +	break;} +      } /* extended=0 */ +    #endif +    decLnOp(res, rhs, set, &status); +    } while(0);				/* end protected */ + +  #if DECSUBSET +  if (allocrhs !=NULL) free(allocrhs);	/* drop any storage used */ +  #endif +  /* apply significant status */ +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberLn */ + +/* ------------------------------------------------------------------ */ +/* decNumberLogB - get adjusted exponent, by 754r rules		      */ +/*								      */ +/*   This computes C = adjustedexponent(A)			      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context, used only for digits and status	      */ +/*								      */ +/* C must have space for 10 digits (A might have 10**9 digits and     */ +/* an exponent of +999999999, or one digit and an exponent of	      */ +/* -1999999999).						      */ +/*								      */ +/* This returns the adjusted exponent of A after (in theory) padding  */ +/* with zeros on the right to set->digits digits while keeping the    */ +/* same value.	The exponent is not limited by emin/emax.	      */ +/*								      */ +/* Notable cases:						      */ +/*   A<0 -> Use |A|						      */ +/*   A=0 -> -Infinity (Division by zero)			      */ +/*   A=Infinite -> +Infinity (Exact)				      */ +/*   A=1 exactly -> 0 (Exact)					      */ +/*   NaNs are propagated as usual				      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberLogB(decNumber *res, const decNumber *rhs, +			  decContext *set) { +  uInt status=0;		   /* accumulator */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* NaNs as usual; Infinities return +Infinity; 0->oops */ +  if (decNumberIsNaN(rhs)) decNaNs(res, rhs, NULL, set, &status); +   else if (decNumberIsInfinite(rhs)) decNumberCopyAbs(res, rhs); +   else if (decNumberIsZero(rhs)) { +    decNumberZero(res);			/* prepare for Infinity */ +    res->bits=DECNEG|DECINF;		/* -Infinity */ +    status|=DEC_Division_by_zero;	/* as per 754r */ +    } +   else { /* finite non-zero */ +    Int ae=rhs->exponent+rhs->digits-1; /* adjusted exponent */ +    decNumberFromInt32(res, ae);	/* lay it out */ +    } + +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberLogB */ + +/* ------------------------------------------------------------------ */ +/* decNumberLog10 -- logarithm in base 10			      */ +/*								      */ +/*   This computes C = log10(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Notable cases:						      */ +/*   A<0 -> Invalid						      */ +/*   A=0 -> -Infinity (Exact)					      */ +/*   A=+Infinity -> +Infinity (Exact)				      */ +/*   A=10**n (if n is an integer) -> n (Exact)			      */ +/*								      */ +/* Mathematical function restrictions apply (see above); a NaN is     */ +/* returned with Invalid_operation if a restriction is violated.      */ +/*								      */ +/* An Inexact result is rounded using DEC_ROUND_HALF_EVEN; it will    */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/* ------------------------------------------------------------------ */ +/* This calculates ln(A)/ln(10) using appropriate precision.  For     */ +/* ln(A) this is the max(p, rhs->digits + t) + 3, where p is the      */ +/* requested digits and t is the number of digits in the exponent     */ +/* (maximum 6).	 For ln(10) it is p + 3; this is often handled by the */ +/* fastpath in decLnOp.	 The final division is done to the requested  */ +/* precision.							      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberLog10(decNumber *res, const decNumber *rhs, +			  decContext *set) { +  uInt status=0, ignore=0;	   /* status accumulators */ +  uInt needbytes;		   /* for space calculations */ +  Int p;			   /* working precision */ +  Int t;			   /* digits in exponent of A */ + +  /* buffers for a and b working decimals */ +  /* (adjustment calculator, same size) */ +  decNumber bufa[D2N(DECBUFFER+2)]; +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *a=bufa;		   /* temporary a */ +  decNumber bufb[D2N(DECBUFFER+2)]; +  decNumber *allocbufb=NULL;	   /* -> allocated bufb, iff allocated */ +  decNumber *b=bufb;		   /* temporary b */ +  decNumber bufw[D2N(10)];	   /* working 2-10 digit number */ +  decNumber *w=bufw;		   /* .. */ +  #if DECSUBSET +  decNumber *allocrhs=NULL;	   /* non-NULL if rounded rhs allocated */ +  #endif + +  decContext aset;		   /* working context */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* Check restrictions; this is a math function; if not violated */ +  /* then carry out the operation. */ +  if (!decCheckMath(rhs, set, &status)) do { /* protect malloc */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operand and set lostDigits status, as needed */ +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      /* special check in subset for rhs=0 */ +      if (ISZERO(rhs)) {		/* +/- zeros -> error */ +	status|=DEC_Invalid_operation; +	break;} +      } /* extended=0 */ +    #endif + +    decContextDefault(&aset, DEC_INIT_DECIMAL64); /* clean context */ + +    /* handle exact powers of 10; only check if +ve finite */ +    if (!(rhs->bits&(DECNEG|DECSPECIAL)) && !ISZERO(rhs)) { +      Int residue=0;		   /* (no residue) */ +      uInt copystat=0;		   /* clean status */ + +      /* round to a single digit... */ +      aset.digits=1; +      decCopyFit(w, rhs, &aset, &residue, ©stat); /* copy & shorten */ +      /* if exact and the digit is 1, rhs is a power of 10 */ +      if (!(copystat&DEC_Inexact) && w->lsu[0]==1) { +	/* the exponent, conveniently, is the power of 10; making */ +	/* this the result needs a little care as it might not fit, */ +	/* so first convert it into the working number, and then move */ +	/* to res */ +	decNumberFromInt32(w, w->exponent); +	residue=0; +	decCopyFit(res, w, set, &residue, &status); /* copy & round */ +	decFinish(res, set, &residue, &status);	    /* cleanup/set flags */ +	break; +	} /* not a power of 10 */ +      } /* not a candidate for exact */ + +    /* simplify the information-content calculation to use 'total */ +    /* number of digits in a, including exponent' as compared to the */ +    /* requested digits, as increasing this will only rarely cost an */ +    /* iteration in ln(a) anyway */ +    t=6;				/* it can never be >6 */ + +    /* allocate space when needed... */ +    p=(rhs->digits+t>set->digits?rhs->digits+t:set->digits)+3; +    needbytes=sizeof(decNumber)+(D2U(p)-1)*sizeof(Unit); +    if (needbytes>sizeof(bufa)) {	/* need malloc space */ +      allocbufa=(decNumber *)malloc(needbytes); +      if (allocbufa==NULL) {		/* hopeless -- abandon */ +	status|=DEC_Insufficient_storage; +	break;} +      a=allocbufa;			/* use the allocated space */ +      } +    aset.digits=p;			/* as calculated */ +    aset.emax=DEC_MAX_MATH;		/* usual bounds */ +    aset.emin=-DEC_MAX_MATH;		/* .. */ +    aset.clamp=0;			/* and no concrete format */ +    decLnOp(a, rhs, &aset, &status);	/* a=ln(rhs) */ + +    /* skip the division if the result so far is infinite, NaN, or */ +    /* zero, or there was an error; note NaN from sNaN needs copy */ +    if (status&DEC_NaNs && !(status&DEC_sNaN)) break; +    if (a->bits&DECSPECIAL || ISZERO(a)) { +      decNumberCopy(res, a);		/* [will fit] */ +      break;} + +    /* for ln(10) an extra 3 digits of precision are needed */ +    p=set->digits+3; +    needbytes=sizeof(decNumber)+(D2U(p)-1)*sizeof(Unit); +    if (needbytes>sizeof(bufb)) {	/* need malloc space */ +      allocbufb=(decNumber *)malloc(needbytes); +      if (allocbufb==NULL) {		/* hopeless -- abandon */ +	status|=DEC_Insufficient_storage; +	break;} +      b=allocbufb;			/* use the allocated space */ +      } +    decNumberZero(w);			/* set up 10... */ +    #if DECDPUN==1 +    w->lsu[1]=1; w->lsu[0]=0;		/* .. */ +    #else +    w->lsu[0]=10;			/* .. */ +    #endif +    w->digits=2;			/* .. */ + +    aset.digits=p; +    decLnOp(b, w, &aset, &ignore);	/* b=ln(10) */ + +    aset.digits=set->digits;		/* for final divide */ +    decDivideOp(res, a, b, &aset, DIVIDE, &status); /* into result */ +    } while(0);				/* [for break] */ + +  if (allocbufa!=NULL) free(allocbufa); /* drop any storage used */ +  if (allocbufb!=NULL) free(allocbufb); /* .. */ +  #if DECSUBSET +  if (allocrhs !=NULL) free(allocrhs);	/* .. */ +  #endif +  /* apply significant status */ +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberLog10 */ + +/* ------------------------------------------------------------------ */ +/* decNumberMax -- compare two Numbers and return the maximum	      */ +/*								      */ +/*   This computes C = A ? B, returning the maximum by 754R rules     */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMax(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPMAX, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMax */ + +/* ------------------------------------------------------------------ */ +/* decNumberMaxMag -- compare and return the maximum by magnitude     */ +/*								      */ +/*   This computes C = A ? B, returning the maximum by 754R rules     */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMaxMag(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPMAXMAG, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMaxMag */ + +/* ------------------------------------------------------------------ */ +/* decNumberMin -- compare two Numbers and return the minimum	      */ +/*								      */ +/*   This computes C = A ? B, returning the minimum by 754R rules     */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMin(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPMIN, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMin */ + +/* ------------------------------------------------------------------ */ +/* decNumberMinMag -- compare and return the minimum by magnitude     */ +/*								      */ +/*   This computes C = A ? B, returning the minimum by 754R rules     */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMinMag(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decCompareOp(res, lhs, rhs, set, COMPMINMAG, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMinMag */ + +/* ------------------------------------------------------------------ */ +/* decNumberMinus -- prefix minus operator			      */ +/*								      */ +/*   This computes C = 0 - A					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* See also decNumberCopyNegate for a quiet bitwise version of this.  */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* Simply use AddOp for the subtract, which will do the necessary.    */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMinus(decNumber *res, const decNumber *rhs, +			   decContext *set) { +  decNumber dzero; +  uInt status=0;			/* accumulator */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  decNumberZero(&dzero);		/* make 0 */ +  dzero.exponent=rhs->exponent;		/* [no coefficient expansion] */ +  decAddOp(res, &dzero, rhs, set, DECNEG, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMinus */ + +/* ------------------------------------------------------------------ */ +/* decNumberNextMinus -- next towards -Infinity			      */ +/*								      */ +/*   This computes C = A - infinitesimal, rounded towards -Infinity   */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* This is a generalization of 754r NextDown.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberNextMinus(decNumber *res, const decNumber *rhs, +			       decContext *set) { +  decNumber dtiny;			     /* constant */ +  decContext workset=*set;		     /* work */ +  uInt status=0;			     /* accumulator */ +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* +Infinity is the special case */ +  if ((rhs->bits&(DECINF|DECNEG))==DECINF) { +    decSetMaxValue(res, set);		     /* is +ve */ +    /* there is no status to set */ +    return res; +    } +  decNumberZero(&dtiny);		     /* start with 0 */ +  dtiny.lsu[0]=1;			     /* make number that is .. */ +  dtiny.exponent=DEC_MIN_EMIN-1;	     /* .. smaller than tiniest */ +  workset.round=DEC_ROUND_FLOOR; +  decAddOp(res, rhs, &dtiny, &workset, DECNEG, &status); +  status&=DEC_Invalid_operation|DEC_sNaN;    /* only sNaN Invalid please */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberNextMinus */ + +/* ------------------------------------------------------------------ */ +/* decNumberNextPlus -- next towards +Infinity			      */ +/*								      */ +/*   This computes C = A + infinitesimal, rounded towards +Infinity   */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* This is a generalization of 754r NextUp.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberNextPlus(decNumber *res, const decNumber *rhs, +			      decContext *set) { +  decNumber dtiny;			     /* constant */ +  decContext workset=*set;		     /* work */ +  uInt status=0;			     /* accumulator */ +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* -Infinity is the special case */ +  if ((rhs->bits&(DECINF|DECNEG))==(DECINF|DECNEG)) { +    decSetMaxValue(res, set); +    res->bits=DECNEG;			     /* negative */ +    /* there is no status to set */ +    return res; +    } +  decNumberZero(&dtiny);		     /* start with 0 */ +  dtiny.lsu[0]=1;			     /* make number that is .. */ +  dtiny.exponent=DEC_MIN_EMIN-1;	     /* .. smaller than tiniest */ +  workset.round=DEC_ROUND_CEILING; +  decAddOp(res, rhs, &dtiny, &workset, 0, &status); +  status&=DEC_Invalid_operation|DEC_sNaN;    /* only sNaN Invalid please */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberNextPlus */ + +/* ------------------------------------------------------------------ */ +/* decNumberNextToward -- next towards rhs			      */ +/*								      */ +/*   This computes C = A +/- infinitesimal, rounded towards	      */ +/*   +/-Infinity in the direction of B, as per 754r nextafter rules   */ +/*								      */ +/*   res is C, the result.  C may be A or B.			      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* This is a generalization of 754r NextAfter.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberNextToward(decNumber *res, const decNumber *lhs, +				const decNumber *rhs, decContext *set) { +  decNumber dtiny;			     /* constant */ +  decContext workset=*set;		     /* work */ +  Int result;				     /* .. */ +  uInt status=0;			     /* accumulator */ +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  if (decNumberIsNaN(lhs) || decNumberIsNaN(rhs)) { +    decNaNs(res, lhs, rhs, set, &status); +    } +   else { /* Is numeric, so no chance of sNaN Invalid, etc. */ +    result=decCompare(lhs, rhs, 0);	/* sign matters */ +    if (result==BADINT) status|=DEC_Insufficient_storage; /* rare */ +     else { /* valid compare */ +      if (result==0) decNumberCopySign(res, lhs, rhs); /* easy */ +       else { /* differ: need NextPlus or NextMinus */ +	uByte sub;			/* add or subtract */ +	if (result<0) {			/* lhs<rhs, do nextplus */ +	  /* -Infinity is the special case */ +	  if ((lhs->bits&(DECINF|DECNEG))==(DECINF|DECNEG)) { +	    decSetMaxValue(res, set); +	    res->bits=DECNEG;		/* negative */ +	    return res;			/* there is no status to set */ +	    } +	  workset.round=DEC_ROUND_CEILING; +	  sub=0;			/* add, please */ +	  } /* plus */ +	 else {				/* lhs>rhs, do nextminus */ +	  /* +Infinity is the special case */ +	  if ((lhs->bits&(DECINF|DECNEG))==DECINF) { +	    decSetMaxValue(res, set); +	    return res;			/* there is no status to set */ +	    } +	  workset.round=DEC_ROUND_FLOOR; +	  sub=DECNEG;			/* subtract, please */ +	  } /* minus */ +	decNumberZero(&dtiny);		/* start with 0 */ +	dtiny.lsu[0]=1;			/* make number that is .. */ +	dtiny.exponent=DEC_MIN_EMIN-1;	/* .. smaller than tiniest */ +	decAddOp(res, lhs, &dtiny, &workset, sub, &status); /* + or - */ +	/* turn off exceptions if the result is a normal number */ +	/* (including Nmin), otherwise let all status through */ +	if (decNumberIsNormal(res, set)) status=0; +	} /* unequal */ +      } /* compare OK */ +    } /* numeric */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberNextToward */ + +/* ------------------------------------------------------------------ */ +/* decNumberOr -- OR two Numbers, digitwise			      */ +/*								      */ +/*   This computes C = A | B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X|X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context (used for result length and error report)     */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Logical function restrictions apply (see above); a NaN is	      */ +/* returned with Invalid_operation if a restriction is violated.      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberOr(decNumber *res, const decNumber *lhs, +			const decNumber *rhs, decContext *set) { +  const Unit *ua, *ub;			/* -> operands */ +  const Unit *msua, *msub;		/* -> operand msus */ +  Unit	*uc, *msuc;			/* -> result and its msu */ +  Int	msudigs;			/* digits in res msu */ +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  if (lhs->exponent!=0 || decNumberIsSpecial(lhs) || decNumberIsNegative(lhs) +   || rhs->exponent!=0 || decNumberIsSpecial(rhs) || decNumberIsNegative(rhs)) { +    decStatus(res, DEC_Invalid_operation, set); +    return res; +    } +  /* operands are valid */ +  ua=lhs->lsu;				/* bottom-up */ +  ub=rhs->lsu;				/* .. */ +  uc=res->lsu;				/* .. */ +  msua=ua+D2U(lhs->digits)-1;		/* -> msu of lhs */ +  msub=ub+D2U(rhs->digits)-1;		/* -> msu of rhs */ +  msuc=uc+D2U(set->digits)-1;		/* -> msu of result */ +  msudigs=MSUDIGITS(set->digits);	/* [faster than remainder] */ +  for (; uc<=msuc; ua++, ub++, uc++) {	/* Unit loop */ +    Unit a, b;				/* extract units */ +    if (ua>msua) a=0; +     else a=*ua; +    if (ub>msub) b=0; +     else b=*ub; +    *uc=0;				/* can now write back */ +    if (a|b) {				/* maybe 1 bits to examine */ +      Int i, j; +      /* This loop could be unrolled and/or use BIN2BCD tables */ +      for (i=0; i<DECDPUN; i++) { +	if ((a|b)&1) *uc=*uc+(Unit)powers[i];	  /* effect OR */ +	j=a%10; +	a=a/10; +	j|=b%10; +	b=b/10; +	if (j>1) { +	  decStatus(res, DEC_Invalid_operation, set); +	  return res; +	  } +	if (uc==msuc && i==msudigs-1) break;	  /* just did final digit */ +	} /* each digit */ +      } /* non-zero */ +    } /* each unit */ +  /* [here uc-1 is the msu of the result] */ +  res->digits=decGetDigits(res->lsu, uc-res->lsu); +  res->exponent=0;			/* integer */ +  res->bits=0;				/* sign=0 */ +  return res;  /* [no status to set] */ +  } /* decNumberOr */ + +/* ------------------------------------------------------------------ */ +/* decNumberPlus -- prefix plus operator			      */ +/*								      */ +/*   This computes C = 0 + A					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* See also decNumberCopy for a quiet bitwise version of this.	      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* This simply uses AddOp; Add will take fast path after preparing A. */ +/* Performance is a concern here, as this routine is often used to    */ +/* check operands and apply rounding and overflow/underflow testing.  */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberPlus(decNumber *res, const decNumber *rhs, +			  decContext *set) { +  decNumber dzero; +  uInt status=0;			/* accumulator */ +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  decNumberZero(&dzero);		/* make 0 */ +  dzero.exponent=rhs->exponent;		/* [no coefficient expansion] */ +  decAddOp(res, &dzero, rhs, set, 0, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberPlus */ + +/* ------------------------------------------------------------------ */ +/* decNumberMultiply -- multiply two Numbers			      */ +/*								      */ +/*   This computes C = A x B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X+X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberMultiply(decNumber *res, const decNumber *lhs, +			      const decNumber *rhs, decContext *set) { +  uInt status=0;		   /* accumulator */ +  decMultiplyOp(res, lhs, rhs, set, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberMultiply */ + +/* ------------------------------------------------------------------ */ +/* decNumberPower -- raise a number to a power			      */ +/*								      */ +/*   This computes C = A ** B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X**X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Mathematical function restrictions apply (see above); a NaN is     */ +/* returned with Invalid_operation if a restriction is violated.      */ +/*								      */ +/* However, if 1999999997<=B<=999999999 and B is an integer then the  */ +/* restrictions on A and the context are relaxed to the usual bounds, */ +/* for compatibility with the earlier (integer power only) version    */ +/* of this function.						      */ +/*								      */ +/* When B is an integer, the result may be exact, even if rounded.    */ +/*								      */ +/* The final result is rounded according to the context; it will      */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberPower(decNumber *res, const decNumber *lhs, +			   const decNumber *rhs, decContext *set) { +  #if DECSUBSET +  decNumber *alloclhs=NULL;	   /* non-NULL if rounded lhs allocated */ +  decNumber *allocrhs=NULL;	   /* .., rhs */ +  #endif +  decNumber *allocdac=NULL;	   /* -> allocated acc buffer, iff used */ +  decNumber *allocinv=NULL;	   /* -> allocated 1/x buffer, iff used */ +  Int	reqdigits=set->digits;	   /* requested DIGITS */ +  Int	n;			   /* rhs in binary */ +  Flag	rhsint=0;		   /* 1 if rhs is an integer */ +  Flag	useint=0;		   /* 1 if can use integer calculation */ +  Flag	isoddint=0;		   /* 1 if rhs is an integer and odd */ +  Int	i;			   /* work */ +  #if DECSUBSET +  Int	dropped;		   /* .. */ +  #endif +  uInt	needbytes;		   /* buffer size needed */ +  Flag	seenbit;		   /* seen a bit while powering */ +  Int	residue=0;		   /* rounding residue */ +  uInt	status=0;		   /* accumulators */ +  uByte bits=0;			   /* result sign if errors */ +  decContext aset;		   /* working context */ +  decNumber dnOne;		   /* work value 1... */ +  /* local accumulator buffer [a decNumber, with digits+elength+1 digits] */ +  decNumber dacbuff[D2N(DECBUFFER+9)]; +  decNumber *dac=dacbuff;	   /* -> result accumulator */ +  /* same again for possible 1/lhs calculation */ +  decNumber invbuff[D2N(DECBUFFER+9)]; + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { /* reduce operands and set status, as needed */ +      if (lhs->digits>reqdigits) { +	alloclhs=decRoundOperand(lhs, set, &status); +	if (alloclhs==NULL) break; +	lhs=alloclhs; +	} +      if (rhs->digits>reqdigits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* handle NaNs and rhs Infinity (lhs infinity is harder) */ +    if (SPECIALARGS) { +      if (decNumberIsNaN(lhs) || decNumberIsNaN(rhs)) { /* NaNs */ +	decNaNs(res, lhs, rhs, set, &status); +	break;} +      if (decNumberIsInfinite(rhs)) {	/* rhs Infinity */ +	Flag rhsneg=rhs->bits&DECNEG;	/* save rhs sign */ +	if (decNumberIsNegative(lhs)	/* lhs<0 */ +	 && !decNumberIsZero(lhs))	/* .. */ +	  status|=DEC_Invalid_operation; +	 else {				/* lhs >=0 */ +	  decNumberZero(&dnOne);	/* set up 1 */ +	  dnOne.lsu[0]=1; +	  decNumberCompare(dac, lhs, &dnOne, set); /* lhs ? 1 */ +	  decNumberZero(res);		/* prepare for 0/1/Infinity */ +	  if (decNumberIsNegative(dac)) {    /* lhs<1 */ +	    if (rhsneg) res->bits|=DECINF;   /* +Infinity [else is +0] */ +	    } +	   else if (dac->lsu[0]==0) {	     /* lhs=1 */ +	    /* 1**Infinity is inexact, so return fully-padded 1.0000 */ +	    Int shift=set->digits-1; +	    *res->lsu=1;		     /* was 0, make int 1 */ +	    res->digits=decShiftToMost(res->lsu, 1, shift); +	    res->exponent=-shift;	     /* make 1.0000... */ +	    status|=DEC_Inexact|DEC_Rounded; /* deemed inexact */ +	    } +	   else {			     /* lhs>1 */ +	    if (!rhsneg) res->bits|=DECINF;  /* +Infinity [else is +0] */ +	    } +	  } /* lhs>=0 */ +	break;} +      /* [lhs infinity drops through] */ +      } /* specials */ + +    /* Original rhs may be an integer that fits and is in range */ +    n=decGetInt(rhs); +    if (n!=BADINT) {			/* it is an integer */ +      rhsint=1;				/* record the fact for 1**n */ +      isoddint=(Flag)n&1;		/* [works even if big] */ +      if (n!=BIGEVEN && n!=BIGODD)	/* can use integer path? */ +	useint=1;			/* looks good */ +      } + +    if (decNumberIsNegative(lhs)	/* -x .. */ +      && isoddint) bits=DECNEG;		/* .. to an odd power */ + +    /* handle LHS infinity */ +    if (decNumberIsInfinite(lhs)) {	/* [NaNs already handled] */ +      uByte rbits=rhs->bits;		/* save */ +      decNumberZero(res);		/* prepare */ +      if (n==0) *res->lsu=1;		/* [-]Inf**0 => 1 */ +       else { +	/* -Inf**nonint -> error */ +	if (!rhsint && decNumberIsNegative(lhs)) { +	  status|=DEC_Invalid_operation;     /* -Inf**nonint is error */ +	  break;} +	if (!(rbits & DECNEG)) bits|=DECINF; /* was not a **-n */ +	/* [otherwise will be 0 or -0] */ +	res->bits=bits; +	} +      break;} + +    /* similarly handle LHS zero */ +    if (decNumberIsZero(lhs)) { +      if (n==0) {			     /* 0**0 => Error */ +	#if DECSUBSET +	if (!set->extended) {		     /* [unless subset] */ +	  decNumberZero(res); +	  *res->lsu=1;			     /* return 1 */ +	  break;} +	#endif +	status|=DEC_Invalid_operation; +	} +       else {				     /* 0**x */ +	uByte rbits=rhs->bits;		     /* save */ +	if (rbits & DECNEG) {		     /* was a 0**(-n) */ +	  #if DECSUBSET +	  if (!set->extended) {		     /* [bad if subset] */ +	    status|=DEC_Invalid_operation; +	    break;} +	  #endif +	  bits|=DECINF; +	  } +	decNumberZero(res);		     /* prepare */ +	/* [otherwise will be 0 or -0] */ +	res->bits=bits; +	} +      break;} + +    /* here both lhs and rhs are finite; rhs==0 is handled in the */ +    /* integer path.  Next handle the non-integer cases */ +    if (!useint) {			/* non-integral rhs */ +      /* any -ve lhs is bad, as is either operand or context out of */ +      /* bounds */ +      if (decNumberIsNegative(lhs)) { +	status|=DEC_Invalid_operation; +	break;} +      if (decCheckMath(lhs, set, &status) +       || decCheckMath(rhs, set, &status)) break; /* variable status */ + +      decContextDefault(&aset, DEC_INIT_DECIMAL64); /* clean context */ +      aset.emax=DEC_MAX_MATH;		/* usual bounds */ +      aset.emin=-DEC_MAX_MATH;		/* .. */ +      aset.clamp=0;			/* and no concrete format */ + +      /* calculate the result using exp(ln(lhs)*rhs), which can */ +      /* all be done into the accumulator, dac.	 The precision needed */ +      /* is enough to contain the full information in the lhs (which */ +      /* is the total digits, including exponent), or the requested */ +      /* precision, if larger, + 4; 6 is used for the exponent */ +      /* maximum length, and this is also used when it is shorter */ +      /* than the requested digits as it greatly reduces the >0.5 ulp */ +      /* cases at little cost (because Ln doubles digits each */ +      /* iteration so a few extra digits rarely causes an extra */ +      /* iteration) */ +      aset.digits=MAXI(lhs->digits, set->digits)+6+4; +      } /* non-integer rhs */ + +     else { /* rhs is in-range integer */ +      if (n==0) {			/* x**0 = 1 */ +	/* (0**0 was handled above) */ +	decNumberZero(res);		/* result=1 */ +	*res->lsu=1;			/* .. */ +	break;} +      /* rhs is a non-zero integer */ +      if (n<0) n=-n;			/* use abs(n) */ + +      aset=*set;			/* clone the context */ +      aset.round=DEC_ROUND_HALF_EVEN;	/* internally use balanced */ +      /* calculate the working DIGITS */ +      aset.digits=reqdigits+(rhs->digits+rhs->exponent)+2; +      #if DECSUBSET +      if (!set->extended) aset.digits--;     /* use classic precision */ +      #endif +      /* it's an error if this is more than can be handled */ +      if (aset.digits>DECNUMMAXP) {status|=DEC_Invalid_operation; break;} +      } /* integer path */ + +    /* aset.digits is the count of digits for the accumulator needed */ +    /* if accumulator is too long for local storage, then allocate */ +    needbytes=sizeof(decNumber)+(D2U(aset.digits)-1)*sizeof(Unit); +    /* [needbytes also used below if 1/lhs needed] */ +    if (needbytes>sizeof(dacbuff)) { +      allocdac=(decNumber *)malloc(needbytes); +      if (allocdac==NULL) {   /* hopeless -- abandon */ +	status|=DEC_Insufficient_storage; +	break;} +      dac=allocdac;	      /* use the allocated space */ +      } +    /* here, aset is set up and accumulator is ready for use */ + +    if (!useint) {			     /* non-integral rhs */ +      /* x ** y; special-case x=1 here as it will otherwise always */ +      /* reduce to integer 1; decLnOp has a fastpath which detects */ +      /* the case of x=1 */ +      decLnOp(dac, lhs, &aset, &status);     /* dac=ln(lhs) */ +      /* [no error possible, as lhs 0 already handled] */ +      if (ISZERO(dac)) {		     /* x==1, 1.0, etc. */ +	/* need to return fully-padded 1.0000 etc., but rhsint->1 */ +	*dac->lsu=1;			     /* was 0, make int 1 */ +	if (!rhsint) {			     /* add padding */ +	  Int shift=set->digits-1; +	  dac->digits=decShiftToMost(dac->lsu, 1, shift); +	  dac->exponent=-shift;		     /* make 1.0000... */ +	  status|=DEC_Inexact|DEC_Rounded;   /* deemed inexact */ +	  } +	} +       else { +	decMultiplyOp(dac, dac, rhs, &aset, &status);  /* dac=dac*rhs */ +	decExpOp(dac, dac, &aset, &status);	       /* dac=exp(dac) */ +	} +      /* and drop through for final rounding */ +      } /* non-integer rhs */ + +     else {				/* carry on with integer */ +      decNumberZero(dac);		/* acc=1 */ +      *dac->lsu=1;			/* .. */ + +      /* if a negative power the constant 1 is needed, and if not subset */ +      /* invert the lhs now rather than inverting the result later */ +      if (decNumberIsNegative(rhs)) {	/* was a **-n [hence digits>0] */ +	decNumber *inv=invbuff;		/* asssume use fixed buffer */ +	decNumberCopy(&dnOne, dac);	/* dnOne=1;  [needed now or later] */ +	#if DECSUBSET +	if (set->extended) {		/* need to calculate 1/lhs */ +	#endif +	  /* divide lhs into 1, putting result in dac [dac=1/dac] */ +	  decDivideOp(dac, &dnOne, lhs, &aset, DIVIDE, &status); +	  /* now locate or allocate space for the inverted lhs */ +	  if (needbytes>sizeof(invbuff)) { +	    allocinv=(decNumber *)malloc(needbytes); +	    if (allocinv==NULL) {	/* hopeless -- abandon */ +	      status|=DEC_Insufficient_storage; +	      break;} +	    inv=allocinv;		/* use the allocated space */ +	    } +	  /* [inv now points to big-enough buffer or allocated storage] */ +	  decNumberCopy(inv, dac);	/* copy the 1/lhs */ +	  decNumberCopy(dac, &dnOne);	/* restore acc=1 */ +	  lhs=inv;			/* .. and go forward with new lhs */ +	#if DECSUBSET +	  } +	#endif +	} + +      /* Raise-to-the-power loop... */ +      seenbit=0;		   /* set once a 1-bit is encountered */ +      for (i=1;;i++){		   /* for each bit [top bit ignored] */ +	/* abandon if had overflow or terminal underflow */ +	if (status & (DEC_Overflow|DEC_Underflow)) { /* interesting? */ +	  if (status&DEC_Overflow || ISZERO(dac)) break; +	  } +	/* [the following two lines revealed an optimizer bug in a C++ */ +	/* compiler, with symptom: 5**3 -> 25, when n=n+n was used] */ +	n=n<<1;			   /* move next bit to testable position */ +	if (n<0) {		   /* top bit is set */ +	  seenbit=1;		   /* OK, significant bit seen */ +	  decMultiplyOp(dac, dac, lhs, &aset, &status); /* dac=dac*x */ +	  } +	if (i==31) break;	   /* that was the last bit */ +	if (!seenbit) continue;	   /* no need to square 1 */ +	decMultiplyOp(dac, dac, dac, &aset, &status); /* dac=dac*dac [square] */ +	} /*i*/ /* 32 bits */ + +      /* complete internal overflow or underflow processing */ +      if (status & (DEC_Overflow|DEC_Underflow)) { +	#if DECSUBSET +	/* If subset, and power was negative, reverse the kind of -erflow */ +	/* [1/x not yet done] */ +	if (!set->extended && decNumberIsNegative(rhs)) { +	  if (status & DEC_Overflow) +	    status^=DEC_Overflow | DEC_Underflow | DEC_Subnormal; +	   else { /* trickier -- Underflow may or may not be set */ +	    status&=~(DEC_Underflow | DEC_Subnormal); /* [one or both] */ +	    status|=DEC_Overflow; +	    } +	  } +	#endif +	dac->bits=(dac->bits & ~DECNEG) | bits; /* force correct sign */ +	/* round subnormals [to set.digits rather than aset.digits] */ +	/* or set overflow result similarly as required */ +	decFinalize(dac, set, &residue, &status); +	decNumberCopy(res, dac);   /* copy to result (is now OK length) */ +	break; +	} + +      #if DECSUBSET +      if (!set->extended &&		     /* subset math */ +	  decNumberIsNegative(rhs)) {	     /* was a **-n [hence digits>0] */ +	/* so divide result into 1 [dac=1/dac] */ +	decDivideOp(dac, &dnOne, dac, &aset, DIVIDE, &status); +	} +      #endif +      } /* rhs integer path */ + +    /* reduce result to the requested length and copy to result */ +    decCopyFit(res, dac, set, &residue, &status); +    decFinish(res, set, &residue, &status);  /* final cleanup */ +    #if DECSUBSET +    if (!set->extended) decTrim(res, set, 0, &dropped); /* trailing zeros */ +    #endif +    } while(0);				/* end protected */ + +  if (allocdac!=NULL) free(allocdac);	/* drop any storage used */ +  if (allocinv!=NULL) free(allocinv);	/* .. */ +  #if DECSUBSET +  if (alloclhs!=NULL) free(alloclhs);	/* .. */ +  if (allocrhs!=NULL) free(allocrhs);	/* .. */ +  #endif +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberPower */ + +/* ------------------------------------------------------------------ */ +/* decNumberQuantize -- force exponent to requested value	      */ +/*								      */ +/*   This computes C = op(A, B), where op adjusts the coefficient     */ +/*   of C (by rounding or shifting) such that the exponent (-scale)   */ +/*   of C has exponent of B.  The numerical value of C will equal A,  */ +/*   except for the effects of any rounding that occurred.	      */ +/*								      */ +/*   res is C, the result.  C may be A or B			      */ +/*   lhs is A, the number to adjust				      */ +/*   rhs is B, the number with exponent to match		      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Unless there is an error or the result is infinite, the exponent   */ +/* after the operation is guaranteed to be equal to that of B.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberQuantize(decNumber *res, const decNumber *lhs, +			      const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decQuantizeOp(res, lhs, rhs, set, 1, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberQuantize */ + +/* ------------------------------------------------------------------ */ +/* decNumberReduce -- remove trailing zeros			      */ +/*								      */ +/*   This computes C = 0 + A, and normalizes the result		      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* Previously known as Normalize */ +decNumber * decNumberNormalize(decNumber *res, const decNumber *rhs, +			       decContext *set) { +  return decNumberReduce(res, rhs, set); +  } /* decNumberNormalize */ + +decNumber * decNumberReduce(decNumber *res, const decNumber *rhs, +			    decContext *set) { +  #if DECSUBSET +  decNumber *allocrhs=NULL;	   /* non-NULL if rounded rhs allocated */ +  #endif +  uInt status=0;		   /* as usual */ +  Int  residue=0;		   /* as usual */ +  Int  dropped;			   /* work */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operand and set lostDigits status, as needed */ +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* Infinities copy through; NaNs need usual treatment */ +    if (decNumberIsNaN(rhs)) { +      decNaNs(res, rhs, NULL, set, &status); +      break; +      } + +    /* reduce result to the requested length and copy to result */ +    decCopyFit(res, rhs, set, &residue, &status); /* copy & round */ +    decFinish(res, set, &residue, &status);	  /* cleanup/set flags */ +    decTrim(res, set, 1, &dropped);		  /* normalize in place */ +    } while(0);				     /* end protected */ + +  #if DECSUBSET +  if (allocrhs !=NULL) free(allocrhs);	     /* .. */ +  #endif +  if (status!=0) decStatus(res, status, set);/* then report status */ +  return res; +  } /* decNumberReduce */ + +/* ------------------------------------------------------------------ */ +/* decNumberRescale -- force exponent to requested value	      */ +/*								      */ +/*   This computes C = op(A, B), where op adjusts the coefficient     */ +/*   of C (by rounding or shifting) such that the exponent (-scale)   */ +/*   of C has the value B.  The numerical value of C will equal A,    */ +/*   except for the effects of any rounding that occurred.	      */ +/*								      */ +/*   res is C, the result.  C may be A or B			      */ +/*   lhs is A, the number to adjust				      */ +/*   rhs is B, the requested exponent				      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Unless there is an error or the result is infinite, the exponent   */ +/* after the operation is guaranteed to be equal to B.		      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberRescale(decNumber *res, const decNumber *lhs, +			     const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decQuantizeOp(res, lhs, rhs, set, 0, &status); +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberRescale */ + +/* ------------------------------------------------------------------ */ +/* decNumberRemainder -- divide and return remainder		      */ +/*								      */ +/*   This computes C = A % B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X%X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberRemainder(decNumber *res, const decNumber *lhs, +			       const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decDivideOp(res, lhs, rhs, set, REMAINDER, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberRemainder */ + +/* ------------------------------------------------------------------ */ +/* decNumberRemainderNear -- divide and return remainder from nearest */ +/*								      */ +/*   This computes C = A % B, where % is the IEEE remainder operator  */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X%X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberRemainderNear(decNumber *res, const decNumber *lhs, +				   const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ +  decDivideOp(res, lhs, rhs, set, REMNEAR, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberRemainderNear */ + +/* ------------------------------------------------------------------ */ +/* decNumberRotate -- rotate the coefficient of a Number left/right   */ +/*								      */ +/*   This computes C = A rot B	(in base ten and rotating set->digits */ +/*   digits).							      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=XrotX)	      */ +/*   lhs is A							      */ +/*   rhs is B, the number of digits to rotate (-ve to right)	      */ +/*   set is the context						      */ +/*								      */ +/* The digits of the coefficient of A are rotated to the left (if B   */ +/* is positive) or to the right (if B is negative) without adjusting  */ +/* the exponent or the sign of A.  If lhs->digits is less than	      */ +/* set->digits the coefficient is padded with zeros on the left	      */ +/* before the rotate.  Any leading zeros in the result are removed    */ +/* as usual.							      */ +/*								      */ +/* B must be an integer (q=0) and in the range -set->digits through   */ +/* +set->digits.						      */ +/* C must have space for set->digits digits.			      */ +/* NaNs are propagated as usual.  Infinities are unaffected (but      */ +/* B must be valid).  No status is set unless B is invalid or an      */ +/* operand is an sNaN.						      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberRotate(decNumber *res, const decNumber *lhs, +			   const decNumber *rhs, decContext *set) { +  uInt status=0;	      /* accumulator */ +  Int  rotate;		      /* rhs as an Int */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  /* NaNs propagate as normal */ +  if (decNumberIsNaN(lhs) || decNumberIsNaN(rhs)) +    decNaNs(res, lhs, rhs, set, &status); +   /* rhs must be an integer */ +   else if (decNumberIsInfinite(rhs) || rhs->exponent!=0) +    status=DEC_Invalid_operation; +   else { /* both numeric, rhs is an integer */ +    rotate=decGetInt(rhs);		     /* [cannot fail] */ +    if (rotate==BADINT			     /* something bad .. */ +     || rotate==BIGODD || rotate==BIGEVEN    /* .. very big .. */ +     || abs(rotate)>set->digits)	     /* .. or out of range */ +      status=DEC_Invalid_operation; +     else {				     /* rhs is OK */ +      decNumberCopy(res, lhs); +      /* convert -ve rotate to equivalent positive rotation */ +      if (rotate<0) rotate=set->digits+rotate; +      if (rotate!=0 && rotate!=set->digits   /* zero or full rotation */ +       && !decNumberIsInfinite(res)) {	     /* lhs was infinite */ +	/* left-rotate to do; 0 < rotate < set->digits */ +	uInt units, shift;		     /* work */ +	uInt msudigits;			     /* digits in result msu */ +	Unit *msu=res->lsu+D2U(res->digits)-1;	  /* current msu */ +	Unit *msumax=res->lsu+D2U(set->digits)-1; /* rotation msu */ +	for (msu++; msu<=msumax; msu++) *msu=0;	  /* ensure high units=0 */ +	res->digits=set->digits;		  /* now full-length */ +	msudigits=MSUDIGITS(res->digits);	  /* actual digits in msu */ + +	/* rotation here is done in-place, in three steps */ +	/* 1. shift all to least up to one unit to unit-align final */ +	/*    lsd [any digits shifted out are rotated to the left, */ +	/*    abutted to the original msd (which may require split)] */ +	/* */ +	/*    [if there are no whole units left to rotate, the */ +	/*    rotation is now complete] */ +	/* */ +	/* 2. shift to least, from below the split point only, so that */ +	/*    the final msd is in the right place in its Unit [any */ +	/*    digits shifted out will fit exactly in the current msu, */ +	/*    left aligned, no split required] */ +	/* */ +	/* 3. rotate all the units by reversing left part, right */ +	/*    part, and then whole */ +	/* */ +	/* example: rotate right 8 digits (2 units + 2), DECDPUN=3. */ +	/* */ +	/*   start: 00a bcd efg hij klm npq */ +	/* */ +	/*	1a  000 0ab cde fgh|ijk lmn [pq saved] */ +	/*	1b  00p qab cde fgh|ijk lmn */ +	/* */ +	/*	2a  00p qab cde fgh|00i jkl [mn saved] */ +	/*	2b  mnp qab cde fgh|00i jkl */ +	/* */ +	/*	3a  fgh cde qab mnp|00i jkl */ +	/*	3b  fgh cde qab mnp|jkl 00i */ +	/*	3c  00i jkl mnp qab cde fgh */ + +	/* Step 1: amount to shift is the partial right-rotate count */ +	rotate=set->digits-rotate;	/* make it right-rotate */ +	units=rotate/DECDPUN;		/* whole units to rotate */ +	shift=rotate%DECDPUN;		/* left-over digits count */ +	if (shift>0) {			/* not an exact number of units */ +	  uInt save=res->lsu[0]%powers[shift];	  /* save low digit(s) */ +	  decShiftToLeast(res->lsu, D2U(res->digits), shift); +	  if (shift>msudigits) {	/* msumax-1 needs >0 digits */ +	    uInt rem=save%powers[shift-msudigits];/* split save */ +	    *msumax=(Unit)(save/powers[shift-msudigits]); /* and insert */ +	    *(msumax-1)=*(msumax-1) +		       +(Unit)(rem*powers[DECDPUN-(shift-msudigits)]); /* .. */ +	    } +	   else { /* all fits in msumax */ +	    *msumax=*msumax+(Unit)(save*powers[msudigits-shift]); /* [maybe *1] */ +	    } +	  } /* digits shift needed */ + +	/* If whole units to rotate... */ +	if (units>0) {			/* some to do */ +	  /* Step 2: the units to touch are the whole ones in rotate, */ +	  /*   if any, and the shift is DECDPUN-msudigits (which may be */ +	  /*   0, again) */ +	  shift=DECDPUN-msudigits; +	  if (shift>0) {		/* not an exact number of units */ +	    uInt save=res->lsu[0]%powers[shift];  /* save low digit(s) */ +	    decShiftToLeast(res->lsu, units, shift); +	    *msumax=*msumax+(Unit)(save*powers[msudigits]); +	    } /* partial shift needed */ + +	  /* Step 3: rotate the units array using triple reverse */ +	  /* (reversing is easy and fast) */ +	  decReverse(res->lsu+units, msumax);	  /* left part */ +	  decReverse(res->lsu, res->lsu+units-1); /* right part */ +	  decReverse(res->lsu, msumax);		  /* whole */ +	  } /* whole units to rotate */ +	/* the rotation may have left an undetermined number of zeros */ +	/* on the left, so true length needs to be calculated */ +	res->digits=decGetDigits(res->lsu, msumax-res->lsu+1); +	} /* rotate needed */ +      } /* rhs OK */ +    } /* numerics */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberRotate */ + +/* ------------------------------------------------------------------ */ +/* decNumberSameQuantum -- test for equal exponents		      */ +/*								      */ +/*   res is the result number, which will contain either 0 or 1	      */ +/*   lhs is a number to test					      */ +/*   rhs is the second (usually a pattern)			      */ +/*								      */ +/* No errors are possible and no context is needed.		      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberSameQuantum(decNumber *res, const decNumber *lhs, +				 const decNumber *rhs) { +  Unit ret=0;			   /* return value */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, DECUNCONT)) return res; +  #endif + +  if (SPECIALARGS) { +    if (decNumberIsNaN(lhs) && decNumberIsNaN(rhs)) ret=1; +     else if (decNumberIsInfinite(lhs) && decNumberIsInfinite(rhs)) ret=1; +     /* [anything else with a special gives 0] */ +    } +   else if (lhs->exponent==rhs->exponent) ret=1; + +  decNumberZero(res);		   /* OK to overwrite an operand now */ +  *res->lsu=ret; +  return res; +  } /* decNumberSameQuantum */ + +/* ------------------------------------------------------------------ */ +/* decNumberScaleB -- multiply by a power of 10			      */ +/*								      */ +/* This computes C = A x 10**B where B is an integer (q=0) with	      */ +/* maximum magnitude 2*(emax+digits)				      */ +/*								      */ +/*   res is C, the result.  C may be A or B			      */ +/*   lhs is A, the number to adjust				      */ +/*   rhs is B, the requested power of ten to use		      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* The result may underflow or overflow.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberScaleB(decNumber *res, const decNumber *lhs, +			    const decNumber *rhs, decContext *set) { +  Int  reqexp;		      /* requested exponent change [B] */ +  uInt status=0;	      /* accumulator */ +  Int  residue;		      /* work */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  /* Handle special values except lhs infinite */ +  if (decNumberIsNaN(lhs) || decNumberIsNaN(rhs)) +    decNaNs(res, lhs, rhs, set, &status); +    /* rhs must be an integer */ +   else if (decNumberIsInfinite(rhs) || rhs->exponent!=0) +    status=DEC_Invalid_operation; +   else { +    /* lhs is a number; rhs is a finite with q==0 */ +    reqexp=decGetInt(rhs);		     /* [cannot fail] */ +    if (reqexp==BADINT			     /* something bad .. */ +     || reqexp==BIGODD || reqexp==BIGEVEN    /* .. very big .. */ +     || abs(reqexp)>(2*(set->digits+set->emax))) /* .. or out of range */ +      status=DEC_Invalid_operation; +     else {				     /* rhs is OK */ +      decNumberCopy(res, lhs);		     /* all done if infinite lhs */ +      if (!decNumberIsInfinite(res)) {	     /* prepare to scale */ +	res->exponent+=reqexp;		     /* adjust the exponent */ +	residue=0; +	decFinalize(res, set, &residue, &status); /* .. and check */ +	} /* finite LHS */ +      } /* rhs OK */ +    } /* rhs finite */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberScaleB */ + +/* ------------------------------------------------------------------ */ +/* decNumberShift -- shift the coefficient of a Number left or right  */ +/*								      */ +/*   This computes C = A << B or C = A >> -B  (in base ten).	      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X<<X)	      */ +/*   lhs is A							      */ +/*   rhs is B, the number of digits to shift (-ve to right)	      */ +/*   set is the context						      */ +/*								      */ +/* The digits of the coefficient of A are shifted to the left (if B   */ +/* is positive) or to the right (if B is negative) without adjusting  */ +/* the exponent or the sign of A.				      */ +/*								      */ +/* B must be an integer (q=0) and in the range -set->digits through   */ +/* +set->digits.						      */ +/* C must have space for set->digits digits.			      */ +/* NaNs are propagated as usual.  Infinities are unaffected (but      */ +/* B must be valid).  No status is set unless B is invalid or an      */ +/* operand is an sNaN.						      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberShift(decNumber *res, const decNumber *lhs, +			   const decNumber *rhs, decContext *set) { +  uInt status=0;	      /* accumulator */ +  Int  shift;		      /* rhs as an Int */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  /* NaNs propagate as normal */ +  if (decNumberIsNaN(lhs) || decNumberIsNaN(rhs)) +    decNaNs(res, lhs, rhs, set, &status); +   /* rhs must be an integer */ +   else if (decNumberIsInfinite(rhs) || rhs->exponent!=0) +    status=DEC_Invalid_operation; +   else { /* both numeric, rhs is an integer */ +    shift=decGetInt(rhs);		     /* [cannot fail] */ +    if (shift==BADINT			     /* something bad .. */ +     || shift==BIGODD || shift==BIGEVEN	     /* .. very big .. */ +     || abs(shift)>set->digits)		     /* .. or out of range */ +      status=DEC_Invalid_operation; +     else {				     /* rhs is OK */ +      decNumberCopy(res, lhs); +      if (shift!=0 && !decNumberIsInfinite(res)) { /* something to do */ +	if (shift>0) {			     /* to left */ +	  if (shift==set->digits) {	     /* removing all */ +	    *res->lsu=0;		     /* so place 0 */ +	    res->digits=1;		     /* .. */ +	    } +	   else {			     /* */ +	    /* first remove leading digits if necessary */ +	    if (res->digits+shift>set->digits) { +	      decDecap(res, res->digits+shift-set->digits); +	      /* that updated res->digits; may have gone to 1 (for a */ +	      /* single digit or for zero */ +	      } +	    if (res->digits>1 || *res->lsu)  /* if non-zero.. */ +	      res->digits=decShiftToMost(res->lsu, res->digits, shift); +	    } /* partial left */ +	  } /* left */ +	 else { /* to right */ +	  if (-shift>=res->digits) {	     /* discarding all */ +	    *res->lsu=0;		     /* so place 0 */ +	    res->digits=1;		     /* .. */ +	    } +	   else { +	    decShiftToLeast(res->lsu, D2U(res->digits), -shift); +	    res->digits-=(-shift); +	    } +	  } /* to right */ +	} /* non-0 non-Inf shift */ +      } /* rhs OK */ +    } /* numerics */ +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberShift */ + +/* ------------------------------------------------------------------ */ +/* decNumberSquareRoot -- square root operator			      */ +/*								      */ +/*   This computes C = squareroot(A)				      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +/* This uses the following varying-precision algorithm in:	      */ +/*								      */ +/*   Properly Rounded Variable Precision Square Root, T. E. Hull and  */ +/*   A. Abrham, ACM Transactions on Mathematical Software, Vol 11 #3, */ +/*   pp229-237, ACM, September 1985.				      */ +/*								      */ +/* The square-root is calculated using Newton's method, after which   */ +/* a check is made to ensure the result is correctly rounded.	      */ +/*								      */ +/* % [Reformatted original Numerical Turing source code follows.]     */ +/* function sqrt(x : real) : real				      */ +/* % sqrt(x) returns the properly rounded approximation to the square */ +/* % root of x, in the precision of the calling environment, or it    */ +/* % fails if x < 0.						      */ +/* % t e hull and a abrham, august, 1984			      */ +/* if x <= 0 then						      */ +/*   if x < 0 then						      */ +/*     assert false						      */ +/*   else							      */ +/*     result 0							      */ +/*   end if							      */ +/* end if							      */ +/* var f := setexp(x, 0)  % fraction part of x	 [0.1 <= x < 1]	      */ +/* var e := getexp(x)	  % exponent part of x			      */ +/* var approx : real						      */ +/* if e mod 2 = 0  then						      */ +/*   approx := .259 + .819 * f	 % approx to root of f		      */ +/* else								      */ +/*   f := f/l0			 % adjustments			      */ +/*   e := e + 1			 %   for odd			      */ +/*   approx := .0819 + 2.59 * f	 %   exponent			      */ +/* end if							      */ +/*								      */ +/* var p:= 3							      */ +/* const maxp := currentprecision + 2				      */ +/* loop								      */ +/*   p := min(2*p - 2, maxp)	 % p = 4,6,10, . . . , maxp	      */ +/*   precision p						      */ +/*   approx := .5 * (approx + f/approx)				      */ +/*   exit when p = maxp						      */ +/* end loop							      */ +/*								      */ +/* % approx is now within 1 ulp of the properly rounded square root   */ +/* % of f; to ensure proper rounding, compare squares of (approx -    */ +/* % l/2 ulp) and (approx + l/2 ulp) with f.			      */ +/* p := currentprecision					      */ +/* begin							      */ +/*   precision p + 2						      */ +/*   const approxsubhalf := approx - setexp(.5, -p)		      */ +/*   if mulru(approxsubhalf, approxsubhalf) > f then		      */ +/*     approx := approx - setexp(.l, -p + 1)			      */ +/*   else							      */ +/*     const approxaddhalf := approx + setexp(.5, -p)		      */ +/*     if mulrd(approxaddhalf, approxaddhalf) < f then		      */ +/*	 approx := approx + setexp(.l, -p + 1)			      */ +/*     end if							      */ +/*   end if							      */ +/* end								      */ +/* result setexp(approx, e div 2)  % fix exponent		      */ +/* end sqrt							      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberSquareRoot(decNumber *res, const decNumber *rhs, +				decContext *set) { +  decContext workset, approxset;   /* work contexts */ +  decNumber dzero;		   /* used for constant zero */ +  Int  maxp;			   /* largest working precision */ +  Int  workp;			   /* working precision */ +  Int  residue=0;		   /* rounding residue */ +  uInt status=0, ignore=0;	   /* status accumulators */ +  uInt rstatus;			   /* .. */ +  Int  exp;			   /* working exponent */ +  Int  ideal;			   /* ideal (preferred) exponent */ +  Int  needbytes;		   /* work */ +  Int  dropped;			   /* .. */ + +  #if DECSUBSET +  decNumber *allocrhs=NULL;	   /* non-NULL if rounded rhs allocated */ +  #endif +  /* buffer for f [needs +1 in case DECBUFFER 0] */ +  decNumber buff[D2N(DECBUFFER+1)]; +  /* buffer for a [needs +2 to match likely maxp] */ +  decNumber bufa[D2N(DECBUFFER+2)]; +  /* buffer for temporary, b [must be same size as a] */ +  decNumber bufb[D2N(DECBUFFER+2)]; +  decNumber *allocbuff=NULL;	   /* -> allocated buff, iff allocated */ +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *allocbufb=NULL;	   /* -> allocated bufb, iff allocated */ +  decNumber *f=buff;		   /* reduced fraction */ +  decNumber *a=bufa;		   /* approximation to result */ +  decNumber *b=bufb;		   /* intermediate result */ +  /* buffer for temporary variable, up to 3 digits */ +  decNumber buft[D2N(3)]; +  decNumber *t=buft;		   /* up-to-3-digit constant or work */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operand and set lostDigits status, as needed */ +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, &status); +	if (allocrhs==NULL) break; +	/* [Note: 'f' allocation below could reuse this buffer if */ +	/* used, but as this is rare they are kept separate for clarity.] */ +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* handle infinities and NaNs */ +    if (SPECIALARG) { +      if (decNumberIsInfinite(rhs)) {	      /* an infinity */ +	if (decNumberIsNegative(rhs)) status|=DEC_Invalid_operation; +	 else decNumberCopy(res, rhs);	      /* +Infinity */ +	} +       else decNaNs(res, rhs, NULL, set, &status); /* a NaN */ +      break; +      } + +    /* calculate the ideal (preferred) exponent [floor(exp/2)] */ +    /* [We would like to write: ideal=rhs->exponent>>1, but this */ +    /* generates a compiler warning.  Generated code is the same.] */ +    ideal=(rhs->exponent&~1)/2;		/* target */ + +    /* handle zeros */ +    if (ISZERO(rhs)) { +      decNumberCopy(res, rhs);		/* could be 0 or -0 */ +      res->exponent=ideal;		/* use the ideal [safe] */ +      /* use decFinish to clamp any out-of-range exponent, etc. */ +      decFinish(res, set, &residue, &status); +      break; +      } + +    /* any other -x is an oops */ +    if (decNumberIsNegative(rhs)) { +      status|=DEC_Invalid_operation; +      break; +      } + +    /* space is needed for three working variables */ +    /*	 f -- the same precision as the RHS, reduced to 0.01->0.99... */ +    /*	 a -- Hull's approximation -- precision, when assigned, is */ +    /*	      currentprecision+1 or the input argument precision, */ +    /*	      whichever is larger (+2 for use as temporary) */ +    /*	 b -- intermediate temporary result (same size as a) */ +    /* if any is too long for local storage, then allocate */ +    workp=MAXI(set->digits+1, rhs->digits);  /* actual rounding precision */ +    maxp=workp+2;			     /* largest working precision */ + +    needbytes=sizeof(decNumber)+(D2U(rhs->digits)-1)*sizeof(Unit); +    if (needbytes>(Int)sizeof(buff)) { +      allocbuff=(decNumber *)malloc(needbytes); +      if (allocbuff==NULL) {  /* hopeless -- abandon */ +	status|=DEC_Insufficient_storage; +	break;} +      f=allocbuff;	      /* use the allocated space */ +      } +    /* a and b both need to be able to hold a maxp-length number */ +    needbytes=sizeof(decNumber)+(D2U(maxp)-1)*sizeof(Unit); +    if (needbytes>(Int)sizeof(bufa)) {		  /* [same applies to b] */ +      allocbufa=(decNumber *)malloc(needbytes); +      allocbufb=(decNumber *)malloc(needbytes); +      if (allocbufa==NULL || allocbufb==NULL) {	  /* hopeless */ +	status|=DEC_Insufficient_storage; +	break;} +      a=allocbufa;	      /* use the allocated spaces */ +      b=allocbufb;	      /* .. */ +      } + +    /* copy rhs -> f, save exponent, and reduce so 0.1 <= f < 1 */ +    decNumberCopy(f, rhs); +    exp=f->exponent+f->digits;		     /* adjusted to Hull rules */ +    f->exponent=-(f->digits);		     /* to range */ + +    /* set up working context */ +    decContextDefault(&workset, DEC_INIT_DECIMAL64); + +    /* [Until further notice, no error is possible and status bits */ +    /* (Rounded, etc.) should be ignored, not accumulated.] */ + +    /* Calculate initial approximation, and allow for odd exponent */ +    workset.digits=workp;		     /* p for initial calculation */ +    t->bits=0; t->digits=3; +    a->bits=0; a->digits=3; +    if ((exp & 1)==0) {			     /* even exponent */ +      /* Set t=0.259, a=0.819 */ +      t->exponent=-3; +      a->exponent=-3; +      #if DECDPUN>=3 +	t->lsu[0]=259; +	a->lsu[0]=819; +      #elif DECDPUN==2 +	t->lsu[0]=59; t->lsu[1]=2; +	a->lsu[0]=19; a->lsu[1]=8; +      #else +	t->lsu[0]=9; t->lsu[1]=5; t->lsu[2]=2; +	a->lsu[0]=9; a->lsu[1]=1; a->lsu[2]=8; +      #endif +      } +     else {				     /* odd exponent */ +      /* Set t=0.0819, a=2.59 */ +      f->exponent--;			     /* f=f/10 */ +      exp++;				     /* e=e+1 */ +      t->exponent=-4; +      a->exponent=-2; +      #if DECDPUN>=3 +	t->lsu[0]=819; +	a->lsu[0]=259; +      #elif DECDPUN==2 +	t->lsu[0]=19; t->lsu[1]=8; +	a->lsu[0]=59; a->lsu[1]=2; +      #else +	t->lsu[0]=9; t->lsu[1]=1; t->lsu[2]=8; +	a->lsu[0]=9; a->lsu[1]=5; a->lsu[2]=2; +      #endif +      } +    decMultiplyOp(a, a, f, &workset, &ignore);	  /* a=a*f */ +    decAddOp(a, a, t, &workset, 0, &ignore);	  /* ..+t */ +    /* [a is now the initial approximation for sqrt(f), calculated with */ +    /* currentprecision, which is also a's precision.] */ + +    /* the main calculation loop */ +    decNumberZero(&dzero);		     /* make 0 */ +    decNumberZero(t);			     /* set t = 0.5 */ +    t->lsu[0]=5;			     /* .. */ +    t->exponent=-1;			     /* .. */ +    workset.digits=3;			     /* initial p */ +    for (;;) { +      /* set p to min(2*p - 2, maxp)  [hence 3; or: 4, 6, 10, ... , maxp] */ +      workset.digits=workset.digits*2-2; +      if (workset.digits>maxp) workset.digits=maxp; +      /* a = 0.5 * (a + f/a) */ +      /* [calculated at p then rounded to currentprecision] */ +      decDivideOp(b, f, a, &workset, DIVIDE, &ignore); /* b=f/a */ +      decAddOp(b, b, a, &workset, 0, &ignore);	  /* b=b+a */ +      decMultiplyOp(a, b, t, &workset, &ignore);  /* a=b*0.5 */ +      if (a->digits==maxp) break;	     /* have required digits */ +      } /* loop */ + +    /* Here, 0.1 <= a < 1 [Hull], and a has maxp digits */ +    /* now reduce to length, etc.; this needs to be done with a */ +    /* having the correct exponent so as to handle subnormals */ +    /* correctly */ +    approxset=*set;			     /* get emin, emax, etc. */ +    approxset.round=DEC_ROUND_HALF_EVEN; +    a->exponent+=exp/2;			     /* set correct exponent */ + +    rstatus=0;				     /* clear status */ +    residue=0;				     /* .. and accumulator */ +    decCopyFit(a, a, &approxset, &residue, &rstatus);  /* reduce (if needed) */ +    decFinish(a, &approxset, &residue, &rstatus);      /* clean and finalize */ + +    /* Overflow was possible if the input exponent was out-of-range, */ +    /* in which case quit */ +    if (rstatus&DEC_Overflow) { +      status=rstatus;			     /* use the status as-is */ +      decNumberCopy(res, a);		     /* copy to result */ +      break; +      } + +    /* Preserve status except Inexact/Rounded */ +    status|=(rstatus & ~(DEC_Rounded|DEC_Inexact)); + +    /* Carry out the Hull correction */ +    a->exponent-=exp/2;			     /* back to 0.1->1 */ + +    /* a is now at final precision and within 1 ulp of the properly */ +    /* rounded square root of f; to ensure proper rounding, compare */ +    /* squares of (a - l/2 ulp) and (a + l/2 ulp) with f. */ +    /* Here workset.digits=maxp and t=0.5, and a->digits determines */ +    /* the ulp */ +    workset.digits--;				  /* maxp-1 is OK now */ +    t->exponent=-a->digits-1;			  /* make 0.5 ulp */ +    decAddOp(b, a, t, &workset, DECNEG, &ignore); /* b = a - 0.5 ulp */ +    workset.round=DEC_ROUND_UP; +    decMultiplyOp(b, b, b, &workset, &ignore);	  /* b = mulru(b, b) */ +    decCompareOp(b, f, b, &workset, COMPARE, &ignore); /* b ? f, reversed */ +    if (decNumberIsNegative(b)) {		  /* f < b [i.e., b > f] */ +      /* this is the more common adjustment, though both are rare */ +      t->exponent++;				  /* make 1.0 ulp */ +      t->lsu[0]=1;				  /* .. */ +      decAddOp(a, a, t, &workset, DECNEG, &ignore); /* a = a - 1 ulp */ +      /* assign to approx [round to length] */ +      approxset.emin-=exp/2;			  /* adjust to match a */ +      approxset.emax-=exp/2; +      decAddOp(a, &dzero, a, &approxset, 0, &ignore); +      } +     else { +      decAddOp(b, a, t, &workset, 0, &ignore);	  /* b = a + 0.5 ulp */ +      workset.round=DEC_ROUND_DOWN; +      decMultiplyOp(b, b, b, &workset, &ignore);  /* b = mulrd(b, b) */ +      decCompareOp(b, b, f, &workset, COMPARE, &ignore);   /* b ? f */ +      if (decNumberIsNegative(b)) {		  /* b < f */ +	t->exponent++;				  /* make 1.0 ulp */ +	t->lsu[0]=1;				  /* .. */ +	decAddOp(a, a, t, &workset, 0, &ignore);  /* a = a + 1 ulp */ +	/* assign to approx [round to length] */ +	approxset.emin-=exp/2;			  /* adjust to match a */ +	approxset.emax-=exp/2; +	decAddOp(a, &dzero, a, &approxset, 0, &ignore); +	} +      } +    /* [no errors are possible in the above, and rounding/inexact during */ +    /* estimation are irrelevant, so status was not accumulated] */ + +    /* Here, 0.1 <= a < 1  (still), so adjust back */ +    a->exponent+=exp/2;			     /* set correct exponent */ + +    /* count droppable zeros [after any subnormal rounding] by */ +    /* trimming a copy */ +    decNumberCopy(b, a); +    decTrim(b, set, 1, &dropped);	     /* [drops trailing zeros] */ + +    /* Set Inexact and Rounded.	 The answer can only be exact if */ +    /* it is short enough so that squaring it could fit in workp digits, */ +    /* and it cannot have trailing zeros due to clamping, so these are */ +    /* the only (relatively rare) conditions a careful check is needed */ +    if (b->digits*2-1 > workp && !set->clamp) { /* cannot fit */ +      status|=DEC_Inexact|DEC_Rounded; +      } +     else {				     /* could be exact/unrounded */ +      uInt mstatus=0;			     /* local status */ +      decMultiplyOp(b, b, b, &workset, &mstatus); /* try the multiply */ +      if (mstatus&DEC_Overflow) {	     /* result just won't fit */ +	status|=DEC_Inexact|DEC_Rounded; +	} +       else {				     /* plausible */ +	decCompareOp(t, b, rhs, &workset, COMPARE, &mstatus); /* b ? rhs */ +	if (!ISZERO(t)) status|=DEC_Inexact|DEC_Rounded; /* not equal */ +	 else {				     /* is Exact */ +	  /* here, dropped is the count of trailing zeros in 'a' */ +	  /* use closest exponent to ideal... */ +	  Int todrop=ideal-a->exponent;	     /* most that can be dropped */ +	  if (todrop<0) status|=DEC_Rounded; /* ideally would add 0s */ +	   else {			     /* unrounded */ +	    if (dropped<todrop) {	     /* clamp to those available */ +	      todrop=dropped; +	      status|=DEC_Clamped; +	      } +	    if (todrop>0) {		     /* have some to drop */ +	      decShiftToLeast(a->lsu, D2U(a->digits), todrop); +	      a->exponent+=todrop;	     /* maintain numerical value */ +	      a->digits-=todrop;	     /* new length */ +	      } +	    } +	  } +	} +      } + +    /* double-check Underflow, as perhaps the result could not have */ +    /* been subnormal (initial argument too big), or it is now Exact */ +    if (status&DEC_Underflow) { +      Int ae=rhs->exponent+rhs->digits-1;    /* adjusted exponent */ +      /* check if truly subnormal */ +      #if DECEXTFLAG			     /* DEC_Subnormal too */ +	if (ae>=set->emin*2) status&=~(DEC_Subnormal|DEC_Underflow); +      #else +	if (ae>=set->emin*2) status&=~DEC_Underflow; +      #endif +      /* check if truly inexact */ +      if (!(status&DEC_Inexact)) status&=~DEC_Underflow; +      } + +    decNumberCopy(res, a);		     /* a is now the result */ +    } while(0);				     /* end protected */ + +  if (allocbuff!=NULL) free(allocbuff);	     /* drop any storage used */ +  if (allocbufa!=NULL) free(allocbufa);	     /* .. */ +  if (allocbufb!=NULL) free(allocbufb);	     /* .. */ +  #if DECSUBSET +  if (allocrhs !=NULL) free(allocrhs);	     /* .. */ +  #endif +  if (status!=0) decStatus(res, status, set);/* then report status */ +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberSquareRoot */ + +/* ------------------------------------------------------------------ */ +/* decNumberSubtract -- subtract two Numbers			      */ +/*								      */ +/*   This computes C = A - B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X-X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberSubtract(decNumber *res, const decNumber *lhs, +			      const decNumber *rhs, decContext *set) { +  uInt status=0;			/* accumulator */ + +  decAddOp(res, lhs, rhs, set, DECNEG, &status); +  if (status!=0) decStatus(res, status, set); +  #if DECCHECK +  decCheckInexact(res, set); +  #endif +  return res; +  } /* decNumberSubtract */ + +/* ------------------------------------------------------------------ */ +/* decNumberToIntegralExact -- round-to-integral-value with InExact   */ +/* decNumberToIntegralValue -- round-to-integral-value		      */ +/*								      */ +/*   res is the result						      */ +/*   rhs is input number					      */ +/*   set is the context						      */ +/*								      */ +/* res must have space for any value of rhs.			      */ +/*								      */ +/* This implements the IEEE special operators and therefore treats    */ +/* special values as valid.  For finite numbers it returns	      */ +/* rescale(rhs, 0) if rhs->exponent is <0.			      */ +/* Otherwise the result is rhs (so no error is possible, except for   */ +/* sNaN).							      */ +/*								      */ +/* The context is used for rounding mode and status after sNaN, but   */ +/* the digits setting is ignored.  The Exact version will signal      */ +/* Inexact if the result differs numerically from rhs; the other      */ +/* never signals Inexact.					      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberToIntegralExact(decNumber *res, const decNumber *rhs, +				     decContext *set) { +  decNumber dn; +  decContext workset;		   /* working context */ +  uInt status=0;		   /* accumulator */ + +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  /* handle infinities and NaNs */ +  if (SPECIALARG) { +    if (decNumberIsInfinite(rhs)) decNumberCopy(res, rhs); /* an Infinity */ +     else decNaNs(res, rhs, NULL, set, &status); /* a NaN */ +    } +   else { /* finite */ +    /* have a finite number; no error possible (res must be big enough) */ +    if (rhs->exponent>=0) return decNumberCopy(res, rhs); +    /* that was easy, but if negative exponent there is work to do... */ +    workset=*set;		   /* clone rounding, etc. */ +    workset.digits=rhs->digits;	   /* no length rounding */ +    workset.traps=0;		   /* no traps */ +    decNumberZero(&dn);		   /* make a number with exponent 0 */ +    decNumberQuantize(res, rhs, &dn, &workset); +    status|=workset.status; +    } +  if (status!=0) decStatus(res, status, set); +  return res; +  } /* decNumberToIntegralExact */ + +decNumber * decNumberToIntegralValue(decNumber *res, const decNumber *rhs, +				     decContext *set) { +  decContext workset=*set;	   /* working context */ +  workset.traps=0;		   /* no traps */ +  decNumberToIntegralExact(res, rhs, &workset); +  /* this never affects set, except for sNaNs; NaN will have been set */ +  /* or propagated already, so no need to call decStatus */ +  set->status|=workset.status&DEC_Invalid_operation; +  return res; +  } /* decNumberToIntegralValue */ + +/* ------------------------------------------------------------------ */ +/* decNumberXor -- XOR two Numbers, digitwise			      */ +/*								      */ +/*   This computes C = A ^ B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X^X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context (used for result length and error report)     */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Logical function restrictions apply (see above); a NaN is	      */ +/* returned with Invalid_operation if a restriction is violated.      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberXor(decNumber *res, const decNumber *lhs, +			 const decNumber *rhs, decContext *set) { +  const Unit *ua, *ub;			/* -> operands */ +  const Unit *msua, *msub;		/* -> operand msus */ +  Unit	*uc, *msuc;			/* -> result and its msu */ +  Int	msudigs;			/* digits in res msu */ +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  if (lhs->exponent!=0 || decNumberIsSpecial(lhs) || decNumberIsNegative(lhs) +   || rhs->exponent!=0 || decNumberIsSpecial(rhs) || decNumberIsNegative(rhs)) { +    decStatus(res, DEC_Invalid_operation, set); +    return res; +    } +  /* operands are valid */ +  ua=lhs->lsu;				/* bottom-up */ +  ub=rhs->lsu;				/* .. */ +  uc=res->lsu;				/* .. */ +  msua=ua+D2U(lhs->digits)-1;		/* -> msu of lhs */ +  msub=ub+D2U(rhs->digits)-1;		/* -> msu of rhs */ +  msuc=uc+D2U(set->digits)-1;		/* -> msu of result */ +  msudigs=MSUDIGITS(set->digits);	/* [faster than remainder] */ +  for (; uc<=msuc; ua++, ub++, uc++) {	/* Unit loop */ +    Unit a, b;				/* extract units */ +    if (ua>msua) a=0; +     else a=*ua; +    if (ub>msub) b=0; +     else b=*ub; +    *uc=0;				/* can now write back */ +    if (a|b) {				/* maybe 1 bits to examine */ +      Int i, j; +      /* This loop could be unrolled and/or use BIN2BCD tables */ +      for (i=0; i<DECDPUN; i++) { +	if ((a^b)&1) *uc=*uc+(Unit)powers[i];	  /* effect XOR */ +	j=a%10; +	a=a/10; +	j|=b%10; +	b=b/10; +	if (j>1) { +	  decStatus(res, DEC_Invalid_operation, set); +	  return res; +	  } +	if (uc==msuc && i==msudigs-1) break;	  /* just did final digit */ +	} /* each digit */ +      } /* non-zero */ +    } /* each unit */ +  /* [here uc-1 is the msu of the result] */ +  res->digits=decGetDigits(res->lsu, uc-res->lsu); +  res->exponent=0;			/* integer */ +  res->bits=0;				/* sign=0 */ +  return res;  /* [no status to set] */ +  } /* decNumberXor */ + + +/* ================================================================== */ +/* Utility routines						      */ +/* ================================================================== */ + +/* ------------------------------------------------------------------ */ +/* decNumberClass -- return the decClass of a decNumber		      */ +/*   dn -- the decNumber to test				      */ +/*   set -- the context to use for Emin				      */ +/*   returns the decClass enum					      */ +/* ------------------------------------------------------------------ */ +enum decClass decNumberClass(const decNumber *dn, decContext *set) { +  if (decNumberIsSpecial(dn)) { +    if (decNumberIsQNaN(dn)) return DEC_CLASS_QNAN; +    if (decNumberIsSNaN(dn)) return DEC_CLASS_SNAN; +    /* must be an infinity */ +    if (decNumberIsNegative(dn)) return DEC_CLASS_NEG_INF; +    return DEC_CLASS_POS_INF; +    } +  /* is finite */ +  if (decNumberIsNormal(dn, set)) { /* most common */ +    if (decNumberIsNegative(dn)) return DEC_CLASS_NEG_NORMAL; +    return DEC_CLASS_POS_NORMAL; +    } +  /* is subnormal or zero */ +  if (decNumberIsZero(dn)) {	/* most common */ +    if (decNumberIsNegative(dn)) return DEC_CLASS_NEG_ZERO; +    return DEC_CLASS_POS_ZERO; +    } +  if (decNumberIsNegative(dn)) return DEC_CLASS_NEG_SUBNORMAL; +  return DEC_CLASS_POS_SUBNORMAL; +  } /* decNumberClass */ + +/* ------------------------------------------------------------------ */ +/* decNumberClassToString -- convert decClass to a string	      */ +/*								      */ +/*  eclass is a valid decClass					      */ +/*  returns a constant string describing the class (max 13+1 chars)   */ +/* ------------------------------------------------------------------ */ +const char *decNumberClassToString(enum decClass eclass) { +  if (eclass==DEC_CLASS_POS_NORMAL)    return DEC_ClassString_PN; +  if (eclass==DEC_CLASS_NEG_NORMAL)    return DEC_ClassString_NN; +  if (eclass==DEC_CLASS_POS_ZERO)      return DEC_ClassString_PZ; +  if (eclass==DEC_CLASS_NEG_ZERO)      return DEC_ClassString_NZ; +  if (eclass==DEC_CLASS_POS_SUBNORMAL) return DEC_ClassString_PS; +  if (eclass==DEC_CLASS_NEG_SUBNORMAL) return DEC_ClassString_NS; +  if (eclass==DEC_CLASS_POS_INF)       return DEC_ClassString_PI; +  if (eclass==DEC_CLASS_NEG_INF)       return DEC_ClassString_NI; +  if (eclass==DEC_CLASS_QNAN)	       return DEC_ClassString_QN; +  if (eclass==DEC_CLASS_SNAN)	       return DEC_ClassString_SN; +  return DEC_ClassString_UN;	       /* Unknown */ +  } /* decNumberClassToString */ + +/* ------------------------------------------------------------------ */ +/* decNumberCopy -- copy a number				      */ +/*								      */ +/*   dest is the target decNumber				      */ +/*   src  is the source decNumber				      */ +/*   returns dest						      */ +/*								      */ +/* (dest==src is allowed and is a no-op)			      */ +/* All fields are updated as required.	This is a utility operation,  */ +/* so special values are unchanged and no error is possible.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCopy(decNumber *dest, const decNumber *src) { + +  #if DECCHECK +  if (src==NULL) return decNumberZero(dest); +  #endif + +  if (dest==src) return dest;		     /* no copy required */ + +  /* Use explicit assignments here as structure assignment could copy */ +  /* more than just the lsu (for small DECDPUN).  This would not affect */ +  /* the value of the results, but could disturb test harness spill */ +  /* checking. */ +  dest->bits=src->bits; +  dest->exponent=src->exponent; +  dest->digits=src->digits; +  dest->lsu[0]=src->lsu[0]; +  if (src->digits>DECDPUN) {		     /* more Units to come */ +    const Unit *smsup, *s;		     /* work */ +    Unit  *d;				     /* .. */ +    /* memcpy for the remaining Units would be safe as they cannot */ +    /* overlap.	 However, this explicit loop is faster in short cases. */ +    d=dest->lsu+1;			     /* -> first destination */ +    smsup=src->lsu+D2U(src->digits);	     /* -> source msu+1 */ +    for (s=src->lsu+1; s<smsup; s++, d++) *d=*s; +    } +  return dest; +  } /* decNumberCopy */ + +/* ------------------------------------------------------------------ */ +/* decNumberCopyAbs -- quiet absolute value operator		      */ +/*								      */ +/*   This sets C = abs(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* No exception or error can occur; this is a quiet bitwise operation.*/ +/* See also decNumberAbs for a checking version of this.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCopyAbs(decNumber *res, const decNumber *rhs) { +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, DECUNCONT)) return res; +  #endif +  decNumberCopy(res, rhs); +  res->bits&=~DECNEG;			/* turn off sign */ +  return res; +  } /* decNumberCopyAbs */ + +/* ------------------------------------------------------------------ */ +/* decNumberCopyNegate -- quiet negate value operator		      */ +/*								      */ +/*   This sets C = negate(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* No exception or error can occur; this is a quiet bitwise operation.*/ +/* See also decNumberMinus for a checking version of this.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCopyNegate(decNumber *res, const decNumber *rhs) { +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, DECUNCONT)) return res; +  #endif +  decNumberCopy(res, rhs); +  res->bits^=DECNEG;			/* invert the sign */ +  return res; +  } /* decNumberCopyNegate */ + +/* ------------------------------------------------------------------ */ +/* decNumberCopySign -- quiet copy and set sign operator	      */ +/*								      */ +/*   This sets C = A with the sign of B				      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* No exception or error can occur; this is a quiet bitwise operation.*/ +/* ------------------------------------------------------------------ */ +decNumber * decNumberCopySign(decNumber *res, const decNumber *lhs, +			      const decNumber *rhs) { +  uByte sign;				/* rhs sign */ +  #if DECCHECK +  if (decCheckOperands(res, DECUNUSED, rhs, DECUNCONT)) return res; +  #endif +  sign=rhs->bits & DECNEG;		/* save sign bit */ +  decNumberCopy(res, lhs); +  res->bits&=~DECNEG;			/* clear the sign */ +  res->bits|=sign;			/* set from rhs */ +  return res; +  } /* decNumberCopySign */ + +/* ------------------------------------------------------------------ */ +/* decNumberGetBCD -- get the coefficient in BCD8		      */ +/*   dn is the source decNumber					      */ +/*   bcd is the uInt array that will receive dn->digits BCD bytes,    */ +/*     most-significant at offset 0				      */ +/*   returns bcd						      */ +/*								      */ +/* bcd must have at least dn->digits bytes.  No error is possible; if */ +/* dn is a NaN or Infinite, digits must be 1 and the coefficient 0.   */ +/* ------------------------------------------------------------------ */ +uByte * decNumberGetBCD(const decNumber *dn, uint8_t *bcd) { +  uByte *ub=bcd+dn->digits-1;	   /* -> lsd */ +  const Unit *up=dn->lsu;	   /* Unit pointer, -> lsu */ + +  #if DECDPUN==1		   /* trivial simple copy */ +    for (; ub>=bcd; ub--, up++) *ub=*up; +  #else				   /* chopping needed */ +    uInt u=*up;			   /* work */ +    uInt cut=DECDPUN;		   /* downcounter through unit */ +    for (; ub>=bcd; ub--) { +      *ub=(uByte)(u%10);	   /* [*6554 trick inhibits, here] */ +      u=u/10; +      cut--; +      if (cut>0) continue;	   /* more in this unit */ +      up++; +      u=*up; +      cut=DECDPUN; +      } +  #endif +  return bcd; +  } /* decNumberGetBCD */ + +/* ------------------------------------------------------------------ */ +/* decNumberSetBCD -- set (replace) the coefficient from BCD8	      */ +/*   dn is the target decNumber					      */ +/*   bcd is the uInt array that will source n BCD bytes, most-	      */ +/*     significant at offset 0					      */ +/*   n is the number of digits in the source BCD array (bcd)	      */ +/*   returns dn							      */ +/*								      */ +/* dn must have space for at least n digits.  No error is possible;   */ +/* if dn is a NaN, or Infinite, or is to become a zero, n must be 1   */ +/* and bcd[0] zero.						      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberSetBCD(decNumber *dn, const uByte *bcd, uInt n) { +  Unit *up = dn->lsu + D2U(n) - 1;      /* -> msu [target pointer] */ +  const uByte *ub=bcd;			/* -> source msd */ + +  #if DECDPUN==1			/* trivial simple copy */ +    for (; ub<bcd+n; ub++, up--) *up=*ub; +  #else					/* some assembly needed */ +    /* calculate how many digits in msu, and hence first cut */ +    Int cut=MSUDIGITS(n);		/* [faster than remainder] */ +    for (;up>=dn->lsu; up--) {		/* each Unit from msu */ +      *up=0;				/* will take <=DECDPUN digits */ +      for (; cut>0; ub++, cut--) *up=X10(*up)+*ub; +      cut=DECDPUN;			/* next Unit has all digits */ +      } +  #endif +  dn->digits=n;				/* set digit count */ +  return dn; +  } /* decNumberSetBCD */ + +/* ------------------------------------------------------------------ */ +/* decNumberIsNormal -- test normality of a decNumber		      */ +/*   dn is the decNumber to test				      */ +/*   set is the context to use for Emin				      */ +/*   returns 1 if |dn| is finite and >=Nmin, 0 otherwise	      */ +/* ------------------------------------------------------------------ */ +Int decNumberIsNormal(const decNumber *dn, decContext *set) { +  Int ae;				/* adjusted exponent */ +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, dn, set)) return 0; +  #endif + +  if (decNumberIsSpecial(dn)) return 0; /* not finite */ +  if (decNumberIsZero(dn)) return 0;	/* not non-zero */ + +  ae=dn->exponent+dn->digits-1;		/* adjusted exponent */ +  if (ae<set->emin) return 0;		/* is subnormal */ +  return 1; +  } /* decNumberIsNormal */ + +/* ------------------------------------------------------------------ */ +/* decNumberIsSubnormal -- test subnormality of a decNumber	      */ +/*   dn is the decNumber to test				      */ +/*   set is the context to use for Emin				      */ +/*   returns 1 if |dn| is finite, non-zero, and <Nmin, 0 otherwise    */ +/* ------------------------------------------------------------------ */ +Int decNumberIsSubnormal(const decNumber *dn, decContext *set) { +  Int ae;				/* adjusted exponent */ +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, dn, set)) return 0; +  #endif + +  if (decNumberIsSpecial(dn)) return 0; /* not finite */ +  if (decNumberIsZero(dn)) return 0;	/* not non-zero */ + +  ae=dn->exponent+dn->digits-1;		/* adjusted exponent */ +  if (ae<set->emin) return 1;		/* is subnormal */ +  return 0; +  } /* decNumberIsSubnormal */ + +/* ------------------------------------------------------------------ */ +/* decNumberTrim -- remove insignificant zeros			      */ +/*								      */ +/*   dn is the number to trim					      */ +/*   returns dn							      */ +/*								      */ +/* All fields are updated as required.	This is a utility operation,  */ +/* so special values are unchanged and no error is possible.	      */ +/* ------------------------------------------------------------------ */ +decNumber * decNumberTrim(decNumber *dn) { +  Int  dropped;			   /* work */ +  decContext set;		   /* .. */ +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, DECUNUSED, dn, DECUNCONT)) return dn; +  #endif +  decContextDefault(&set, DEC_INIT_BASE);    /* clamp=0 */ +  return decTrim(dn, &set, 0, &dropped); +  } /* decNumberTrim */ + +/* ------------------------------------------------------------------ */ +/* decNumberVersion -- return the name and version of this module     */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +const char * decNumberVersion(void) { +  return DECVERSION; +  } /* decNumberVersion */ + +/* ------------------------------------------------------------------ */ +/* decNumberZero -- set a number to 0				      */ +/*								      */ +/*   dn is the number to set, with space for one digit		      */ +/*   returns dn							      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +/* Memset is not used as it is much slower in some environments. */ +decNumber * decNumberZero(decNumber *dn) { + +  #if DECCHECK +  if (decCheckOperands(dn, DECUNUSED, DECUNUSED, DECUNCONT)) return dn; +  #endif + +  dn->bits=0; +  dn->exponent=0; +  dn->digits=1; +  dn->lsu[0]=0; +  return dn; +  } /* decNumberZero */ + +/* ================================================================== */ +/* Local routines						      */ +/* ================================================================== */ + +/* ------------------------------------------------------------------ */ +/* decToString -- lay out a number into a string		      */ +/*								      */ +/*   dn	    is the number to lay out				      */ +/*   string is where to lay out the number			      */ +/*   eng    is 1 if Engineering, 0 if Scientific		      */ +/*								      */ +/* string must be at least dn->digits+14 characters long	      */ +/* No error is possible.					      */ +/*								      */ +/* Note that this routine can generate a -0 or 0.000.  These are      */ +/* never generated in subset to-number or arithmetic, but can occur   */ +/* in non-subset arithmetic (e.g., -1*0 or 1.234-1.234).	      */ +/* ------------------------------------------------------------------ */ +/* If DECCHECK is enabled the string "?" is returned if a number is */ +/* invalid. */ +static void decToString(const decNumber *dn, char *string, Flag eng) { +  Int exp=dn->exponent;	      /* local copy */ +  Int e;		      /* E-part value */ +  Int pre;		      /* digits before the '.' */ +  Int cut;		      /* for counting digits in a Unit */ +  char *c=string;	      /* work [output pointer] */ +  const Unit *up=dn->lsu+D2U(dn->digits)-1; /* -> msu [input pointer] */ +  uInt u, pow;		      /* work */ + +  #if DECCHECK +  if (decCheckOperands(DECUNRESU, dn, DECUNUSED, DECUNCONT)) { +    strcpy(string, "?"); +    return;} +  #endif + +  if (decNumberIsNegative(dn)) {   /* Negatives get a minus */ +    *c='-'; +    c++; +    } +  if (dn->bits&DECSPECIAL) {	   /* Is a special value */ +    if (decNumberIsInfinite(dn)) { +      strcpy(c,	  "Inf"); +      strcpy(c+3, "inity"); +      return;} +    /* a NaN */ +    if (dn->bits&DECSNAN) {	   /* signalling NaN */ +      *c='s'; +      c++; +      } +    strcpy(c, "NaN"); +    c+=3;			   /* step past */ +    /* if not a clean non-zero coefficient, that's all there is in a */ +    /* NaN string */ +    if (exp!=0 || (*dn->lsu==0 && dn->digits==1)) return; +    /* [drop through to add integer] */ +    } + +  /* calculate how many digits in msu, and hence first cut */ +  cut=MSUDIGITS(dn->digits);	   /* [faster than remainder] */ +  cut--;			   /* power of ten for digit */ + +  if (exp==0) {			   /* simple integer [common fastpath] */ +    for (;up>=dn->lsu; up--) {	   /* each Unit from msu */ +      u=*up;			   /* contains DECDPUN digits to lay out */ +      for (; cut>=0; c++, cut--) TODIGIT(u, cut, c, pow); +      cut=DECDPUN-1;		   /* next Unit has all digits */ +      } +    *c='\0';			   /* terminate the string */ +    return;} + +  /* non-0 exponent -- assume plain form */ +  pre=dn->digits+exp;		   /* digits before '.' */ +  e=0;				   /* no E */ +  if ((exp>0) || (pre<-5)) {	   /* need exponential form */ +    e=exp+dn->digits-1;		   /* calculate E value */ +    pre=1;			   /* assume one digit before '.' */ +    if (eng && (e!=0)) {	   /* engineering: may need to adjust */ +      Int adj;			   /* adjustment */ +      /* The C remainder operator is undefined for negative numbers, so */ +      /* a positive remainder calculation must be used here */ +      if (e<0) { +	adj=(-e)%3; +	if (adj!=0) adj=3-adj; +	} +       else { /* e>0 */ +	adj=e%3; +	} +      e=e-adj; +      /* if dealing with zero still produce an exponent which is a */ +      /* multiple of three, as expected, but there will only be the */ +      /* one zero before the E, still.	Otherwise note the padding. */ +      if (!ISZERO(dn)) pre+=adj; +       else {  /* is zero */ +	if (adj!=0) {		   /* 0.00Esnn needed */ +	  e=e+3; +	  pre=-(2-adj); +	  } +	} /* zero */ +      } /* eng */ +    } /* need exponent */ + +  /* lay out the digits of the coefficient, adding 0s and . as needed */ +  u=*up; +  if (pre>0) {			   /* xxx.xxx or xx00 (engineering) form */ +    Int n=pre; +    for (; pre>0; pre--, c++, cut--) { +      if (cut<0) {		   /* need new Unit */ +	if (up==dn->lsu) break;	   /* out of input digits (pre>digits) */ +	up--; +	cut=DECDPUN-1; +	u=*up; +	} +      TODIGIT(u, cut, c, pow); +      } +    if (n<dn->digits) {		   /* more to come, after '.' */ +      *c='.'; c++; +      for (;; c++, cut--) { +	if (cut<0) {		   /* need new Unit */ +	  if (up==dn->lsu) break;  /* out of input digits */ +	  up--; +	  cut=DECDPUN-1; +	  u=*up; +	  } +	TODIGIT(u, cut, c, pow); +	} +      } +     else for (; pre>0; pre--, c++) *c='0'; /* 0 padding (for engineering) needed */ +    } +   else {			   /* 0.xxx or 0.000xxx form */ +    *c='0'; c++; +    *c='.'; c++; +    for (; pre<0; pre++, c++) *c='0';	/* add any 0's after '.' */ +    for (; ; c++, cut--) { +      if (cut<0) {		   /* need new Unit */ +	if (up==dn->lsu) break;	   /* out of input digits */ +	up--; +	cut=DECDPUN-1; +	u=*up; +	} +      TODIGIT(u, cut, c, pow); +      } +    } + +  /* Finally add the E-part, if needed.	 It will never be 0, has a +     base maximum and minimum of +999999999 through -999999999, but +     could range down to -1999999998 for anormal numbers */ +  if (e!=0) { +    Flag had=0;		      /* 1=had non-zero */ +    *c='E'; c++; +    *c='+'; c++;	      /* assume positive */ +    u=e;		      /* .. */ +    if (e<0) { +      *(c-1)='-';	      /* oops, need - */ +      u=-e;		      /* uInt, please */ +      } +    /* lay out the exponent [_itoa or equivalent is not ANSI C] */ +    for (cut=9; cut>=0; cut--) { +      TODIGIT(u, cut, c, pow); +      if (*c=='0' && !had) continue;	/* skip leading zeros */ +      had=1;				/* had non-0 */ +      c++;				/* step for next */ +      } /* cut */ +    } +  *c='\0';	    /* terminate the string (all paths) */ +  return; +  } /* decToString */ + +/* ------------------------------------------------------------------ */ +/* decAddOp -- add/subtract operation				      */ +/*								      */ +/*   This computes C = A + B					      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X+X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*   negate is DECNEG if rhs should be negated, or 0 otherwise	      */ +/*   status accumulates status for the caller			      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/* Inexact in status must be 0 for correct Exact zero sign in result  */ +/* ------------------------------------------------------------------ */ +/* If possible, the coefficient is calculated directly into C.	      */ +/* However, if:							      */ +/*   -- a digits+1 calculation is needed because the numbers are      */ +/*	unaligned and span more than set->digits digits		      */ +/*   -- a carry to digits+1 digits looks possible		      */ +/*   -- C is the same as A or B, and the result would destructively   */ +/*	overlap the A or B coefficient				      */ +/* then the result must be calculated into a temporary buffer.	In    */ +/* this case a local (stack) buffer is used if possible, and only if  */ +/* too long for that does malloc become the final resort.	      */ +/*								      */ +/* Misalignment is handled as follows:				      */ +/*   Apad: (AExp>BExp) Swap operands and proceed as for BExp>AExp.    */ +/*   BPad: Apply the padding by a combination of shifting (whole      */ +/*	   units) and multiplication (part units).		      */ +/*								      */ +/* Addition, especially x=x+1, is speed-critical.		      */ +/* The static buffer is larger than might be expected to allow for    */ +/* calls from higher-level funtions (notable exp).		      */ +/* ------------------------------------------------------------------ */ +static decNumber * decAddOp(decNumber *res, const decNumber *lhs, +			    const decNumber *rhs, decContext *set, +			    uByte negate, uInt *status) { +  #if DECSUBSET +  decNumber *alloclhs=NULL;	   /* non-NULL if rounded lhs allocated */ +  decNumber *allocrhs=NULL;	   /* .., rhs */ +  #endif +  Int	rhsshift;		   /* working shift (in Units) */ +  Int	maxdigits;		   /* longest logical length */ +  Int	mult;			   /* multiplier */ +  Int	residue;		   /* rounding accumulator */ +  uByte bits;			   /* result bits */ +  Flag	diffsign;		   /* non-0 if arguments have different sign */ +  Unit	*acc;			   /* accumulator for result */ +  Unit	accbuff[SD2U(DECBUFFER*2+20)]; /* local buffer [*2+20 reduces many */ +				   /* allocations when called from */ +				   /* other operations, notable exp] */ +  Unit	*allocacc=NULL;		   /* -> allocated acc buffer, iff allocated */ +  Int	reqdigits=set->digits;	   /* local copy; requested DIGITS */ +  Int	padding;		   /* work */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operands and set lostDigits status, as needed */ +      if (lhs->digits>reqdigits) { +	alloclhs=decRoundOperand(lhs, set, status); +	if (alloclhs==NULL) break; +	lhs=alloclhs; +	} +      if (rhs->digits>reqdigits) { +	allocrhs=decRoundOperand(rhs, set, status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* note whether signs differ [used all paths] */ +    diffsign=(Flag)((lhs->bits^rhs->bits^negate)&DECNEG); + +    /* handle infinities and NaNs */ +    if (SPECIALARGS) {			/* a special bit set */ +      if (SPECIALARGS & (DECSNAN | DECNAN))  /* a NaN */ +	decNaNs(res, lhs, rhs, set, status); +       else { /* one or two infinities */ +	if (decNumberIsInfinite(lhs)) { /* LHS is infinity */ +	  /* two infinities with different signs is invalid */ +	  if (decNumberIsInfinite(rhs) && diffsign) { +	    *status|=DEC_Invalid_operation; +	    break; +	    } +	  bits=lhs->bits & DECNEG;	/* get sign from LHS */ +	  } +	 else bits=(rhs->bits^negate) & DECNEG;/* RHS must be Infinity */ +	bits|=DECINF; +	decNumberZero(res); +	res->bits=bits;			/* set +/- infinity */ +	} /* an infinity */ +      break; +      } + +    /* Quick exit for add 0s; return the non-0, modified as need be */ +    if (ISZERO(lhs)) { +      Int adjust;			/* work */ +      Int lexp=lhs->exponent;		/* save in case LHS==RES */ +      bits=lhs->bits;			/* .. */ +      residue=0;			/* clear accumulator */ +      decCopyFit(res, rhs, set, &residue, status); /* copy (as needed) */ +      res->bits^=negate;		/* flip if rhs was negated */ +      #if DECSUBSET +      if (set->extended) {		/* exponents on zeros count */ +      #endif +	/* exponent will be the lower of the two */ +	adjust=lexp-res->exponent;	/* adjustment needed [if -ve] */ +	if (ISZERO(res)) {		/* both 0: special IEEE 854 rules */ +	  if (adjust<0) res->exponent=lexp;  /* set exponent */ +	  /* 0-0 gives +0 unless rounding to -infinity, and -0-0 gives -0 */ +	  if (diffsign) { +	    if (set->round!=DEC_ROUND_FLOOR) res->bits=0; +	     else res->bits=DECNEG;	/* preserve 0 sign */ +	    } +	  } +	 else { /* non-0 res */ +	  if (adjust<0) {     /* 0-padding needed */ +	    if ((res->digits-adjust)>set->digits) { +	      adjust=res->digits-set->digits;	  /* to fit exactly */ +	      *status|=DEC_Rounded;		  /* [but exact] */ +	      } +	    res->digits=decShiftToMost(res->lsu, res->digits, -adjust); +	    res->exponent+=adjust;		  /* set the exponent. */ +	    } +	  } /* non-0 res */ +      #if DECSUBSET +	} /* extended */ +      #endif +      decFinish(res, set, &residue, status);	  /* clean and finalize */ +      break;} + +    if (ISZERO(rhs)) {			/* [lhs is non-zero] */ +      Int adjust;			/* work */ +      Int rexp=rhs->exponent;		/* save in case RHS==RES */ +      bits=rhs->bits;			/* be clean */ +      residue=0;			/* clear accumulator */ +      decCopyFit(res, lhs, set, &residue, status); /* copy (as needed) */ +      #if DECSUBSET +      if (set->extended) {		/* exponents on zeros count */ +      #endif +	/* exponent will be the lower of the two */ +	/* [0-0 case handled above] */ +	adjust=rexp-res->exponent;	/* adjustment needed [if -ve] */ +	if (adjust<0) {	    /* 0-padding needed */ +	  if ((res->digits-adjust)>set->digits) { +	    adjust=res->digits-set->digits;	/* to fit exactly */ +	    *status|=DEC_Rounded;		/* [but exact] */ +	    } +	  res->digits=decShiftToMost(res->lsu, res->digits, -adjust); +	  res->exponent+=adjust;		/* set the exponent. */ +	  } +      #if DECSUBSET +	} /* extended */ +      #endif +      decFinish(res, set, &residue, status);	  /* clean and finalize */ +      break;} + +    /* [NB: both fastpath and mainpath code below assume these cases */ +    /* (notably 0-0) have already been handled] */ + +    /* calculate the padding needed to align the operands */ +    padding=rhs->exponent-lhs->exponent; + +    /* Fastpath cases where the numbers are aligned and normal, the RHS */ +    /* is all in one unit, no operand rounding is needed, and no carry, */ +    /* lengthening, or borrow is needed */ +    if (padding==0 +	&& rhs->digits<=DECDPUN +	&& rhs->exponent>=set->emin	/* [some normals drop through] */ +	&& rhs->exponent<=set->emax-set->digits+1 /* [could clamp] */ +	&& rhs->digits<=reqdigits +	&& lhs->digits<=reqdigits) { +      Int partial=*lhs->lsu; +      if (!diffsign) {			/* adding */ +	partial+=*rhs->lsu; +	if ((partial<=DECDPUNMAX)	/* result fits in unit */ +	 && (lhs->digits>=DECDPUN ||	/* .. and no digits-count change */ +	     partial<(Int)powers[lhs->digits])) { /* .. */ +	  if (res!=lhs) decNumberCopy(res, lhs);  /* not in place */ +	  *res->lsu=(Unit)partial;	/* [copy could have overwritten RHS] */ +	  break; +	  } +	/* else drop out for careful add */ +	} +       else {				/* signs differ */ +	partial-=*rhs->lsu; +	if (partial>0) { /* no borrow needed, and non-0 result */ +	  if (res!=lhs) decNumberCopy(res, lhs);  /* not in place */ +	  *res->lsu=(Unit)partial; +	  /* this could have reduced digits [but result>0] */ +	  res->digits=decGetDigits(res->lsu, D2U(res->digits)); +	  break; +	  } +	/* else drop out for careful subtract */ +	} +      } + +    /* Now align (pad) the lhs or rhs so they can be added or */ +    /* subtracted, as necessary.  If one number is much larger than */ +    /* the other (that is, if in plain form there is a least one */ +    /* digit between the lowest digit of one and the highest of the */ +    /* other) padding with up to DIGITS-1 trailing zeros may be */ +    /* needed; then apply rounding (as exotic rounding modes may be */ +    /* affected by the residue). */ +    rhsshift=0;		      /* rhs shift to left (padding) in Units */ +    bits=lhs->bits;	      /* assume sign is that of LHS */ +    mult=1;		      /* likely multiplier */ + +    /* [if padding==0 the operands are aligned; no padding is needed] */ +    if (padding!=0) { +      /* some padding needed; always pad the RHS, as any required */ +      /* padding can then be effected by a simple combination of */ +      /* shifts and a multiply */ +      Flag swapped=0; +      if (padding<0) {			/* LHS needs the padding */ +	const decNumber *t; +	padding=-padding;		/* will be +ve */ +	bits=(uByte)(rhs->bits^negate); /* assumed sign is now that of RHS */ +	t=lhs; lhs=rhs; rhs=t; +	swapped=1; +	} + +      /* If, after pad, rhs would be longer than lhs by digits+1 or */ +      /* more then lhs cannot affect the answer, except as a residue, */ +      /* so only need to pad up to a length of DIGITS+1. */ +      if (rhs->digits+padding > lhs->digits+reqdigits+1) { +	/* The RHS is sufficient */ +	/* for residue use the relative sign indication... */ +	Int shift=reqdigits-rhs->digits;     /* left shift needed */ +	residue=1;			     /* residue for rounding */ +	if (diffsign) residue=-residue;	     /* signs differ */ +	/* copy, shortening if necessary */ +	decCopyFit(res, rhs, set, &residue, status); +	/* if it was already shorter, then need to pad with zeros */ +	if (shift>0) { +	  res->digits=decShiftToMost(res->lsu, res->digits, shift); +	  res->exponent-=shift;		     /* adjust the exponent. */ +	  } +	/* flip the result sign if unswapped and rhs was negated */ +	if (!swapped) res->bits^=negate; +	decFinish(res, set, &residue, status);	  /* done */ +	break;} + +      /* LHS digits may affect result */ +      rhsshift=D2U(padding+1)-1;	/* this much by Unit shift .. */ +      mult=powers[padding-(rhsshift*DECDPUN)]; /* .. this by multiplication */ +      } /* padding needed */ + +    if (diffsign) mult=-mult;		/* signs differ */ + +    /* determine the longer operand */ +    maxdigits=rhs->digits+padding;	/* virtual length of RHS */ +    if (lhs->digits>maxdigits) maxdigits=lhs->digits; + +    /* Decide on the result buffer to use; if possible place directly */ +    /* into result. */ +    acc=res->lsu;			/* assume add direct to result */ +    /* If destructive overlap, or the number is too long, or a carry or */ +    /* borrow to DIGITS+1 might be possible, a buffer must be used. */ +    /* [Might be worth more sophisticated tests when maxdigits==reqdigits] */ +    if ((maxdigits>=reqdigits)		/* is, or could be, too large */ +     || (res==rhs && rhsshift>0)) {	/* destructive overlap */ +      /* buffer needed, choose it; units for maxdigits digits will be */ +      /* needed, +1 Unit for carry or borrow */ +      Int need=D2U(maxdigits)+1; +      acc=accbuff;			/* assume use local buffer */ +      if (need*sizeof(Unit)>sizeof(accbuff)) { +	/* printf("malloc add %ld %ld\n", need, sizeof(accbuff)); */ +	allocacc=(Unit *)malloc(need*sizeof(Unit)); +	if (allocacc==NULL) {		/* hopeless -- abandon */ +	  *status|=DEC_Insufficient_storage; +	  break;} +	acc=allocacc; +	} +      } + +    res->bits=(uByte)(bits&DECNEG);	/* it's now safe to overwrite.. */ +    res->exponent=lhs->exponent;	/* .. operands (even if aliased) */ + +    #if DECTRACE +      decDumpAr('A', lhs->lsu, D2U(lhs->digits)); +      decDumpAr('B', rhs->lsu, D2U(rhs->digits)); +      printf("	:h: %ld %ld\n", rhsshift, mult); +    #endif + +    /* add [A+B*m] or subtract [A+B*(-m)] */ +    res->digits=decUnitAddSub(lhs->lsu, D2U(lhs->digits), +			      rhs->lsu, D2U(rhs->digits), +			      rhsshift, acc, mult) +	       *DECDPUN;	   /* [units -> digits] */ +    if (res->digits<0) {	   /* borrowed... */ +      res->digits=-res->digits; +      res->bits^=DECNEG;	   /* flip the sign */ +      } +    #if DECTRACE +      decDumpAr('+', acc, D2U(res->digits)); +    #endif + +    /* If a buffer was used the result must be copied back, possibly */ +    /* shortening.  (If no buffer was used then the result must have */ +    /* fit, so can't need rounding and residue must be 0.) */ +    residue=0;			   /* clear accumulator */ +    if (acc!=res->lsu) { +      #if DECSUBSET +      if (set->extended) {	   /* round from first significant digit */ +      #endif +	/* remove leading zeros that were added due to rounding up to */ +	/* integral Units -- before the test for rounding. */ +	if (res->digits>reqdigits) +	  res->digits=decGetDigits(acc, D2U(res->digits)); +	decSetCoeff(res, set, acc, res->digits, &residue, status); +      #if DECSUBSET +	} +       else { /* subset arithmetic rounds from original significant digit */ +	/* May have an underestimate.  This only occurs when both */ +	/* numbers fit in DECDPUN digits and are padding with a */ +	/* negative multiple (-10, -100...) and the top digit(s) become */ +	/* 0.  (This only matters when using X3.274 rules where the */ +	/* leading zero could be included in the rounding.) */ +	if (res->digits<maxdigits) { +	  *(acc+D2U(res->digits))=0; /* ensure leading 0 is there */ +	  res->digits=maxdigits; +	  } +	 else { +	  /* remove leading zeros that added due to rounding up to */ +	  /* integral Units (but only those in excess of the original */ +	  /* maxdigits length, unless extended) before test for rounding. */ +	  if (res->digits>reqdigits) { +	    res->digits=decGetDigits(acc, D2U(res->digits)); +	    if (res->digits<maxdigits) res->digits=maxdigits; +	    } +	  } +	decSetCoeff(res, set, acc, res->digits, &residue, status); +	/* Now apply rounding if needed before removing leading zeros. */ +	/* This is safe because subnormals are not a possibility */ +	if (residue!=0) { +	  decApplyRound(res, set, residue, status); +	  residue=0;		     /* did what needed to be done */ +	  } +	} /* subset */ +      #endif +      } /* used buffer */ + +    /* strip leading zeros [these were left on in case of subset subtract] */ +    res->digits=decGetDigits(res->lsu, D2U(res->digits)); + +    /* apply checks and rounding */ +    decFinish(res, set, &residue, status); + +    /* "When the sum of two operands with opposite signs is exactly */ +    /* zero, the sign of that sum shall be '+' in all rounding modes */ +    /* except round toward -Infinity, in which mode that sign shall be */ +    /* '-'."  [Subset zeros also never have '-', set by decFinish.] */ +    if (ISZERO(res) && diffsign +     #if DECSUBSET +     && set->extended +     #endif +     && (*status&DEC_Inexact)==0) { +      if (set->round==DEC_ROUND_FLOOR) res->bits|=DECNEG;   /* sign - */ +				  else res->bits&=~DECNEG;  /* sign + */ +      } +    } while(0);				     /* end protected */ + +  if (allocacc!=NULL) free(allocacc);	     /* drop any storage used */ +  #if DECSUBSET +  if (allocrhs!=NULL) free(allocrhs);	     /* .. */ +  if (alloclhs!=NULL) free(alloclhs);	     /* .. */ +  #endif +  return res; +  } /* decAddOp */ + +/* ------------------------------------------------------------------ */ +/* decDivideOp -- division operation				      */ +/*								      */ +/*  This routine performs the calculations for all four division      */ +/*  operators (divide, divideInteger, remainder, remainderNear).      */ +/*								      */ +/*  C=A op B							      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X/X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*   op	 is DIVIDE, DIVIDEINT, REMAINDER, or REMNEAR respectively.    */ +/*   status is the usual accumulator				      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* ------------------------------------------------------------------ */ +/*   The underlying algorithm of this routine is the same as in the   */ +/*   1981 S/370 implementation, that is, non-restoring long division  */ +/*   with bi-unit (rather than bi-digit) estimation for each unit     */ +/*   multiplier.  In this pseudocode overview, complications for the  */ +/*   Remainder operators and division residues for exact rounding are */ +/*   omitted for clarity.					      */ +/*								      */ +/*     Prepare operands and handle special values		      */ +/*     Test for x/0 and then 0/x				      */ +/*     Exp =Exp1 - Exp2						      */ +/*     Exp =Exp +len(var1) -len(var2)				      */ +/*     Sign=Sign1 * Sign2					      */ +/*     Pad accumulator (Var1) to double-length with 0's (pad1)	      */ +/*     Pad Var2 to same length as Var1				      */ +/*     msu2pair/plus=1st 2 or 1 units of var2, +1 to allow for round  */ +/*     have=0							      */ +/*     Do until (have=digits+1 OR residue=0)			      */ +/*	 if exp<0 then if integer divide/residue then leave	      */ +/*	 this_unit=0						      */ +/*	 Do forever						      */ +/*	    compare numbers					      */ +/*	    if <0 then leave inner_loop				      */ +/*	    if =0 then (* quick exit without subtract *) do	      */ +/*	       this_unit=this_unit+1; output this_unit		      */ +/*	       leave outer_loop; end				      */ +/*	    Compare lengths of numbers (mantissae):		      */ +/*	    If same then tops2=msu2pair -- {units 1&2 of var2}	      */ +/*		    else tops2=msu2plus -- {0, unit 1 of var2}	      */ +/*	    tops1=first_unit_of_Var1*10**DECDPUN +second_unit_of_var1 */ +/*	    mult=tops1/tops2  -- Good and safe guess at divisor	      */ +/*	    if mult=0 then mult=1				      */ +/*	    this_unit=this_unit+mult				      */ +/*	    subtract						      */ +/*	    end inner_loop					      */ +/*	  if have\=0 | this_unit\=0 then do			      */ +/*	    output this_unit					      */ +/*	    have=have+1; end					      */ +/*	  var2=var2/10						      */ +/*	  exp=exp-1						      */ +/*	  end outer_loop					      */ +/*     exp=exp+1   -- set the proper exponent			      */ +/*     if have=0 then generate answer=0				      */ +/*     Return (Result is defined by Var1)			      */ +/*								      */ +/* ------------------------------------------------------------------ */ +/* Two working buffers are needed during the division; one (digits+   */ +/* 1) to accumulate the result, and the other (up to 2*digits+1) for  */ +/* long subtractions.  These are acc and var1 respectively.	      */ +/* var1 is a copy of the lhs coefficient, var2 is the rhs coefficient.*/ +/* The static buffers may be larger than might be expected to allow   */ +/* for calls from higher-level funtions (notable exp).		      */ +/* ------------------------------------------------------------------ */ +static decNumber * decDivideOp(decNumber *res, +			       const decNumber *lhs, const decNumber *rhs, +			       decContext *set, Flag op, uInt *status) { +  #if DECSUBSET +  decNumber *alloclhs=NULL;	   /* non-NULL if rounded lhs allocated */ +  decNumber *allocrhs=NULL;	   /* .., rhs */ +  #endif +  Unit	accbuff[SD2U(DECBUFFER+DECDPUN+10)]; /* local buffer */ +  Unit	*acc=accbuff;		   /* -> accumulator array for result */ +  Unit	*allocacc=NULL;		   /* -> allocated buffer, iff allocated */ +  Unit	*accnext;		   /* -> where next digit will go */ +  Int	acclength;		   /* length of acc needed [Units] */ +  Int	accunits;		   /* count of units accumulated */ +  Int	accdigits;		   /* count of digits accumulated */ + +  Unit	varbuff[SD2U(DECBUFFER*2+DECDPUN)*sizeof(Unit)]; /* buffer for var1 */ +  Unit	*var1=varbuff;		   /* -> var1 array for long subtraction */ +  Unit	*varalloc=NULL;		   /* -> allocated buffer, iff used */ +  Unit	*msu1;			   /* -> msu of var1 */ + +  const Unit *var2;		   /* -> var2 array */ +  const Unit *msu2;		   /* -> msu of var2 */ +  Int	msu2plus;		   /* msu2 plus one [does not vary] */ +  eInt	msu2pair;		   /* msu2 pair plus one [does not vary] */ + +  Int	var1units, var2units;	   /* actual lengths */ +  Int	var2ulen;		   /* logical length (units) */ +  Int	var1initpad=0;		   /* var1 initial padding (digits) */ +  Int	maxdigits;		   /* longest LHS or required acc length */ +  Int	mult;			   /* multiplier for subtraction */ +  Unit	thisunit;		   /* current unit being accumulated */ +  Int	residue;		   /* for rounding */ +  Int	reqdigits=set->digits;	   /* requested DIGITS */ +  Int	exponent;		   /* working exponent */ +  Int	maxexponent=0;		   /* DIVIDE maximum exponent if unrounded */ +  uByte bits;			   /* working sign */ +  Unit	*target;		   /* work */ +  const Unit *source;		   /* .. */ +  uLong const *pow;                /* .. */ +  Int	shift, cut;		   /* .. */ +  #if DECSUBSET +  Int	dropped;		   /* work */ +  #endif + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operands and set lostDigits status, as needed */ +      if (lhs->digits>reqdigits) { +	alloclhs=decRoundOperand(lhs, set, status); +	if (alloclhs==NULL) break; +	lhs=alloclhs; +	} +      if (rhs->digits>reqdigits) { +	allocrhs=decRoundOperand(rhs, set, status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    bits=(lhs->bits^rhs->bits)&DECNEG;	/* assumed sign for divisions */ + +    /* handle infinities and NaNs */ +    if (SPECIALARGS) {			/* a special bit set */ +      if (SPECIALARGS & (DECSNAN | DECNAN)) { /* one or two NaNs */ +	decNaNs(res, lhs, rhs, set, status); +	break; +	} +      /* one or two infinities */ +      if (decNumberIsInfinite(lhs)) {	/* LHS (dividend) is infinite */ +	if (decNumberIsInfinite(rhs) || /* two infinities are invalid .. */ +	    op & (REMAINDER | REMNEAR)) { /* as is remainder of infinity */ +	  *status|=DEC_Invalid_operation; +	  break; +	  } +	/* [Note that infinity/0 raises no exceptions] */ +	decNumberZero(res); +	res->bits=bits|DECINF;		/* set +/- infinity */ +	break; +	} +       else {				/* RHS (divisor) is infinite */ +	residue=0; +	if (op&(REMAINDER|REMNEAR)) { +	  /* result is [finished clone of] lhs */ +	  decCopyFit(res, lhs, set, &residue, status); +	  } +	 else {	 /* a division */ +	  decNumberZero(res); +	  res->bits=bits;		/* set +/- zero */ +	  /* for DIVIDEINT the exponent is always 0.  For DIVIDE, result */ +	  /* is a 0 with infinitely negative exponent, clamped to minimum */ +	  if (op&DIVIDE) { +	    res->exponent=set->emin-set->digits+1; +	    *status|=DEC_Clamped; +	    } +	  } +	decFinish(res, set, &residue, status); +	break; +	} +      } + +    /* handle 0 rhs (x/0) */ +    if (ISZERO(rhs)) {			/* x/0 is always exceptional */ +      if (ISZERO(lhs)) { +	decNumberZero(res);		/* [after lhs test] */ +	*status|=DEC_Division_undefined;/* 0/0 will become NaN */ +	} +       else { +	decNumberZero(res); +	if (op&(REMAINDER|REMNEAR)) *status|=DEC_Invalid_operation; +	 else { +	  *status|=DEC_Division_by_zero; /* x/0 */ +	  res->bits=bits|DECINF;	 /* .. is +/- Infinity */ +	  } +	} +      break;} + +    /* handle 0 lhs (0/x) */ +    if (ISZERO(lhs)) {			/* 0/x [x!=0] */ +      #if DECSUBSET +      if (!set->extended) decNumberZero(res); +       else { +      #endif +	if (op&DIVIDE) { +	  residue=0; +	  exponent=lhs->exponent-rhs->exponent; /* ideal exponent */ +	  decNumberCopy(res, lhs);	/* [zeros always fit] */ +	  res->bits=bits;		/* sign as computed */ +	  res->exponent=exponent;	/* exponent, too */ +	  decFinalize(res, set, &residue, status);   /* check exponent */ +	  } +	 else if (op&DIVIDEINT) { +	  decNumberZero(res);		/* integer 0 */ +	  res->bits=bits;		/* sign as computed */ +	  } +	 else {				/* a remainder */ +	  exponent=rhs->exponent;	/* [save in case overwrite] */ +	  decNumberCopy(res, lhs);	/* [zeros always fit] */ +	  if (exponent<res->exponent) res->exponent=exponent; /* use lower */ +	  } +      #if DECSUBSET +	} +      #endif +      break;} + +    /* Precalculate exponent.  This starts off adjusted (and hence fits */ +    /* in 31 bits) and becomes the usual unadjusted exponent as the */ +    /* division proceeds.  The order of evaluation is important, here, */ +    /* to avoid wrap. */ +    exponent=(lhs->exponent+lhs->digits)-(rhs->exponent+rhs->digits); + +    /* If the working exponent is -ve, then some quick exits are */ +    /* possible because the quotient is known to be <1 */ +    /* [for REMNEAR, it needs to be < -1, as -0.5 could need work] */ +    if (exponent<0 && !(op==DIVIDE)) { +      if (op&DIVIDEINT) { +	decNumberZero(res);		     /* integer part is 0 */ +	#if DECSUBSET +	if (set->extended) +	#endif +	  res->bits=bits;		     /* set +/- zero */ +	break;} +      /* fastpath remainders so long as the lhs has the smaller */ +      /* (or equal) exponent */ +      if (lhs->exponent<=rhs->exponent) { +	if (op&REMAINDER || exponent<-1) { +	  /* It is REMAINDER or safe REMNEAR; result is [finished */ +	  /* clone of] lhs  (r = x - 0*y) */ +	  residue=0; +	  decCopyFit(res, lhs, set, &residue, status); +	  decFinish(res, set, &residue, status); +	  break; +	  } +	/* [unsafe REMNEAR drops through] */ +	} +      } /* fastpaths */ + +    /* Long (slow) division is needed; roll up the sleeves... */ + +    /* The accumulator will hold the quotient of the division. */ +    /* If it needs to be too long for stack storage, then allocate. */ +    acclength=D2U(reqdigits+DECDPUN);	/* in Units */ +    if (acclength*sizeof(Unit)>sizeof(accbuff)) { +      /* printf("malloc dvacc %ld units\n", acclength); */ +      allocacc=(Unit *)malloc(acclength*sizeof(Unit)); +      if (allocacc==NULL) {		/* hopeless -- abandon */ +	*status|=DEC_Insufficient_storage; +	break;} +      acc=allocacc;			/* use the allocated space */ +      } + +    /* var1 is the padded LHS ready for subtractions. */ +    /* If it needs to be too long for stack storage, then allocate. */ +    /* The maximum units needed for var1 (long subtraction) is: */ +    /* Enough for */ +    /*	   (rhs->digits+reqdigits-1) -- to allow full slide to right */ +    /* or  (lhs->digits)	     -- to allow for long lhs */ +    /* whichever is larger */ +    /*	 +1		   -- for rounding of slide to right */ +    /*	 +1		   -- for leading 0s */ +    /*	 +1		   -- for pre-adjust if a remainder or DIVIDEINT */ +    /* [Note: unused units do not participate in decUnitAddSub data] */ +    maxdigits=rhs->digits+reqdigits-1; +    if (lhs->digits>maxdigits) maxdigits=lhs->digits; +    var1units=D2U(maxdigits)+2; +    /* allocate a guard unit above msu1 for REMAINDERNEAR */ +    if (!(op&DIVIDE)) var1units++; +    if ((var1units+1)*sizeof(Unit)>sizeof(varbuff)) { +      /* printf("malloc dvvar %ld units\n", var1units+1); */ +      varalloc=(Unit *)malloc((var1units+1)*sizeof(Unit)); +      if (varalloc==NULL) {		/* hopeless -- abandon */ +	*status|=DEC_Insufficient_storage; +	break;} +      var1=varalloc;			/* use the allocated space */ +      } + +    /* Extend the lhs and rhs to full long subtraction length.	The lhs */ +    /* is truly extended into the var1 buffer, with 0 padding, so a */ +    /* subtract in place is always possible.  The rhs (var2) has */ +    /* virtual padding (implemented by decUnitAddSub). */ +    /* One guard unit was allocated above msu1 for rem=rem+rem in */ +    /* REMAINDERNEAR. */ +    msu1=var1+var1units-1;		/* msu of var1 */ +    source=lhs->lsu+D2U(lhs->digits)-1; /* msu of input array */ +    for (target=msu1; source>=lhs->lsu; source--, target--) *target=*source; +    for (; target>=var1; target--) *target=0; + +    /* rhs (var2) is left-aligned with var1 at the start */ +    var2ulen=var1units;			/* rhs logical length (units) */ +    var2units=D2U(rhs->digits);		/* rhs actual length (units) */ +    var2=rhs->lsu;			/* -> rhs array */ +    msu2=var2+var2units-1;		/* -> msu of var2 [never changes] */ +    /* now set up the variables which will be used for estimating the */ +    /* multiplication factor.  If these variables are not exact, add */ +    /* 1 to make sure that the multiplier is never overestimated. */ +    msu2plus=*msu2;			/* it's value .. */ +    if (var2units>1) msu2plus++;	/* .. +1 if any more */ +    msu2pair=(eInt)*msu2*(DECDPUNMAX+1);/* top two pair .. */ +    if (var2units>1) {			/* .. [else treat 2nd as 0] */ +      msu2pair+=*(msu2-1);		/* .. */ +      if (var2units>2) msu2pair++;	/* .. +1 if any more */ +      } + +    /* The calculation is working in units, which may have leading zeros, */ +    /* but the exponent was calculated on the assumption that they are */ +    /* both left-aligned.  Adjust the exponent to compensate: add the */ +    /* number of leading zeros in var1 msu and subtract those in var2 msu. */ +    /* [This is actually done by counting the digits and negating, as */ +    /* lead1=DECDPUN-digits1, and similarly for lead2.] */ +    for (pow=&powers[1]; *msu1>=*pow; pow++) exponent--; +    for (pow=&powers[1]; *msu2>=*pow; pow++) exponent++; + +    /* Now, if doing an integer divide or remainder, ensure that */ +    /* the result will be Unit-aligned.	 To do this, shift the var1 */ +    /* accumulator towards least if need be.  (It's much easier to */ +    /* do this now than to reassemble the residue afterwards, if */ +    /* doing a remainder.)  Also ensure the exponent is not negative. */ +    if (!(op&DIVIDE)) { +      Unit *u;				/* work */ +      /* save the initial 'false' padding of var1, in digits */ +      var1initpad=(var1units-D2U(lhs->digits))*DECDPUN; +      /* Determine the shift to do. */ +      if (exponent<0) cut=-exponent; +       else cut=DECDPUN-exponent%DECDPUN; +      decShiftToLeast(var1, var1units, cut); +      exponent+=cut;			/* maintain numerical value */ +      var1initpad-=cut;			/* .. and reduce padding */ +      /* clean any most-significant units which were just emptied */ +      for (u=msu1; cut>=DECDPUN; cut-=DECDPUN, u--) *u=0; +      } /* align */ +     else { /* is DIVIDE */ +      maxexponent=lhs->exponent-rhs->exponent;	  /* save */ +      /* optimization: if the first iteration will just produce 0, */ +      /* preadjust to skip it [valid for DIVIDE only] */ +      if (*msu1<*msu2) { +	var2ulen--;			/* shift down */ +	exponent-=DECDPUN;		/* update the exponent */ +	} +      } + +    /* ---- start the long-division loops ------------------------------ */ +    accunits=0;				/* no units accumulated yet */ +    accdigits=0;			/* .. or digits */ +    accnext=acc+acclength-1;		/* -> msu of acc [NB: allows digits+1] */ +    for (;;) {				/* outer forever loop */ +      thisunit=0;			/* current unit assumed 0 */ +      /* find the next unit */ +      for (;;) {			/* inner forever loop */ +	/* strip leading zero units [from either pre-adjust or from */ +	/* subtract last time around].	Leave at least one unit. */ +	for (; *msu1==0 && msu1>var1; msu1--) var1units--; + +	if (var1units<var2ulen) break;	     /* var1 too low for subtract */ +	if (var1units==var2ulen) {	     /* unit-by-unit compare needed */ +	  /* compare the two numbers, from msu */ +	  const Unit *pv1, *pv2; +	  Unit v2;			     /* units to compare */ +	  pv2=msu2;			     /* -> msu */ +	  for (pv1=msu1; ; pv1--, pv2--) { +	    /* v1=*pv1 -- always OK */ +	    v2=0;			     /* assume in padding */ +	    if (pv2>=var2) v2=*pv2;	     /* in range */ +	    if (*pv1!=v2) break;	     /* no longer the same */ +	    if (pv1==var1) break;	     /* done; leave pv1 as is */ +	    } +	  /* here when all inspected or a difference seen */ +	  if (*pv1<v2) break;		     /* var1 too low to subtract */ +	  if (*pv1==v2) {		     /* var1 == var2 */ +	    /* reach here if var1 and var2 are identical; subtraction */ +	    /* would increase digit by one, and the residue will be 0 so */ +	    /* the calculation is done; leave the loop with residue=0. */ +	    thisunit++;			     /* as though subtracted */ +	    *var1=0;			     /* set var1 to 0 */ +	    var1units=1;		     /* .. */ +	    break;  /* from inner */ +	    } /* var1 == var2 */ +	  /* *pv1>v2.  Prepare for real subtraction; the lengths are equal */ +	  /* Estimate the multiplier (there's always a msu1-1)... */ +	  /* Bring in two units of var2 to provide a good estimate. */ +	  mult=(Int)(((eInt)*msu1*(DECDPUNMAX+1)+*(msu1-1))/msu2pair); +	  } /* lengths the same */ +	 else { /* var1units > var2ulen, so subtraction is safe */ +	  /* The var2 msu is one unit towards the lsu of the var1 msu, */ +	  /* so only one unit for var2 can be used. */ +	  mult=(Int)(((eInt)*msu1*(DECDPUNMAX+1)+*(msu1-1))/msu2plus); +	  } +	if (mult==0) mult=1;		     /* must always be at least 1 */ +	/* subtraction needed; var1 is > var2 */ +	thisunit=(Unit)(thisunit+mult);	     /* accumulate */ +	/* subtract var1-var2, into var1; only the overlap needs */ +	/* processing, as this is an in-place calculation */ +	shift=var2ulen-var2units; +	#if DECTRACE +	  decDumpAr('1', &var1[shift], var1units-shift); +	  decDumpAr('2', var2, var2units); +	  printf("m=%ld\n", -mult); +	#endif +	decUnitAddSub(&var1[shift], var1units-shift, +		      var2, var2units, 0, +		      &var1[shift], -mult); +	#if DECTRACE +	  decDumpAr('#', &var1[shift], var1units-shift); +	#endif +	/* var1 now probably has leading zeros; these are removed at the */ +	/* top of the inner loop. */ +	} /* inner loop */ + +      /* The next unit has been calculated in full; unless it's a */ +      /* leading zero, add to acc */ +      if (accunits!=0 || thisunit!=0) {	     /* is first or non-zero */ +	*accnext=thisunit;		     /* store in accumulator */ +	/* account exactly for the new digits */ +	if (accunits==0) { +	  accdigits++;			     /* at least one */ +	  for (pow=&powers[1]; thisunit>=*pow; pow++) accdigits++; +	  } +	 else accdigits+=DECDPUN; +	accunits++;			     /* update count */ +	accnext--;			     /* ready for next */ +	if (accdigits>reqdigits) break;	     /* have enough digits */ +	} + +      /* if the residue is zero, the operation is done (unless divide */ +      /* or divideInteger and still not enough digits yet) */ +      if (*var1==0 && var1units==1) {	     /* residue is 0 */ +	if (op&(REMAINDER|REMNEAR)) break; +	if ((op&DIVIDE) && (exponent<=maxexponent)) break; +	/* [drop through if divideInteger] */ +	} +      /* also done enough if calculating remainder or integer */ +      /* divide and just did the last ('units') unit */ +      if (exponent==0 && !(op&DIVIDE)) break; + +      /* to get here, var1 is less than var2, so divide var2 by the per- */ +      /* Unit power of ten and go for the next digit */ +      var2ulen--;			     /* shift down */ +      exponent-=DECDPUN;		     /* update the exponent */ +      } /* outer loop */ + +    /* ---- division is complete --------------------------------------- */ +    /* here: acc      has at least reqdigits+1 of good results (or fewer */ +    /*		      if early stop), starting at accnext+1 (its lsu) */ +    /*	     var1     has any residue at the stopping point */ +    /*	     accunits is the number of digits collected in acc */ +    if (accunits==0) {		   /* acc is 0 */ +      accunits=1;		   /* show have a unit .. */ +      accdigits=1;		   /* .. */ +      *accnext=0;		   /* .. whose value is 0 */ +      } +     else accnext++;		   /* back to last placed */ +    /* accnext now -> lowest unit of result */ + +    residue=0;			   /* assume no residue */ +    if (op&DIVIDE) { +      /* record the presence of any residue, for rounding */ +      if (*var1!=0 || var1units>1) residue=1; +       else { /* no residue */ +	/* Had an exact division; clean up spurious trailing 0s. */ +	/* There will be at most DECDPUN-1, from the final multiply, */ +	/* and then only if the result is non-0 (and even) and the */ +	/* exponent is 'loose'. */ +	#if DECDPUN>1 +	Unit lsu=*accnext; +	if (!(lsu&0x01) && (lsu!=0)) { +	  /* count the trailing zeros */ +	  Int drop=0; +	  for (;; drop++) {    /* [will terminate because lsu!=0] */ +	    if (exponent>=maxexponent) break;	  /* don't chop real 0s */ +	    #if DECDPUN<=4 +	      if ((lsu-QUOT10(lsu, drop+1) +		  *powers[drop+1])!=0) break;	  /* found non-0 digit */ +	    #else +	      if (lsu%powers[drop+1]!=0) break;	  /* found non-0 digit */ +	    #endif +	    exponent++; +	    } +	  if (drop>0) { +	    accunits=decShiftToLeast(accnext, accunits, drop); +	    accdigits=decGetDigits(accnext, accunits); +	    accunits=D2U(accdigits); +	    /* [exponent was adjusted in the loop] */ +	    } +	  } /* neither odd nor 0 */ +	#endif +	} /* exact divide */ +      } /* divide */ +     else /* op!=DIVIDE */ { +      /* check for coefficient overflow */ +      if (accdigits+exponent>reqdigits) { +	*status|=DEC_Division_impossible; +	break; +	} +      if (op & (REMAINDER|REMNEAR)) { +	/* [Here, the exponent will be 0, because var1 was adjusted */ +	/* appropriately.] */ +	Int postshift;			     /* work */ +	Flag wasodd=0;			     /* integer was odd */ +	Unit *quotlsu;			     /* for save */ +	Int  quotdigits;		     /* .. */ + +	bits=lhs->bits;			     /* remainder sign is always as lhs */ + +	/* Fastpath when residue is truly 0 is worthwhile [and */ +	/* simplifies the code below] */ +	if (*var1==0 && var1units==1) {	     /* residue is 0 */ +	  Int exp=lhs->exponent;	     /* save min(exponents) */ +	  if (rhs->exponent<exp) exp=rhs->exponent; +	  decNumberZero(res);		     /* 0 coefficient */ +	  #if DECSUBSET +	  if (set->extended) +	  #endif +	  res->exponent=exp;		     /* .. with proper exponent */ +	  res->bits=(uByte)(bits&DECNEG);	   /* [cleaned] */ +	  decFinish(res, set, &residue, status);   /* might clamp */ +	  break; +	  } +	/* note if the quotient was odd */ +	if (*accnext & 0x01) wasodd=1;	     /* acc is odd */ +	quotlsu=accnext;		     /* save in case need to reinspect */ +	quotdigits=accdigits;		     /* .. */ + +	/* treat the residue, in var1, as the value to return, via acc */ +	/* calculate the unused zero digits.  This is the smaller of: */ +	/*   var1 initial padding (saved above) */ +	/*   var2 residual padding, which happens to be given by: */ +	postshift=var1initpad+exponent-lhs->exponent+rhs->exponent; +	/* [the 'exponent' term accounts for the shifts during divide] */ +	if (var1initpad<postshift) postshift=var1initpad; + +	/* shift var1 the requested amount, and adjust its digits */ +	var1units=decShiftToLeast(var1, var1units, postshift); +	accnext=var1; +	accdigits=decGetDigits(var1, var1units); +	accunits=D2U(accdigits); + +	exponent=lhs->exponent;		/* exponent is smaller of lhs & rhs */ +	if (rhs->exponent<exponent) exponent=rhs->exponent; + +	/* Now correct the result if doing remainderNear; if it */ +	/* (looking just at coefficients) is > rhs/2, or == rhs/2 and */ +	/* the integer was odd then the result should be rem-rhs. */ +	if (op&REMNEAR) { +	  Int compare, tarunits;	/* work */ +	  Unit *up;			/* .. */ +	  /* calculate remainder*2 into the var1 buffer (which has */ +	  /* 'headroom' of an extra unit and hence enough space) */ +	  /* [a dedicated 'double' loop would be faster, here] */ +	  tarunits=decUnitAddSub(accnext, accunits, accnext, accunits, +				 0, accnext, 1); +	  /* decDumpAr('r', accnext, tarunits); */ + +	  /* Here, accnext (var1) holds tarunits Units with twice the */ +	  /* remainder's coefficient, which must now be compared to the */ +	  /* RHS.  The remainder's exponent may be smaller than the RHS's. */ +	  compare=decUnitCompare(accnext, tarunits, rhs->lsu, D2U(rhs->digits), +				 rhs->exponent-exponent); +	  if (compare==BADINT) {	     /* deep trouble */ +	    *status|=DEC_Insufficient_storage; +	    break;} + +	  /* now restore the remainder by dividing by two; the lsu */ +	  /* is known to be even. */ +	  for (up=accnext; up<accnext+tarunits; up++) { +	    Int half;		   /* half to add to lower unit */ +	    half=*up & 0x01; +	    *up/=2;		   /* [shift] */ +	    if (!half) continue; +	    *(up-1)+=(DECDPUNMAX+1)/2; +	    } +	  /* [accunits still describes the original remainder length] */ + +	  if (compare>0 || (compare==0 && wasodd)) { /* adjustment needed */ +	    Int exp, expunits, exprem;	     /* work */ +	    /* This is effectively causing round-up of the quotient, */ +	    /* so if it was the rare case where it was full and all */ +	    /* nines, it would overflow and hence division-impossible */ +	    /* should be raised */ +	    Flag allnines=0;		     /* 1 if quotient all nines */ +	    if (quotdigits==reqdigits) {     /* could be borderline */ +	      for (up=quotlsu; ; up++) { +		if (quotdigits>DECDPUN) { +		  if (*up!=DECDPUNMAX) break;/* non-nines */ +		  } +		 else {			     /* this is the last Unit */ +		  if (*up==powers[quotdigits]-1) allnines=1; +		  break; +		  } +		quotdigits-=DECDPUN;	     /* checked those digits */ +		} /* up */ +	      } /* borderline check */ +	    if (allnines) { +	      *status|=DEC_Division_impossible; +	      break;} + +	    /* rem-rhs is needed; the sign will invert.	 Again, var1 */ +	    /* can safely be used for the working Units array. */ +	    exp=rhs->exponent-exponent;	     /* RHS padding needed */ +	    /* Calculate units and remainder from exponent. */ +	    expunits=exp/DECDPUN; +	    exprem=exp%DECDPUN; +	    /* subtract [A+B*(-m)]; the result will always be negative */ +	    accunits=-decUnitAddSub(accnext, accunits, +				    rhs->lsu, D2U(rhs->digits), +				    expunits, accnext, -(Int)powers[exprem]); +	    accdigits=decGetDigits(accnext, accunits); /* count digits exactly */ +	    accunits=D2U(accdigits);	/* and recalculate the units for copy */ +	    /* [exponent is as for original remainder] */ +	    bits^=DECNEG;		/* flip the sign */ +	    } +	  } /* REMNEAR */ +	} /* REMAINDER or REMNEAR */ +      } /* not DIVIDE */ + +    /* Set exponent and bits */ +    res->exponent=exponent; +    res->bits=(uByte)(bits&DECNEG);	     /* [cleaned] */ + +    /* Now the coefficient. */ +    decSetCoeff(res, set, accnext, accdigits, &residue, status); + +    decFinish(res, set, &residue, status);   /* final cleanup */ + +    #if DECSUBSET +    /* If a divide then strip trailing zeros if subset [after round] */ +    if (!set->extended && (op==DIVIDE)) decTrim(res, set, 0, &dropped); +    #endif +    } while(0);				     /* end protected */ + +  if (varalloc!=NULL) free(varalloc);	/* drop any storage used */ +  if (allocacc!=NULL) free(allocacc);	/* .. */ +  #if DECSUBSET +  if (allocrhs!=NULL) free(allocrhs);	/* .. */ +  if (alloclhs!=NULL) free(alloclhs);	/* .. */ +  #endif +  return res; +  } /* decDivideOp */ + +/* ------------------------------------------------------------------ */ +/* decMultiplyOp -- multiplication operation			      */ +/*								      */ +/*  This routine performs the multiplication C=A x B.		      */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X*X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*   status is the usual accumulator				      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* ------------------------------------------------------------------ */ +/* 'Classic' multiplication is used rather than Karatsuba, as the     */ +/* latter would give only a minor improvement for the short numbers   */ +/* expected to be handled most (and uses much more memory).	      */ +/*								      */ +/* There are two major paths here: the general-purpose ('old code')   */ +/* path which handles all DECDPUN values, and a fastpath version      */ +/* which is used if 64-bit ints are available, DECDPUN<=4, and more   */ +/* than two calls to decUnitAddSub would be made.		      */ +/*								      */ +/* The fastpath version lumps units together into 8-digit or 9-digit  */ +/* chunks, and also uses a lazy carry strategy to minimise expensive  */ +/* 64-bit divisions.  The chunks are then broken apart again into     */ +/* units for continuing processing.  Despite this overhead, the	      */ +/* fastpath can speed up some 16-digit operations by 10x (and much    */ +/* more for higher-precision calculations).			      */ +/*								      */ +/* A buffer always has to be used for the accumulator; in the	      */ +/* fastpath, buffers are also always needed for the chunked copies of */ +/* of the operand coefficients.					      */ +/* Static buffers are larger than needed just for multiply, to allow  */ +/* for calls from other operations (notably exp).		      */ +/* ------------------------------------------------------------------ */ +#define FASTMUL (DECUSE64 && DECDPUN<5) +static decNumber * decMultiplyOp(decNumber *res, const decNumber *lhs, +				 const decNumber *rhs, decContext *set, +				 uInt *status) { +  Int	 accunits;		   /* Units of accumulator in use */ +  Int	 exponent;		   /* work */ +  Int	 residue=0;		   /* rounding residue */ +  uByte	 bits;			   /* result sign */ +  Unit	*acc;			   /* -> accumulator Unit array */ +  Int	 needbytes;		   /* size calculator */ +  void	*allocacc=NULL;		   /* -> allocated accumulator, iff allocated */ +  Unit	accbuff[SD2U(DECBUFFER*4+1)]; /* buffer (+1 for DECBUFFER==0, */ +				   /* *4 for calls from other operations) */ +  const Unit *mer, *mermsup;	   /* work */ +  Int	madlength;		   /* Units in multiplicand */ +  Int	shift;			   /* Units to shift multiplicand by */ + +  #if FASTMUL +    /* if DECDPUN is 1 or 3 work in base 10**9, otherwise */ +    /* (DECDPUN is 2 or 4) then work in base 10**8 */ +    #if DECDPUN & 1		   /* odd */ +      #define FASTBASE 1000000000  /* base */ +      #define FASTDIGS		9  /* digits in base */ +      #define FASTLAZY	       18  /* carry resolution point [1->18] */ +    #else +      #define FASTBASE	100000000 +      #define FASTDIGS		8 +      #define FASTLAZY	     1844  /* carry resolution point [1->1844] */ +    #endif +    /* three buffers are used, two for chunked copies of the operands */ +    /* (base 10**8 or base 10**9) and one base 2**64 accumulator with */ +    /* lazy carry evaluation */ +    uInt   zlhibuff[(DECBUFFER*2+1)/8+1]; /* buffer (+1 for DECBUFFER==0) */ +    uInt  *zlhi=zlhibuff;		  /* -> lhs array */ +    uInt  *alloclhi=NULL;		  /* -> allocated buffer, iff allocated */ +    uInt   zrhibuff[(DECBUFFER*2+1)/8+1]; /* buffer (+1 for DECBUFFER==0) */ +    uInt  *zrhi=zrhibuff;		  /* -> rhs array */ +    uInt  *allocrhi=NULL;		  /* -> allocated buffer, iff allocated */ +    uLong  zaccbuff[(DECBUFFER*2+1)/4+2]; /* buffer (+1 for DECBUFFER==0) */ +    /* [allocacc is shared for both paths, as only one will run] */ +    uLong *zacc=zaccbuff;	   /* -> accumulator array for exact result */ +    #if DECDPUN==1 +    Int	   zoff;		   /* accumulator offset */ +    #endif +    uInt  *lip, *rip;		   /* item pointers */ +    uInt  *lmsi, *rmsi;		   /* most significant items */ +    Int	   ilhs, irhs, iacc;	   /* item counts in the arrays */ +    Int	   lazy;		   /* lazy carry counter */ +    uLong  lcarry;		   /* uLong carry */ +    uInt   carry;		   /* carry (NB not uLong) */ +    Int	   count;		   /* work */ +    const  Unit *cup;		   /* .. */ +    Unit  *up;			   /* .. */ +    uLong *lp;			   /* .. */ +    Int	   p;			   /* .. */ +  #endif + +  #if DECSUBSET +    decNumber *alloclhs=NULL;	   /* -> allocated buffer, iff allocated */ +    decNumber *allocrhs=NULL;	   /* -> allocated buffer, iff allocated */ +  #endif + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  /* precalculate result sign */ +  bits=(uByte)((lhs->bits^rhs->bits)&DECNEG); + +  /* handle infinities and NaNs */ +  if (SPECIALARGS) {		   /* a special bit set */ +    if (SPECIALARGS & (DECSNAN | DECNAN)) { /* one or two NaNs */ +      decNaNs(res, lhs, rhs, set, status); +      return res;} +    /* one or two infinities; Infinity * 0 is invalid */ +    if (((lhs->bits & DECINF)==0 && ISZERO(lhs)) +      ||((rhs->bits & DECINF)==0 && ISZERO(rhs))) { +      *status|=DEC_Invalid_operation; +      return res;} +    decNumberZero(res); +    res->bits=bits|DECINF;	   /* infinity */ +    return res;} + +  /* For best speed, as in DMSRCN [the original Rexx numerics */ +  /* module], use the shorter number as the multiplier (rhs) and */ +  /* the longer as the multiplicand (lhs) to minimise the number of */ +  /* adds (partial products) */ +  if (lhs->digits<rhs->digits) {   /* swap... */ +    const decNumber *hold=lhs; +    lhs=rhs; +    rhs=hold; +    } + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operands and set lostDigits status, as needed */ +      if (lhs->digits>set->digits) { +	alloclhs=decRoundOperand(lhs, set, status); +	if (alloclhs==NULL) break; +	lhs=alloclhs; +	} +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    #if FASTMUL			   /* fastpath can be used */ +    /* use the fast path if there are enough digits in the shorter */ +    /* operand to make the setup and takedown worthwhile */ +    #define NEEDTWO (DECDPUN*2)	   /* within two decUnitAddSub calls */ +    if (rhs->digits>NEEDTWO) {	   /* use fastpath... */ +      /* calculate the number of elements in each array */ +      ilhs=(lhs->digits+FASTDIGS-1)/FASTDIGS; /* [ceiling] */ +      irhs=(rhs->digits+FASTDIGS-1)/FASTDIGS; /* .. */ +      iacc=ilhs+irhs; + +      /* allocate buffers if required, as usual */ +      needbytes=ilhs*sizeof(uInt); +      if (needbytes>(Int)sizeof(zlhibuff)) { +	alloclhi=(uInt *)malloc(needbytes); +	zlhi=alloclhi;} +      needbytes=irhs*sizeof(uInt); +      if (needbytes>(Int)sizeof(zrhibuff)) { +	allocrhi=(uInt *)malloc(needbytes); +	zrhi=allocrhi;} + +      /* Allocating the accumulator space needs a special case when */ +      /* DECDPUN=1 because when converting the accumulator to Units */ +      /* after the multiplication each 8-byte item becomes 9 1-byte */ +      /* units.	 Therefore iacc extra bytes are needed at the front */ +      /* (rounded up to a multiple of 8 bytes), and the uLong */ +      /* accumulator starts offset the appropriate number of units */ +      /* to the right to avoid overwrite during the unchunking. */ +      needbytes=iacc*sizeof(uLong); +      #if DECDPUN==1 +      zoff=(iacc+7)/8;	      /* items to offset by */ +      needbytes+=zoff*8; +      #endif +      if (needbytes>(Int)sizeof(zaccbuff)) { +	allocacc=(uLong *)malloc(needbytes); +	zacc=(uLong *)allocacc;} +      if (zlhi==NULL||zrhi==NULL||zacc==NULL) { +	*status|=DEC_Insufficient_storage; +	break;} + +      acc=(Unit *)zacc;	      /* -> target Unit array */ +      #if DECDPUN==1 +      zacc+=zoff;	      /* start uLong accumulator to right */ +      #endif + +      /* assemble the chunked copies of the left and right sides */ +      for (count=lhs->digits, cup=lhs->lsu, lip=zlhi; count>0; lip++) +	for (p=0, *lip=0; p<FASTDIGS && count>0; +	     p+=DECDPUN, cup++, count-=DECDPUN) +	  *lip+=*cup*powers[p]; +      lmsi=lip-1;     /* save -> msi */ +      for (count=rhs->digits, cup=rhs->lsu, rip=zrhi; count>0; rip++) +	for (p=0, *rip=0; p<FASTDIGS && count>0; +	     p+=DECDPUN, cup++, count-=DECDPUN) +	  *rip+=*cup*powers[p]; +      rmsi=rip-1;     /* save -> msi */ + +      /* zero the accumulator */ +      for (lp=zacc; lp<zacc+iacc; lp++) *lp=0; + +      /* Start the multiplication */ +      /* Resolving carries can dominate the cost of accumulating the */ +      /* partial products, so this is only done when necessary. */ +      /* Each uLong item in the accumulator can hold values up to */ +      /* 2**64-1, and each partial product can be as large as */ +      /* (10**FASTDIGS-1)**2.  When FASTDIGS=9, this can be added to */ +      /* itself 18.4 times in a uLong without overflowing, so during */ +      /* the main calculation resolution is carried out every 18th */ +      /* add -- every 162 digits.  Similarly, when FASTDIGS=8, the */ +      /* partial products can be added to themselves 1844.6 times in */ +      /* a uLong without overflowing, so intermediate carry */ +      /* resolution occurs only every 14752 digits.  Hence for common */ +      /* short numbers usually only the one final carry resolution */ +      /* occurs. */ +      /* (The count is set via FASTLAZY to simplify experiments to */ +      /* measure the value of this approach: a 35% improvement on a */ +      /* [34x34] multiply.) */ +      lazy=FASTLAZY;			     /* carry delay count */ +      for (rip=zrhi; rip<=rmsi; rip++) {     /* over each item in rhs */ +	lp=zacc+(rip-zrhi);		     /* where to add the lhs */ +	for (lip=zlhi; lip<=lmsi; lip++, lp++) { /* over each item in lhs */ +	  *lp+=(uLong)(*lip)*(*rip);	     /* [this should in-line] */ +	  } /* lip loop */ +	lazy--; +	if (lazy>0 && rip!=rmsi) continue; +	lazy=FASTLAZY;			     /* reset delay count */ +	/* spin up the accumulator resolving overflows */ +	for (lp=zacc; lp<zacc+iacc; lp++) { +	  if (*lp<FASTBASE) continue;	     /* it fits */ +	  lcarry=*lp/FASTBASE;		     /* top part [slow divide] */ +	  /* lcarry can exceed 2**32-1, so check again; this check */ +	  /* and occasional extra divide (slow) is well worth it, as */ +	  /* it allows FASTLAZY to be increased to 18 rather than 4 */ +	  /* in the FASTDIGS=9 case */ +	  if (lcarry<FASTBASE) carry=(uInt)lcarry;  /* [usual] */ +	   else { /* two-place carry [fairly rare] */ +	    uInt carry2=(uInt)(lcarry/FASTBASE);    /* top top part */ +	    *(lp+2)+=carry2;			    /* add to item+2 */ +	    *lp-=((uLong)FASTBASE*FASTBASE*carry2); /* [slow] */ +	    carry=(uInt)(lcarry-((uLong)FASTBASE*carry2)); /* [inline] */ +	    } +	  *(lp+1)+=carry;		     /* add to item above [inline] */ +	  *lp-=((uLong)FASTBASE*carry);	     /* [inline] */ +	  } /* carry resolution */ +	} /* rip loop */ + +      /* The multiplication is complete; time to convert back into */ +      /* units.	 This can be done in-place in the accumulator and in */ +      /* 32-bit operations, because carries were resolved after the */ +      /* final add.  This needs N-1 divides and multiplies for */ +      /* each item in the accumulator (which will become up to N */ +      /* units, where 2<=N<=9). */ +      for (lp=zacc, up=acc; lp<zacc+iacc; lp++) { +	uInt item=(uInt)*lp;		     /* decapitate to uInt */ +	for (p=0; p<FASTDIGS-DECDPUN; p+=DECDPUN, up++) { +	  uInt part=item/(DECDPUNMAX+1); +	  *up=(Unit)(item-(part*(DECDPUNMAX+1))); +	  item=part; +	  } /* p */ +	*up=(Unit)item; up++;		     /* [final needs no division] */ +	} /* lp */ +      accunits=up-acc;			     /* count of units */ +      } +     else { /* here to use units directly, without chunking ['old code'] */ +    #endif + +      /* if accumulator will be too long for local storage, then allocate */ +      acc=accbuff;		   /* -> assume buffer for accumulator */ +      needbytes=(D2U(lhs->digits)+D2U(rhs->digits))*sizeof(Unit); +      if (needbytes>(Int)sizeof(accbuff)) { +	allocacc=(Unit *)malloc(needbytes); +	if (allocacc==NULL) {*status|=DEC_Insufficient_storage; break;} +	acc=(Unit *)allocacc;		     /* use the allocated space */ +	} + +      /* Now the main long multiplication loop */ +      /* Unlike the equivalent in the IBM Java implementation, there */ +      /* is no advantage in calculating from msu to lsu.  So, do it */ +      /* by the book, as it were. */ +      /* Each iteration calculates ACC=ACC+MULTAND*MULT */ +      accunits=1;		   /* accumulator starts at '0' */ +      *acc=0;			   /* .. (lsu=0) */ +      shift=0;			   /* no multiplicand shift at first */ +      madlength=D2U(lhs->digits);  /* this won't change */ +      mermsup=rhs->lsu+D2U(rhs->digits); /* -> msu+1 of multiplier */ + +      for (mer=rhs->lsu; mer<mermsup; mer++) { +	/* Here, *mer is the next Unit in the multiplier to use */ +	/* If non-zero [optimization] add it... */ +	if (*mer!=0) accunits=decUnitAddSub(&acc[shift], accunits-shift, +					    lhs->lsu, madlength, 0, +					    &acc[shift], *mer) +					    + shift; +	 else { /* extend acc with a 0; it will be used shortly */ +	  *(acc+accunits)=0;	   /* [this avoids length of <=0 later] */ +	  accunits++; +	  } +	/* multiply multiplicand by 10**DECDPUN for next Unit to left */ +	shift++;		   /* add this for 'logical length' */ +	} /* n */ +    #if FASTMUL +      } /* unchunked units */ +    #endif +    /* common end-path */ +    #if DECTRACE +      decDumpAr('*', acc, accunits);	     /* Show exact result */ +    #endif + +    /* acc now contains the exact result of the multiplication, */ +    /* possibly with a leading zero unit; build the decNumber from */ +    /* it, noting if any residue */ +    res->bits=bits;			     /* set sign */ +    res->digits=decGetDigits(acc, accunits); /* count digits exactly */ + +    /* There can be a 31-bit wrap in calculating the exponent. */ +    /* This can only happen if both input exponents are negative and */ +    /* both their magnitudes are large.	 If there was a wrap, set a */ +    /* safe very negative exponent, from which decFinalize() will */ +    /* raise a hard underflow shortly. */ +    exponent=lhs->exponent+rhs->exponent;    /* calculate exponent */ +    if (lhs->exponent<0 && rhs->exponent<0 && exponent>0) +      exponent=-2*DECNUMMAXE;		     /* force underflow */ +    res->exponent=exponent;		     /* OK to overwrite now */ + + +    /* Set the coefficient.  If any rounding, residue records */ +    decSetCoeff(res, set, acc, res->digits, &residue, status); +    decFinish(res, set, &residue, status);   /* final cleanup */ +    } while(0);				/* end protected */ + +  if (allocacc!=NULL) free(allocacc);	/* drop any storage used */ +  #if DECSUBSET +  if (allocrhs!=NULL) free(allocrhs);	/* .. */ +  if (alloclhs!=NULL) free(alloclhs);	/* .. */ +  #endif +  #if FASTMUL +  if (allocrhi!=NULL) free(allocrhi);	/* .. */ +  if (alloclhi!=NULL) free(alloclhi);	/* .. */ +  #endif +  return res; +  } /* decMultiplyOp */ + +/* ------------------------------------------------------------------ */ +/* decExpOp -- effect exponentiation				      */ +/*								      */ +/*   This computes C = exp(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits. status is updated but    */ +/* not set.							      */ +/*								      */ +/* Restrictions:						      */ +/*								      */ +/*   digits, emax, and -emin in the context must be less than	      */ +/*   2*DEC_MAX_MATH (1999998), and the rhs must be within these	      */ +/*   bounds or a zero.	This is an internal routine, so these	      */ +/*   restrictions are contractual and not enforced.		      */ +/*								      */ +/* A finite result is rounded using DEC_ROUND_HALF_EVEN; it will      */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/*								      */ +/* Finite results will always be full precision and Inexact, except   */ +/* when A is a zero or -Infinity (giving 1 or 0 respectively).	      */ +/* ------------------------------------------------------------------ */ +/* This approach used here is similar to the algorithm described in   */ +/*								      */ +/*   Variable Precision Exponential Function, T. E. Hull and	      */ +/*   A. Abrham, ACM Transactions on Mathematical Software, Vol 12 #2, */ +/*   pp79-91, ACM, June 1986.					      */ +/*								      */ +/* with the main difference being that the iterations in the series   */ +/* evaluation are terminated dynamically (which does not require the  */ +/* extra variable-precision variables which are expensive in this     */ +/* context).							      */ +/*								      */ +/* The error analysis in Hull & Abrham's paper applies except for the */ +/* round-off error accumulation during the series evaluation.  This   */ +/* code does not precalculate the number of iterations and so cannot  */ +/* use Horner's scheme.	 Instead, the accumulation is done at double- */ +/* precision, which ensures that the additions of the terms are exact */ +/* and do not accumulate round-off (and any round-off errors in the   */ +/* terms themselves move 'to the right' faster than they can	      */ +/* accumulate).	 This code also extends the calculation by allowing,  */ +/* in the spirit of other decNumber operators, the input to be more   */ +/* precise than the result (the precision used is based on the more   */ +/* precise of the input or requested result).			      */ +/*								      */ +/* Implementation notes:					      */ +/*								      */ +/* 1. This is separated out as decExpOp so it can be called from      */ +/*    other Mathematical functions (notably Ln) with a wider range    */ +/*    than normal.  In particular, it can handle the slightly wider   */ +/*    (double) range needed by Ln (which has to be able to calculate  */ +/*    exp(-x) where x can be the tiniest number (Ntiny).	      */ +/*								      */ +/* 2. Normalizing x to be <=0.1 (instead of <=1) reduces loop	      */ +/*    iterations by appoximately a third with additional (although    */ +/*    diminishing) returns as the range is reduced to even smaller    */ +/*    fractions.  However, h (the power of 10 used to correct the     */ +/*    result at the end, see below) must be kept <=8 as otherwise     */ +/*    the final result cannot be computed.  Hence the leverage is a   */ +/*    sliding value (8-h), where potentially the range is reduced     */ +/*    more for smaller values.					      */ +/*								      */ +/*    The leverage that can be applied in this way is severely	      */ +/*    limited by the cost of the raise-to-the power at the end,	      */ +/*    which dominates when the number of iterations is small (less    */ +/*    than ten) or when rhs is short.  As an example, the adjustment  */ +/*    x**10,000,000 needs 31 multiplications, all but one full-width. */ +/*								      */ +/* 3. The restrictions (especially precision) could be raised with    */ +/*    care, but the full decNumber range seems very hard within the   */ +/*    32-bit limits.						      */ +/*								      */ +/* 4. The working precisions for the static buffers are twice the     */ +/*    obvious size to allow for calls from decNumberPower.	      */ +/* ------------------------------------------------------------------ */ +static decNumber *decExpOp(decNumber *res, const decNumber *rhs, +                           decContext *set, uInt *status) { +  uInt ignore=0;		   /* working status */ +  Int h;			   /* adjusted exponent for 0.xxxx */ +  Int p;			   /* working precision */ +  Int residue;			   /* rounding residue */ +  uInt needbytes;		   /* for space calculations */ +  const decNumber *x=rhs;	   /* (may point to safe copy later) */ +  decContext aset, tset, dset;	   /* working contexts */ +  Int comp;			   /* work */ + +  /* the argument is often copied to normalize it, so (unusually) it */ +  /* is treated like other buffers, using DECBUFFER, +1 in case */ +  /* DECBUFFER is 0 */ +  decNumber bufr[D2N(DECBUFFER*2+1)]; +  decNumber *allocrhs=NULL;	   /* non-NULL if rhs buffer allocated */ + +  /* the working precision will be no more than set->digits+8+1 */ +  /* so for on-stack buffers DECBUFFER+9 is used, +1 in case DECBUFFER */ +  /* is 0 (and twice that for the accumulator) */ + +  /* buffer for t, term (working precision plus) */ +  decNumber buft[D2N(DECBUFFER*2+9+1)]; +  decNumber *allocbuft=NULL;	   /* -> allocated buft, iff allocated */ +  decNumber *t=buft;		   /* term */ +  /* buffer for a, accumulator (working precision * 2), at least 9 */ +  decNumber bufa[D2N(DECBUFFER*4+18+1)]; +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *a=bufa;		   /* accumulator */ +  /* decNumber for the divisor term; this needs at most 9 digits */ +  /* and so can be fixed size [16 so can use standard context] */ +  decNumber bufd[D2N(16)]; +  decNumber *d=bufd;		   /* divisor */ +  decNumber numone;		   /* constant 1 */ + +  #if DECCHECK +  Int iterations=0;		   /* for later sanity check */ +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  do {					/* protect allocated storage */ +    if (SPECIALARG) {			/* handle infinities and NaNs */ +      if (decNumberIsInfinite(rhs)) {	/* an infinity */ +	if (decNumberIsNegative(rhs))	/* -Infinity -> +0 */ +	  decNumberZero(res); +	 else decNumberCopy(res, rhs);	/* +Infinity -> self */ +	} +       else decNaNs(res, rhs, NULL, set, status); /* a NaN */ +      break;} + +    if (ISZERO(rhs)) {			/* zeros -> exact 1 */ +      decNumberZero(res);		/* make clean 1 */ +      *res->lsu=1;			/* .. */ +      break;}				/* [no status to set] */ + +    /* e**x when 0 < x < 0.66 is < 1+3x/2, hence can fast-path */ +    /* positive and negative tiny cases which will result in inexact */ +    /* 1.  This also allows the later add-accumulate to always be */ +    /* exact (because its length will never be more than twice the */ +    /* working precision). */ +    /* The comparator (tiny) needs just one digit, so use the */ +    /* decNumber d for it (reused as the divisor, etc., below); its */ +    /* exponent is such that if x is positive it will have */ +    /* set->digits-1 zeros between the decimal point and the digit, */ +    /* which is 4, and if x is negative one more zero there as the */ +    /* more precise result will be of the form 0.9999999 rather than */ +    /* 1.0000001.  Hence, tiny will be 0.0000004  if digits=7 and x>0 */ +    /* or 0.00000004 if digits=7 and x<0.  If RHS not larger than */ +    /* this then the result will be 1.000000 */ +    decNumberZero(d);			/* clean */ +    *d->lsu=4;				/* set 4 .. */ +    d->exponent=-set->digits;		/* * 10**(-d) */ +    if (decNumberIsNegative(rhs)) d->exponent--;  /* negative case */ +    comp=decCompare(d, rhs, 1);		/* signless compare */ +    if (comp==BADINT) { +      *status|=DEC_Insufficient_storage; +      break;} +    if (comp>=0) {			/* rhs < d */ +      Int shift=set->digits-1; +      decNumberZero(res);		/* set 1 */ +      *res->lsu=1;			/* .. */ +      res->digits=decShiftToMost(res->lsu, 1, shift); +      res->exponent=-shift;		     /* make 1.0000... */ +      *status|=DEC_Inexact | DEC_Rounded;    /* .. inexactly */ +      break;} /* tiny */ + +    /* set up the context to be used for calculating a, as this is */ +    /* used on both paths below */ +    decContextDefault(&aset, DEC_INIT_DECIMAL64); +    /* accumulator bounds are as requested (could underflow) */ +    aset.emax=set->emax;		/* usual bounds */ +    aset.emin=set->emin;		/* .. */ +    aset.clamp=0;			/* and no concrete format */ + +    /* calculate the adjusted (Hull & Abrham) exponent (where the */ +    /* decimal point is just to the left of the coefficient msd) */ +    h=rhs->exponent+rhs->digits; +    /* if h>8 then 10**h cannot be calculated safely; however, when */ +    /* h=8 then exp(|rhs|) will be at least exp(1E+7) which is at */ +    /* least 6.59E+4342944, so (due to the restriction on Emax/Emin) */ +    /* overflow (or underflow to 0) is guaranteed -- so this case can */ +    /* be handled by simply forcing the appropriate excess */ +    if (h>8) {				/* overflow/underflow */ +      /* set up here so Power call below will over or underflow to */ +      /* zero; set accumulator to either 2 or 0.02 */ +      /* [stack buffer for a is always big enough for this] */ +      decNumberZero(a); +      *a->lsu=2;			/* not 1 but < exp(1) */ +      if (decNumberIsNegative(rhs)) a->exponent=-2; /* make 0.02 */ +      h=8;				/* clamp so 10**h computable */ +      p=9;				/* set a working precision */ +      } +     else {				/* h<=8 */ +      Int maxlever=(rhs->digits>8?1:0); +      /* [could/should increase this for precisions >40 or so, too] */ + +      /* if h is 8, cannot normalize to a lower upper limit because */ +      /* the final result will not be computable (see notes above), */ +      /* but leverage can be applied whenever h is less than 8. */ +      /* Apply as much as possible, up to a MAXLEVER digits, which */ +      /* sets the tradeoff against the cost of the later a**(10**h). */ +      /* As h is increased, the working precision below also */ +      /* increases to compensate for the "constant digits at the */ +      /* front" effect. */ +      Int lever=MINI(8-h, maxlever);	/* leverage attainable */ +      Int use=-rhs->digits-lever;	/* exponent to use for RHS */ +      h+=lever;				/* apply leverage selected */ +      if (h<0) {			/* clamp */ +	use+=h;				/* [may end up subnormal] */ +	h=0; +	} +      /* Take a copy of RHS if it needs normalization (true whenever x>=1) */ +      if (rhs->exponent!=use) { +	decNumber *newrhs=bufr;		/* assume will fit on stack */ +	needbytes=sizeof(decNumber)+(D2U(rhs->digits)-1)*sizeof(Unit); +	if (needbytes>sizeof(bufr)) {	/* need malloc space */ +	  allocrhs=(decNumber *)malloc(needbytes); +	  if (allocrhs==NULL) {		/* hopeless -- abandon */ +	    *status|=DEC_Insufficient_storage; +	    break;} +	  newrhs=allocrhs;		/* use the allocated space */ +	  } +	decNumberCopy(newrhs, rhs);	/* copy to safe space */ +	newrhs->exponent=use;		/* normalize; now <1 */ +	x=newrhs;			/* ready for use */ +	/* decNumberShow(x); */ +	} + +      /* Now use the usual power series to evaluate exp(x).  The */ +      /* series starts as 1 + x + x^2/2 ... so prime ready for the */ +      /* third term by setting the term variable t=x, the accumulator */ +      /* a=1, and the divisor d=2. */ + +      /* First determine the working precision.	 From Hull & Abrham */ +      /* this is set->digits+h+2.  However, if x is 'over-precise' we */ +      /* need to allow for all its digits to potentially participate */ +      /* (consider an x where all the excess digits are 9s) so in */ +      /* this case use x->digits+h+2 */ +      p=MAXI(x->digits, set->digits)+h+2;    /* [h<=8] */ + +      /* a and t are variable precision, and depend on p, so space */ +      /* must be allocated for them if necessary */ + +      /* the accumulator needs to be able to hold 2p digits so that */ +      /* the additions on the second and subsequent iterations are */ +      /* sufficiently exact. */ +      needbytes=sizeof(decNumber)+(D2U(p*2)-1)*sizeof(Unit); +      if (needbytes>sizeof(bufa)) {	/* need malloc space */ +	allocbufa=(decNumber *)malloc(needbytes); +	if (allocbufa==NULL) {		/* hopeless -- abandon */ +	  *status|=DEC_Insufficient_storage; +	  break;} +	a=allocbufa;			/* use the allocated space */ +	} +      /* the term needs to be able to hold p digits (which is */ +      /* guaranteed to be larger than x->digits, so the initial copy */ +      /* is safe); it may also be used for the raise-to-power */ +      /* calculation below, which needs an extra two digits */ +      needbytes=sizeof(decNumber)+(D2U(p+2)-1)*sizeof(Unit); +      if (needbytes>sizeof(buft)) {	/* need malloc space */ +	allocbuft=(decNumber *)malloc(needbytes); +	if (allocbuft==NULL) {		/* hopeless -- abandon */ +	  *status|=DEC_Insufficient_storage; +	  break;} +	t=allocbuft;			/* use the allocated space */ +	} + +      decNumberCopy(t, x);		/* term=x */ +      decNumberZero(a); *a->lsu=1;	/* accumulator=1 */ +      decNumberZero(d); *d->lsu=2;	/* divisor=2 */ +      decNumberZero(&numone); *numone.lsu=1; /* constant 1 for increment */ + +      /* set up the contexts for calculating a, t, and d */ +      decContextDefault(&tset, DEC_INIT_DECIMAL64); +      dset=tset; +      /* accumulator bounds are set above, set precision now */ +      aset.digits=p*2;			/* double */ +      /* term bounds avoid any underflow or overflow */ +      tset.digits=p; +      tset.emin=DEC_MIN_EMIN;		/* [emax is plenty] */ +      /* [dset.digits=16, etc., are sufficient] */ + +      /* finally ready to roll */ +      for (;;) { +	#if DECCHECK +	iterations++; +	#endif +	/* only the status from the accumulation is interesting */ +	/* [but it should remain unchanged after first add] */ +	decAddOp(a, a, t, &aset, 0, status);	       /* a=a+t */ +	decMultiplyOp(t, t, x, &tset, &ignore);	       /* t=t*x */ +	decDivideOp(t, t, d, &tset, DIVIDE, &ignore);  /* t=t/d */ +	/* the iteration ends when the term cannot affect the result, */ +	/* if rounded to p digits, which is when its value is smaller */ +	/* than the accumulator by p+1 digits.	There must also be */ +	/* full precision in a. */ +	if (((a->digits+a->exponent)>=(t->digits+t->exponent+p+1)) +	    && (a->digits>=p)) break; +	decAddOp(d, d, &numone, &dset, 0, &ignore);    /* d=d+1 */ +	} /* iterate */ + +      #if DECCHECK +      /* just a sanity check; comment out test to show always */ +      if (iterations>p+3) +	printf("Exp iterations=%ld, status=%08lx, p=%ld, d=%ld\n", +	       iterations, *status, p, x->digits); +      #endif +      } /* h<=8 */ + +    /* apply postconditioning: a=a**(10**h) -- this is calculated */ +    /* at a slightly higher precision than Hull & Abrham suggest */ +    if (h>0) { +      Int seenbit=0;		   /* set once a 1-bit is seen */ +      Int i;			   /* counter */ +      Int n=powers[h];		   /* always positive */ +      aset.digits=p+2;		   /* sufficient precision */ +      /* avoid the overhead and many extra digits of decNumberPower */ +      /* as all that is needed is the short 'multipliers' loop; here */ +      /* accumulate the answer into t */ +      decNumberZero(t); *t->lsu=1; /* acc=1 */ +      for (i=1;;i++){		   /* for each bit [top bit ignored] */ +	/* abandon if have had overflow or terminal underflow */ +	if (*status & (DEC_Overflow|DEC_Underflow)) { /* interesting? */ +	  if (*status&DEC_Overflow || ISZERO(t)) break;} +	n=n<<1;			   /* move next bit to testable position */ +	if (n<0) {		   /* top bit is set */ +	  seenbit=1;		   /* OK, have a significant bit */ +	  decMultiplyOp(t, t, a, &aset, status); /* acc=acc*x */ +	  } +	if (i==31) break;	   /* that was the last bit */ +	if (!seenbit) continue;	   /* no need to square 1 */ +	decMultiplyOp(t, t, t, &aset, status); /* acc=acc*acc [square] */ +	} /*i*/ /* 32 bits */ +      /* decNumberShow(t); */ +      a=t;			   /* and carry on using t instead of a */ +      } + +    /* Copy and round the result to res */ +    residue=1;				/* indicate dirt to right .. */ +    if (ISZERO(a)) residue=0;		/* .. unless underflowed to 0 */ +    aset.digits=set->digits;		/* [use default rounding] */ +    decCopyFit(res, a, &aset, &residue, status); /* copy & shorten */ +    decFinish(res, set, &residue, status);	 /* cleanup/set flags */ +    } while(0);				/* end protected */ + +  if (allocrhs !=NULL) free(allocrhs);	/* drop any storage used */ +  if (allocbufa!=NULL) free(allocbufa); /* .. */ +  if (allocbuft!=NULL) free(allocbuft); /* .. */ +  /* [status is handled by caller] */ +  return res; +  } /* decExpOp */ + +/* ------------------------------------------------------------------ */ +/* Initial-estimate natural logarithm table			      */ +/*								      */ +/*   LNnn -- 90-entry 16-bit table for values from .10 through .99.   */ +/*	     The result is a 4-digit encode of the coefficient (c=the */ +/*	     top 14 bits encoding 0-9999) and a 2-digit encode of the */ +/*	     exponent (e=the bottom 2 bits encoding 0-3)	      */ +/*								      */ +/*	     The resulting value is given by:			      */ +/*								      */ +/*	       v = -c * 10**(-e-3)				      */ +/*								      */ +/*	     where e and c are extracted from entry k = LNnn[x-10]    */ +/*	     where x is truncated (NB) into the range 10 through 99,  */ +/*	     and then c = k>>2 and e = k&3.			      */ +/* ------------------------------------------------------------------ */ +static const uShort LNnn[90] = { +  9016,  8652,  8316,  8008,  7724,  7456,  7208, +  6972,	 6748,	6540,  6340,  6148,  5968,  5792,  5628,  5464,	 5312, +  5164,	 5020,	4884,  4748,  4620,  4496,  4376,  4256,  4144,	 4032, + 39233, 38181, 37157, 36157, 35181, 34229, 33297, 32389, 31501, 30629, + 29777, 28945, 28129, 27329, 26545, 25777, 25021, 24281, 23553, 22837, + 22137, 21445, 20769, 20101, 19445, 18801, 18165, 17541, 16925, 16321, + 15721, 15133, 14553, 13985, 13421, 12865, 12317, 11777, 11241, 10717, + 10197,	 9685,	9177,  8677,  8185,  7697,  7213,  6737,  6269,	 5801, +  5341,	 4889,	4437, 39930, 35534, 31186, 26886, 22630, 18418, 14254, + 10130,	 6046, 20055}; + +/* ------------------------------------------------------------------ */ +/* decLnOp -- effect natural logarithm				      */ +/*								      */ +/*   This computes C = ln(A)					      */ +/*								      */ +/*   res is C, the result.  C may be A				      */ +/*   rhs is A							      */ +/*   set is the context; note that rounding mode has no effect	      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Notable cases:						      */ +/*   A<0 -> Invalid						      */ +/*   A=0 -> -Infinity (Exact)					      */ +/*   A=+Infinity -> +Infinity (Exact)				      */ +/*   A=1 exactly -> 0 (Exact)					      */ +/*								      */ +/* Restrictions (as for Exp):					      */ +/*								      */ +/*   digits, emax, and -emin in the context must be less than	      */ +/*   DEC_MAX_MATH+11 (1000010), and the rhs must be within these      */ +/*   bounds or a zero.	This is an internal routine, so these	      */ +/*   restrictions are contractual and not enforced.		      */ +/*								      */ +/* A finite result is rounded using DEC_ROUND_HALF_EVEN; it will      */ +/* almost always be correctly rounded, but may be up to 1 ulp in      */ +/* error in rare cases.						      */ +/* ------------------------------------------------------------------ */ +/* The result is calculated using Newton's method, with each	      */ +/* iteration calculating a' = a + x * exp(-a) - 1.  See, for example, */ +/* Epperson 1989.						      */ +/*								      */ +/* The iteration ends when the adjustment x*exp(-a)-1 is tiny enough. */ +/* This has to be calculated at the sum of the precision of x and the */ +/* working precision.						      */ +/*								      */ +/* Implementation notes:					      */ +/*								      */ +/* 1. This is separated out as decLnOp so it can be called from	      */ +/*    other Mathematical functions (e.g., Log 10) with a wider range  */ +/*    than normal.  In particular, it can handle the slightly wider   */ +/*    (+9+2) range needed by a power function.			      */ +/*								      */ +/* 2. The speed of this function is about 10x slower than exp, as     */ +/*    it typically needs 4-6 iterations for short numbers, and the    */ +/*    extra precision needed adds a squaring effect, twice.	      */ +/*								      */ +/* 3. Fastpaths are included for ln(10) and ln(2), up to length 40,   */ +/*    as these are common requests.  ln(10) is used by log10(x).      */ +/*								      */ +/* 4. An iteration might be saved by widening the LNnn table, and     */ +/*    would certainly save at least one if it were made ten times     */ +/*    bigger, too (for truncated fractions 0.100 through 0.999).      */ +/*    However, for most practical evaluations, at least four or five  */ +/*    iterations will be neede -- so this would only speed up by      */ +/*    20-25% and that probably does not justify increasing the table  */ +/*    size.							      */ +/*								      */ +/* 5. The static buffers are larger than might be expected to allow   */ +/*    for calls from decNumberPower.				      */ +/* ------------------------------------------------------------------ */ +static decNumber *decLnOp(decNumber *res, const decNumber *rhs, +                          decContext *set, uInt *status) { +  uInt ignore=0;		   /* working status accumulator */ +  uInt needbytes;		   /* for space calculations */ +  Int residue;			   /* rounding residue */ +  Int r;			   /* rhs=f*10**r [see below] */ +  Int p;			   /* working precision */ +  Int pp;			   /* precision for iteration */ +  Int t;			   /* work */ + +  /* buffers for a (accumulator, typically precision+2) and b */ +  /* (adjustment calculator, same size) */ +  decNumber bufa[D2N(DECBUFFER+12)]; +  decNumber *allocbufa=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *a=bufa;		   /* accumulator/work */ +  decNumber bufb[D2N(DECBUFFER*2+2)]; +  decNumber *allocbufb=NULL;	   /* -> allocated bufa, iff allocated */ +  decNumber *b=bufb;		   /* adjustment/work */ + +  decNumber  numone;		   /* constant 1 */ +  decNumber  cmp;		   /* work */ +  decContext aset, bset;	   /* working contexts */ + +  #if DECCHECK +  Int iterations=0;		   /* for later sanity check */ +  if (decCheckOperands(res, DECUNUSED, rhs, set)) return res; +  #endif + +  do {					/* protect allocated storage */ +    if (SPECIALARG) {			/* handle infinities and NaNs */ +      if (decNumberIsInfinite(rhs)) {	/* an infinity */ +	if (decNumberIsNegative(rhs))	/* -Infinity -> error */ +	  *status|=DEC_Invalid_operation; +	 else decNumberCopy(res, rhs);	/* +Infinity -> self */ +	} +       else decNaNs(res, rhs, NULL, set, status); /* a NaN */ +      break;} + +    if (ISZERO(rhs)) {			/* +/- zeros -> -Infinity */ +      decNumberZero(res);		/* make clean */ +      res->bits=DECINF|DECNEG;		/* set - infinity */ +      break;}				/* [no status to set] */ + +    /* Non-zero negatives are bad... */ +    if (decNumberIsNegative(rhs)) {	/* -x -> error */ +      *status|=DEC_Invalid_operation; +      break;} + +    /* Here, rhs is positive, finite, and in range */ + +    /* lookaside fastpath code for ln(2) and ln(10) at common lengths */ +    if (rhs->exponent==0 && set->digits<=40) { +      #if DECDPUN==1 +      if (rhs->lsu[0]==0 && rhs->lsu[1]==1 && rhs->digits==2) { /* ln(10) */ +      #else +      if (rhs->lsu[0]==10 && rhs->digits==2) {			/* ln(10) */ +      #endif +	aset=*set; aset.round=DEC_ROUND_HALF_EVEN; +	#define LN10 "2.302585092994045684017991454684364207601" +	decNumberFromString(res, LN10, &aset); +	*status|=(DEC_Inexact | DEC_Rounded); /* is inexact */ +	break;} +      if (rhs->lsu[0]==2 && rhs->digits==1) { /* ln(2) */ +	aset=*set; aset.round=DEC_ROUND_HALF_EVEN; +	#define LN2 "0.6931471805599453094172321214581765680755" +	decNumberFromString(res, LN2, &aset); +	*status|=(DEC_Inexact | DEC_Rounded); +	break;} +      } /* integer and short */ + +    /* Determine the working precision.	 This is normally the */ +    /* requested precision + 2, with a minimum of 9.  However, if */ +    /* the rhs is 'over-precise' then allow for all its digits to */ +    /* potentially participate (consider an rhs where all the excess */ +    /* digits are 9s) so in this case use rhs->digits+2. */ +    p=MAXI(rhs->digits, MAXI(set->digits, 7))+2; + +    /* Allocate space for the accumulator and the high-precision */ +    /* adjustment calculator, if necessary.  The accumulator must */ +    /* be able to hold p digits, and the adjustment up to */ +    /* rhs->digits+p digits.  They are also made big enough for 16 */ +    /* digits so that they can be used for calculating the initial */ +    /* estimate. */ +    needbytes=sizeof(decNumber)+(D2U(MAXI(p,16))-1)*sizeof(Unit); +    if (needbytes>sizeof(bufa)) {     /* need malloc space */ +      allocbufa=(decNumber *)malloc(needbytes); +      if (allocbufa==NULL) {	      /* hopeless -- abandon */ +	*status|=DEC_Insufficient_storage; +	break;} +      a=allocbufa;		      /* use the allocated space */ +      } +    pp=p+rhs->digits; +    needbytes=sizeof(decNumber)+(D2U(MAXI(pp,16))-1)*sizeof(Unit); +    if (needbytes>sizeof(bufb)) {     /* need malloc space */ +      allocbufb=(decNumber *)malloc(needbytes); +      if (allocbufb==NULL) {	      /* hopeless -- abandon */ +	*status|=DEC_Insufficient_storage; +	break;} +      b=allocbufb;		      /* use the allocated space */ +      } + +    /* Prepare an initial estimate in acc. Calculate this by */ +    /* considering the coefficient of x to be a normalized fraction, */ +    /* f, with the decimal point at far left and multiplied by */ +    /* 10**r.  Then, rhs=f*10**r and 0.1<=f<1, and */ +    /*	 ln(x) = ln(f) + ln(10)*r */ +    /* Get the initial estimate for ln(f) from a small lookup */ +    /* table (see above) indexed by the first two digits of f, */ +    /* truncated. */ + +    decContextDefault(&aset, DEC_INIT_DECIMAL64); /* 16-digit extended */ +    r=rhs->exponent+rhs->digits;	/* 'normalised' exponent */ +    decNumberFromInt32(a, r);		/* a=r */ +    decNumberFromInt32(b, 2302585);	/* b=ln(10) (2.302585) */ +    b->exponent=-6;			/*  .. */ +    decMultiplyOp(a, a, b, &aset, &ignore);  /* a=a*b */ +    /* now get top two digits of rhs into b by simple truncate and */ +    /* force to integer */ +    residue=0;				/* (no residue) */ +    aset.digits=2; aset.round=DEC_ROUND_DOWN; +    decCopyFit(b, rhs, &aset, &residue, &ignore); /* copy & shorten */ +    b->exponent=0;			/* make integer */ +    t=decGetInt(b);			/* [cannot fail] */ +    if (t<10) t=X10(t);			/* adjust single-digit b */ +    t=LNnn[t-10];			/* look up ln(b) */ +    decNumberFromInt32(b, t>>2);	/* b=ln(b) coefficient */ +    b->exponent=-(t&3)-3;		/* set exponent */ +    b->bits=DECNEG;			/* ln(0.10)->ln(0.99) always -ve */ +    aset.digits=16; aset.round=DEC_ROUND_HALF_EVEN; /* restore */ +    decAddOp(a, a, b, &aset, 0, &ignore); /* acc=a+b */ +    /* the initial estimate is now in a, with up to 4 digits correct. */ +    /* When rhs is at or near Nmax the estimate will be low, so we */ +    /* will approach it from below, avoiding overflow when calling exp. */ + +    decNumberZero(&numone); *numone.lsu=1;   /* constant 1 for adjustment */ + +    /* accumulator bounds are as requested (could underflow, but */ +    /* cannot overflow) */ +    aset.emax=set->emax; +    aset.emin=set->emin; +    aset.clamp=0;			/* no concrete format */ +    /* set up a context to be used for the multiply and subtract */ +    bset=aset; +    bset.emax=DEC_MAX_MATH*2;		/* use double bounds for the */ +    bset.emin=-DEC_MAX_MATH*2;		/* adjustment calculation */ +					/* [see decExpOp call below] */ +    /* for each iteration double the number of digits to calculate, */ +    /* up to a maximum of p */ +    pp=9;				/* initial precision */ +    /* [initially 9 as then the sequence starts 7+2, 16+2, and */ +    /* 34+2, which is ideal for standard-sized numbers] */ +    aset.digits=pp;			/* working context */ +    bset.digits=pp+rhs->digits;		/* wider context */ +    for (;;) {				/* iterate */ +      #if DECCHECK +      iterations++; +      if (iterations>24) break;		/* consider 9 * 2**24 */ +      #endif +      /* calculate the adjustment (exp(-a)*x-1) into b.	 This is a */ +      /* catastrophic subtraction but it really is the difference */ +      /* from 1 that is of interest. */ +      /* Use the internal entry point to Exp as it allows the double */ +      /* range for calculating exp(-a) when a is the tiniest subnormal. */ +      a->bits^=DECNEG;			/* make -a */ +      decExpOp(b, a, &bset, &ignore);	/* b=exp(-a) */ +      a->bits^=DECNEG;			/* restore sign of a */ +      /* now multiply by rhs and subtract 1, at the wider precision */ +      decMultiplyOp(b, b, rhs, &bset, &ignore);	       /* b=b*rhs */ +      decAddOp(b, b, &numone, &bset, DECNEG, &ignore); /* b=b-1 */ + +      /* the iteration ends when the adjustment cannot affect the */ +      /* result by >=0.5 ulp (at the requested digits), which */ +      /* is when its value is smaller than the accumulator by */ +      /* set->digits+1 digits (or it is zero) -- this is a looser */ +      /* requirement than for Exp because all that happens to the */ +      /* accumulator after this is the final rounding (but note that */ +      /* there must also be full precision in a, or a=0). */ + +      if (decNumberIsZero(b) || +	  (a->digits+a->exponent)>=(b->digits+b->exponent+set->digits+1)) { +	if (a->digits==p) break; +	if (decNumberIsZero(a)) { +	  decCompareOp(&cmp, rhs, &numone, &aset, COMPARE, &ignore); /* rhs=1 ? */ +	  if (cmp.lsu[0]==0) a->exponent=0;	       /* yes, exact 0 */ +	   else *status|=(DEC_Inexact | DEC_Rounded);  /* no, inexact */ +	  break; +	  } +	/* force padding if adjustment has gone to 0 before full length */ +	if (decNumberIsZero(b)) b->exponent=a->exponent-p; +	} + +      /* not done yet ... */ +      decAddOp(a, a, b, &aset, 0, &ignore);  /* a=a+b for next estimate */ +      if (pp==p) continue;		     /* precision is at maximum */ +      /* lengthen the next calculation */ +      pp=pp*2;				     /* double precision */ +      if (pp>p) pp=p;			     /* clamp to maximum */ +      aset.digits=pp;			     /* working context */ +      bset.digits=pp+rhs->digits;	     /* wider context */ +      } /* Newton's iteration */ + +    #if DECCHECK +    /* just a sanity check; remove the test to show always */ +    if (iterations>24) +      printf("Ln iterations=%ld, status=%08lx, p=%ld, d=%ld\n", +	    iterations, *status, p, rhs->digits); +    #endif + +    /* Copy and round the result to res */ +    residue=1;				/* indicate dirt to right */ +    if (ISZERO(a)) residue=0;		/* .. unless underflowed to 0 */ +    aset.digits=set->digits;		/* [use default rounding] */ +    decCopyFit(res, a, &aset, &residue, status); /* copy & shorten */ +    decFinish(res, set, &residue, status);	 /* cleanup/set flags */ +    } while(0);				/* end protected */ + +  if (allocbufa!=NULL) free(allocbufa); /* drop any storage used */ +  if (allocbufb!=NULL) free(allocbufb); /* .. */ +  /* [status is handled by caller] */ +  return res; +  } /* decLnOp */ + +/* ------------------------------------------------------------------ */ +/* decQuantizeOp  -- force exponent to requested value		      */ +/*								      */ +/*   This computes C = op(A, B), where op adjusts the coefficient     */ +/*   of C (by rounding or shifting) such that the exponent (-scale)   */ +/*   of C has the value B or matches the exponent of B.		      */ +/*   The numerical value of C will equal A, except for the effects of */ +/*   any rounding that occurred.				      */ +/*								      */ +/*   res is C, the result.  C may be A or B			      */ +/*   lhs is A, the number to adjust				      */ +/*   rhs is B, the requested exponent				      */ +/*   set is the context						      */ +/*   quant is 1 for quantize or 0 for rescale			      */ +/*   status is the status accumulator (this can be called without     */ +/*	    risk of control loss)				      */ +/*								      */ +/* C must have space for set->digits digits.			      */ +/*								      */ +/* Unless there is an error or the result is infinite, the exponent   */ +/* after the operation is guaranteed to be that requested.	      */ +/* ------------------------------------------------------------------ */ +static decNumber * decQuantizeOp(decNumber *res, const decNumber *lhs, +				 const decNumber *rhs, decContext *set, +				 Flag quant, uInt *status) { +  #if DECSUBSET +  decNumber *alloclhs=NULL;	   /* non-NULL if rounded lhs allocated */ +  decNumber *allocrhs=NULL;	   /* .., rhs */ +  #endif +  const decNumber *inrhs=rhs;	   /* save original rhs */ +  Int	reqdigits=set->digits;	   /* requested DIGITS */ +  Int	reqexp;			   /* requested exponent [-scale] */ +  Int	residue=0;		   /* rounding residue */ +  Int	etiny=set->emin-(reqdigits-1); + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operands and set lostDigits status, as needed */ +      if (lhs->digits>reqdigits) { +	alloclhs=decRoundOperand(lhs, set, status); +	if (alloclhs==NULL) break; +	lhs=alloclhs; +	} +      if (rhs->digits>reqdigits) { /* [this only checks lostDigits] */ +	allocrhs=decRoundOperand(rhs, set, status); +	if (allocrhs==NULL) break; +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* Handle special values */ +    if (SPECIALARGS) { +      /* NaNs get usual processing */ +      if (SPECIALARGS & (DECSNAN | DECNAN)) +	decNaNs(res, lhs, rhs, set, status); +      /* one infinity but not both is bad */ +      else if ((lhs->bits ^ rhs->bits) & DECINF) +	*status|=DEC_Invalid_operation; +      /* both infinity: return lhs */ +      else decNumberCopy(res, lhs);	     /* [nop if in place] */ +      break; +      } + +    /* set requested exponent */ +    if (quant) reqexp=inrhs->exponent;	/* quantize -- match exponents */ +     else {				/* rescale -- use value of rhs */ +      /* Original rhs must be an integer that fits and is in range, */ +      /* which could be from -1999999997 to +999999999, thanks to */ +      /* subnormals */ +      reqexp=decGetInt(inrhs);		     /* [cannot fail] */ +      } + +    #if DECSUBSET +    if (!set->extended) etiny=set->emin;     /* no subnormals */ +    #endif + +    if (reqexp==BADINT			     /* bad (rescale only) or .. */ +     || reqexp==BIGODD || reqexp==BIGEVEN    /* very big (ditto) or .. */ +     || (reqexp<etiny)			     /* < lowest */ +     || (reqexp>set->emax)) {		     /* > emax */ +      *status|=DEC_Invalid_operation; +      break;} + +    /* the RHS has been processed, so it can be overwritten now if necessary */ +    if (ISZERO(lhs)) {			     /* zero coefficient unchanged */ +      decNumberCopy(res, lhs);		     /* [nop if in place] */ +      res->exponent=reqexp;		     /* .. just set exponent */ +      #if DECSUBSET +      if (!set->extended) res->bits=0;	     /* subset specification; no -0 */ +      #endif +      } +     else {				     /* non-zero lhs */ +      Int adjust=reqexp-lhs->exponent;	     /* digit adjustment needed */ +      /* if adjusted coefficient will definitely not fit, give up now */ +      if ((lhs->digits-adjust)>reqdigits) { +	*status|=DEC_Invalid_operation; +	break; +	} + +      if (adjust>0) {			     /* increasing exponent */ +	/* this will decrease the length of the coefficient by adjust */ +	/* digits, and must round as it does so */ +	decContext workset;		     /* work */ +	workset=*set;			     /* clone rounding, etc. */ +	workset.digits=lhs->digits-adjust;   /* set requested length */ +	/* [note that the latter can be <1, here] */ +	decCopyFit(res, lhs, &workset, &residue, status); /* fit to result */ +	decApplyRound(res, &workset, residue, status);	  /* .. and round */ +	residue=0;					  /* [used] */ +	/* If just rounded a 999s case, exponent will be off by one; */ +	/* adjust back (after checking space), if so. */ +	if (res->exponent>reqexp) { +	  /* re-check needed, e.g., for quantize(0.9999, 0.001) under */ +	  /* set->digits==3 */ +	  if (res->digits==reqdigits) {	     /* cannot shift by 1 */ +	    *status&=~(DEC_Inexact | DEC_Rounded); /* [clean these] */ +	    *status|=DEC_Invalid_operation; +	    break; +	    } +	  res->digits=decShiftToMost(res->lsu, res->digits, 1); /* shift */ +	  res->exponent--;		     /* (re)adjust the exponent. */ +	  } +	#if DECSUBSET +	if (ISZERO(res) && !set->extended) res->bits=0; /* subset; no -0 */ +	#endif +	} /* increase */ +       else /* adjust<=0 */ {		     /* decreasing or = exponent */ +	/* this will increase the length of the coefficient by -adjust */ +	/* digits, by adding zero or more trailing zeros; this is */ +	/* already checked for fit, above */ +	decNumberCopy(res, lhs);	     /* [it will fit] */ +	/* if padding needed (adjust<0), add it now... */ +	if (adjust<0) { +	  res->digits=decShiftToMost(res->lsu, res->digits, -adjust); +	  res->exponent+=adjust;	     /* adjust the exponent */ +	  } +	} /* decrease */ +      } /* non-zero */ + +    /* Check for overflow [do not use Finalize in this case, as an */ +    /* overflow here is a "don't fit" situation] */ +    if (res->exponent>set->emax-res->digits+1) {  /* too big */ +      *status|=DEC_Invalid_operation; +      break; +      } +     else { +      decFinalize(res, set, &residue, status);	  /* set subnormal flags */ +      *status&=~DEC_Underflow;		/* suppress Underflow [754r] */ +      } +    } while(0);				/* end protected */ + +  #if DECSUBSET +  if (allocrhs!=NULL) free(allocrhs);	/* drop any storage used */ +  if (alloclhs!=NULL) free(alloclhs);	/* .. */ +  #endif +  return res; +  } /* decQuantizeOp */ + +/* ------------------------------------------------------------------ */ +/* decCompareOp -- compare, min, or max two Numbers		      */ +/*								      */ +/*   This computes C = A ? B and carries out one of four operations:  */ +/*     COMPARE	  -- returns the signum (as a number) giving the      */ +/*		     result of a comparison unless one or both	      */ +/*		     operands is a NaN (in which case a NaN results)  */ +/*     COMPSIG	  -- as COMPARE except that a quiet NaN raises	      */ +/*		     Invalid operation.				      */ +/*     COMPMAX	  -- returns the larger of the operands, using the    */ +/*		     754r maxnum operation			      */ +/*     COMPMAXMAG -- ditto, comparing absolute values		      */ +/*     COMPMIN	  -- the 754r minnum operation			      */ +/*     COMPMINMAG -- ditto, comparing absolute values		      */ +/*     COMTOTAL	  -- returns the signum (as a number) giving the      */ +/*		     result of a comparison using 754r total ordering */ +/*								      */ +/*   res is C, the result.  C may be A and/or B (e.g., X=X?X)	      */ +/*   lhs is A							      */ +/*   rhs is B							      */ +/*   set is the context						      */ +/*   op	 is the operation flag					      */ +/*   status is the usual accumulator				      */ +/*								      */ +/* C must have space for one digit for COMPARE or set->digits for     */ +/* COMPMAX, COMPMIN, COMPMAXMAG, or COMPMINMAG.			      */ +/* ------------------------------------------------------------------ */ +/* The emphasis here is on speed for common cases, and avoiding	      */ +/* coefficient comparison if possible.				      */ +/* ------------------------------------------------------------------ */ +static decNumber *decCompareOp(decNumber *res, const decNumber *lhs, +                               const decNumber *rhs, decContext *set, +                               Flag op, uInt *status) { +  #if DECSUBSET +  decNumber *alloclhs=NULL;	   /* non-NULL if rounded lhs allocated */ +  decNumber *allocrhs=NULL;	   /* .., rhs */ +  #endif +  Int	result=0;		   /* default result value */ +  uByte merged;			   /* work */ + +  #if DECCHECK +  if (decCheckOperands(res, lhs, rhs, set)) return res; +  #endif + +  do {				   /* protect allocated storage */ +    #if DECSUBSET +    if (!set->extended) { +      /* reduce operands and set lostDigits status, as needed */ +      if (lhs->digits>set->digits) { +	alloclhs=decRoundOperand(lhs, set, status); +	if (alloclhs==NULL) {result=BADINT; break;} +	lhs=alloclhs; +	} +      if (rhs->digits>set->digits) { +	allocrhs=decRoundOperand(rhs, set, status); +	if (allocrhs==NULL) {result=BADINT; break;} +	rhs=allocrhs; +	} +      } +    #endif +    /* [following code does not require input rounding] */ + +    /* If total ordering then handle differing signs 'up front' */ +    if (op==COMPTOTAL) {		/* total ordering */ +      if (decNumberIsNegative(lhs) && !decNumberIsNegative(rhs)) { +	result=-1; +	break; +	} +      if (!decNumberIsNegative(lhs) && decNumberIsNegative(rhs)) { +	result=+1; +	break; +	} +      } + +    /* handle NaNs specially; let infinities drop through */ +    /* This assumes sNaN (even just one) leads to NaN. */ +    merged=(lhs->bits | rhs->bits) & (DECSNAN | DECNAN); +    if (merged) {			/* a NaN bit set */ +      if (op==COMPARE);			/* result will be NaN */ +       else if (op==COMPSIG)		/* treat qNaN as sNaN */ +	*status|=DEC_Invalid_operation | DEC_sNaN; +       else if (op==COMPTOTAL) {	/* total ordering, always finite */ +	/* signs are known to be the same; compute the ordering here */ +	/* as if the signs are both positive, then invert for negatives */ +	if (!decNumberIsNaN(lhs)) result=-1; +	 else if (!decNumberIsNaN(rhs)) result=+1; +	 /* here if both NaNs */ +	 else if (decNumberIsSNaN(lhs) && decNumberIsQNaN(rhs)) result=-1; +	 else if (decNumberIsQNaN(lhs) && decNumberIsSNaN(rhs)) result=+1; +	 else { /* both NaN or both sNaN */ +	  /* now it just depends on the payload */ +	  result=decUnitCompare(lhs->lsu, D2U(lhs->digits), +				rhs->lsu, D2U(rhs->digits), 0); +	  /* [Error not possible, as these are 'aligned'] */ +	  } /* both same NaNs */ +	if (decNumberIsNegative(lhs)) result=-result; +	break; +	} /* total order */ + +       else if (merged & DECSNAN);	     /* sNaN -> qNaN */ +       else { /* here if MIN or MAX and one or two quiet NaNs */ +	/* min or max -- 754r rules ignore single NaN */ +	if (!decNumberIsNaN(lhs) || !decNumberIsNaN(rhs)) { +	  /* just one NaN; force choice to be the non-NaN operand */ +	  op=COMPMAX; +	  if (lhs->bits & DECNAN) result=-1; /* pick rhs */ +			     else result=+1; /* pick lhs */ +	  break; +	  } +	} /* max or min */ +      op=COMPNAN;			     /* use special path */ +      decNaNs(res, lhs, rhs, set, status);   /* propagate NaN */ +      break; +      } +    /* have numbers */ +    if (op==COMPMAXMAG || op==COMPMINMAG) result=decCompare(lhs, rhs, 1); +     else result=decCompare(lhs, rhs, 0);    /* sign matters */ +    } while(0);				     /* end protected */ + +  if (result==BADINT) *status|=DEC_Insufficient_storage; /* rare */ +   else { +    if (op==COMPARE || op==COMPSIG ||op==COMPTOTAL) { /* returning signum */ +      if (op==COMPTOTAL && result==0) { +	/* operands are numerically equal or same NaN (and same sign, */ +	/* tested first); if identical, leave result 0 */ +	if (lhs->exponent!=rhs->exponent) { +	  if (lhs->exponent<rhs->exponent) result=-1; +	   else result=+1; +	  if (decNumberIsNegative(lhs)) result=-result; +	  } /* lexp!=rexp */ +	} /* total-order by exponent */ +      decNumberZero(res);		/* [always a valid result] */ +      if (result!=0) {			/* must be -1 or +1 */ +	*res->lsu=1; +	if (result<0) res->bits=DECNEG; +	} +      } +     else if (op==COMPNAN);		/* special, drop through */ +     else {				/* MAX or MIN, non-NaN result */ +      Int residue=0;			/* rounding accumulator */ +      /* choose the operand for the result */ +      const decNumber *choice; +      if (result==0) { /* operands are numerically equal */ +	/* choose according to sign then exponent (see 754r) */ +	uByte slhs=(lhs->bits & DECNEG); +	uByte srhs=(rhs->bits & DECNEG); +	#if DECSUBSET +	if (!set->extended) {		/* subset: force left-hand */ +	  op=COMPMAX; +	  result=+1; +	  } +	else +	#endif +	if (slhs!=srhs) {	   /* signs differ */ +	  if (slhs) result=-1;	   /* rhs is max */ +	       else result=+1;	   /* lhs is max */ +	  } +	 else if (slhs && srhs) {  /* both negative */ +	  if (lhs->exponent<rhs->exponent) result=+1; +				      else result=-1; +	  /* [if equal, use lhs, technically identical] */ +	  } +	 else {			   /* both positive */ +	  if (lhs->exponent>rhs->exponent) result=+1; +				      else result=-1; +	  /* [ditto] */ +	  } +	} /* numerically equal */ +      /* here result will be non-0; reverse if looking for MIN */ +      if (op==COMPMIN || op==COMPMINMAG) result=-result; +      choice=(result>0 ? lhs : rhs);	/* choose */ +      /* copy chosen to result, rounding if need be */ +      decCopyFit(res, choice, set, &residue, status); +      decFinish(res, set, &residue, status); +      } +    } +  #if DECSUBSET +  if (allocrhs!=NULL) free(allocrhs);	/* free any storage used */ +  if (alloclhs!=NULL) free(alloclhs);	/* .. */ +  #endif +  return res; +  } /* decCompareOp */ + +/* ------------------------------------------------------------------ */ +/* decCompare -- compare two decNumbers by numerical value	      */ +/*								      */ +/*  This routine compares A ? B without altering them.		      */ +/*								      */ +/*  Arg1 is A, a decNumber which is not a NaN			      */ +/*  Arg2 is B, a decNumber which is not a NaN			      */ +/*  Arg3 is 1 for a sign-independent compare, 0 otherwise	      */ +/*								      */ +/*  returns -1, 0, or 1 for A<B, A==B, or A>B, or BADINT if failure   */ +/*  (the only possible failure is an allocation error)		      */ +/* ------------------------------------------------------------------ */ +static Int decCompare(const decNumber *lhs, const decNumber *rhs, +		      Flag abs) { +  Int	result;			   /* result value */ +  Int	sigr;			   /* rhs signum */ +  Int	compare;		   /* work */ + +  result=1;				     /* assume signum(lhs) */ +  if (ISZERO(lhs)) result=0; +  if (abs) { +    if (ISZERO(rhs)) return result;	     /* LHS wins or both 0 */ +    /* RHS is non-zero */ +    if (result==0) return -1;		     /* LHS is 0; RHS wins */ +    /* [here, both non-zero, result=1] */ +    } +   else {				     /* signs matter */ +    if (result && decNumberIsNegative(lhs)) result=-1; +    sigr=1;				     /* compute signum(rhs) */ +    if (ISZERO(rhs)) sigr=0; +     else if (decNumberIsNegative(rhs)) sigr=-1; +    if (result > sigr) return +1;	     /* L > R, return 1 */ +    if (result < sigr) return -1;	     /* L < R, return -1 */ +    if (result==0) return 0;		       /* both 0 */ +    } + +  /* signums are the same; both are non-zero */ +  if ((lhs->bits | rhs->bits) & DECINF) {    /* one or more infinities */ +    if (decNumberIsInfinite(rhs)) { +      if (decNumberIsInfinite(lhs)) result=0;/* both infinite */ +       else result=-result;		     /* only rhs infinite */ +      } +    return result; +    } +  /* must compare the coefficients, allowing for exponents */ +  if (lhs->exponent>rhs->exponent) {	     /* LHS exponent larger */ +    /* swap sides, and sign */ +    const decNumber *temp=lhs; +    lhs=rhs; +    rhs=temp; +    result=-result; +    } +  compare=decUnitCompare(lhs->lsu, D2U(lhs->digits), +			 rhs->lsu, D2U(rhs->digits), +			 rhs->exponent-lhs->exponent); +  if (compare!=BADINT) compare*=result;	     /* comparison succeeded */ +  return compare; +  } /* decCompare */ + +/* ------------------------------------------------------------------ */ +/* decUnitCompare -- compare two >=0 integers in Unit arrays	      */ +/*								      */ +/*  This routine compares A ? B*10**E where A and B are unit arrays   */ +/*  A is a plain integer					      */ +/*  B has an exponent of E (which must be non-negative)		      */ +/*								      */ +/*  Arg1 is A first Unit (lsu)					      */ +/*  Arg2 is A length in Units					      */ +/*  Arg3 is B first Unit (lsu)					      */ +/*  Arg4 is B length in Units					      */ +/*  Arg5 is E (0 if the units are aligned)			      */ +/*								      */ +/*  returns -1, 0, or 1 for A<B, A==B, or A>B, or BADINT if failure   */ +/*  (the only possible failure is an allocation error, which can      */ +/*  only occur if E!=0)						      */ +/* ------------------------------------------------------------------ */ +static Int decUnitCompare(const Unit *a, Int alength, +			  const Unit *b, Int blength, Int exp) { +  Unit	*acc;			   /* accumulator for result */ +  Unit	accbuff[SD2U(DECBUFFER*2+1)]; /* local buffer */ +  Unit	*allocacc=NULL;		   /* -> allocated acc buffer, iff allocated */ +  Int	accunits, need;		   /* units in use or needed for acc */ +  const Unit *l, *r, *u;	   /* work */ +  Int	expunits, exprem, result;  /* .. */ + +  if (exp==0) {			   /* aligned; fastpath */ +    if (alength>blength) return 1; +    if (alength<blength) return -1; +    /* same number of units in both -- need unit-by-unit compare */ +    l=a+alength-1; +    r=b+alength-1; +    for (;l>=a; l--, r--) { +      if (*l>*r) return 1; +      if (*l<*r) return -1; +      } +    return 0;			   /* all units match */ +    } /* aligned */ + +  /* Unaligned.	 If one is >1 unit longer than the other, padded */ +  /* approximately, then can return easily */ +  if (alength>blength+(Int)D2U(exp)) return 1; +  if (alength+1<blength+(Int)D2U(exp)) return -1; + +  /* Need to do a real subtract.  For this, a result buffer is needed */ +  /* even though only the sign is of interest.	Its length needs */ +  /* to be the larger of alength and padded blength, +2 */ +  need=blength+D2U(exp);		/* maximum real length of B */ +  if (need<alength) need=alength; +  need+=2; +  acc=accbuff;				/* assume use local buffer */ +  if (need*sizeof(Unit)>sizeof(accbuff)) { +    allocacc=(Unit *)malloc(need*sizeof(Unit)); +    if (allocacc==NULL) return BADINT;	/* hopeless -- abandon */ +    acc=allocacc; +    } +  /* Calculate units and remainder from exponent. */ +  expunits=exp/DECDPUN; +  exprem=exp%DECDPUN; +  /* subtract [A+B*(-m)] */ +  accunits=decUnitAddSub(a, alength, b, blength, expunits, acc, +			 -(Int)powers[exprem]); +  /* [UnitAddSub result may have leading zeros, even on zero] */ +  if (accunits<0) result=-1;		/* negative result */ +   else {				/* non-negative result */ +    /* check units of the result before freeing any storage */ +    for (u=acc; u<acc+accunits-1 && *u==0;) u++; +    result=(*u==0 ? 0 : +1); +    } +  /* clean up and return the result */ +  if (allocacc!=NULL) free(allocacc);	/* drop any storage used */ +  return result; +  } /* decUnitCompare */ + +/* ------------------------------------------------------------------ */ +/* decUnitAddSub -- add or subtract two >=0 integers in Unit arrays   */ +/*								      */ +/*  This routine performs the calculation:			      */ +/*								      */ +/*  C=A+(B*M)							      */ +/*								      */ +/*  Where M is in the range -DECDPUNMAX through +DECDPUNMAX.	      */ +/*								      */ +/*  A may be shorter or longer than B.				      */ +/*								      */ +/*  Leading zeros are not removed after a calculation.	The result is */ +/*  either the same length as the longer of A and B (adding any	      */ +/*  shift), or one Unit longer than that (if a Unit carry occurred).  */ +/*								      */ +/*  A and B content are not altered unless C is also A or B.	      */ +/*  C may be the same array as A or B, but only if no zero padding is */ +/*  requested (that is, C may be B only if bshift==0).		      */ +/*  C is filled from the lsu; only those units necessary to complete  */ +/*  the calculation are referenced.				      */ +/*								      */ +/*  Arg1 is A first Unit (lsu)					      */ +/*  Arg2 is A length in Units					      */ +/*  Arg3 is B first Unit (lsu)					      */ +/*  Arg4 is B length in Units					      */ +/*  Arg5 is B shift in Units  (>=0; pads with 0 units if positive)    */ +/*  Arg6 is C first Unit (lsu)					      */ +/*  Arg7 is M, the multiplier					      */ +/*								      */ +/*  returns the count of Units written to C, which will be non-zero   */ +/*  and negated if the result is negative.  That is, the sign of the  */ +/*  returned Int is the sign of the result (positive for zero) and    */ +/*  the absolute value of the Int is the count of Units.	      */ +/*								      */ +/*  It is the caller's responsibility to make sure that C size is     */ +/*  safe, allowing space if necessary for a one-Unit carry.	      */ +/*								      */ +/*  This routine is severely performance-critical; *any* change here  */ +/*  must be measured (timed) to assure no performance degradation.    */ +/*  In particular, trickery here tends to be counter-productive, as   */ +/*  increased complexity of code hurts register optimizations on      */ +/*  register-poor architectures.  Avoiding divisions is nearly	      */ +/*  always a Good Idea, however.				      */ +/*								      */ +/* Special thanks to Rick McGuire (IBM Cambridge, MA) and Dave Clark  */ +/* (IBM Warwick, UK) for some of the ideas used in this routine.      */ +/* ------------------------------------------------------------------ */ +static Int decUnitAddSub(const Unit *a, Int alength, +			 const Unit *b, Int blength, Int bshift, +			 Unit *c, Int m) { +  const Unit *alsu=a;		   /* A lsu [need to remember it] */ +  Unit *clsu=c;			   /* C ditto */ +  Unit *minC;			   /* low water mark for C */ +  Unit *maxC;			   /* high water mark for C */ +  eInt carry=0;			   /* carry integer (could be Long) */ +  Int  add;			   /* work */ +  #if DECDPUN<=4		   /* myriadal, millenary, etc. */ +  Int  est;			   /* estimated quotient */ +  #endif + +  #if DECTRACE +  if (alength<1 || blength<1) +    printf("decUnitAddSub: alen blen m %ld %ld [%ld]\n", alength, blength, m); +  #endif + +  maxC=c+alength;		   /* A is usually the longer */ +  minC=c+blength;		   /* .. and B the shorter */ +  if (bshift!=0) {		   /* B is shifted; low As copy across */ +    minC+=bshift; +    /* if in place [common], skip copy unless there's a gap [rare] */ +    if (a==c && bshift<=alength) { +      c+=bshift; +      a+=bshift; +      } +     else for (; c<clsu+bshift; a++, c++) {  /* copy needed */ +      if (a<alsu+alength) *c=*a; +       else *c=0; +      } +    } +  if (minC>maxC) { /* swap */ +    Unit *hold=minC; +    minC=maxC; +    maxC=hold; +    } + +  /* For speed, do the addition as two loops; the first where both A */ +  /* and B contribute, and the second (if necessary) where only one or */ +  /* other of the numbers contribute. */ +  /* Carry handling is the same (i.e., duplicated) in each case. */ +  for (; c<minC; c++) { +    carry+=*a; +    a++; +    carry+=((eInt)*b)*m;		/* [special-casing m=1/-1 */ +    b++;				/* here is not a win] */ +    /* here carry is new Unit of digits; it could be +ve or -ve */ +    if ((ueInt)carry<=DECDPUNMAX) {	/* fastpath 0-DECDPUNMAX */ +      *c=(Unit)carry; +      carry=0; +      continue; +      } +    #if DECDPUN==4			     /* use divide-by-multiply */ +      if (carry>=0) { +	est=(((ueInt)carry>>11)*53687)>>18; +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* likely quotient [89%] */ +	if (*c<DECDPUNMAX+1) continue;	     /* estimate was correct */ +	carry++; +	*c-=DECDPUNMAX+1; +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=(((ueInt)carry>>11)*53687)>>18; +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +      if (*c<DECDPUNMAX+1) continue;	     /* was OK */ +      carry++; +      *c-=DECDPUNMAX+1; +    #elif DECDPUN==3 +      if (carry>=0) { +	est=(((ueInt)carry>>3)*16777)>>21; +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* likely quotient [99%] */ +	if (*c<DECDPUNMAX+1) continue;	     /* estimate was correct */ +	carry++; +	*c-=DECDPUNMAX+1; +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=(((ueInt)carry>>3)*16777)>>21; +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +      if (*c<DECDPUNMAX+1) continue;	     /* was OK */ +      carry++; +      *c-=DECDPUNMAX+1; +    #elif DECDPUN<=2 +      /* Can use QUOT10 as carry <= 4 digits */ +      if (carry>=0) { +	est=QUOT10(carry, DECDPUN); +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* quotient */ +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=QUOT10(carry, DECDPUN); +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +    #else +      /* remainder operator is undefined if negative, so must test */ +      if ((ueInt)carry<(DECDPUNMAX+1)*2) {   /* fastpath carry +1 */ +	*c=(Unit)(carry-(DECDPUNMAX+1));     /* [helps additions] */ +	carry=1; +	continue; +	} +      if (carry>=0) { +	*c=(Unit)(carry%(DECDPUNMAX+1)); +	carry=carry/(DECDPUNMAX+1); +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      *c=(Unit)(carry%(DECDPUNMAX+1)); +      carry=carry/(DECDPUNMAX+1)-(DECDPUNMAX+1); +    #endif +    } /* c */ + +  /* now may have one or other to complete */ +  /* [pretest to avoid loop setup/shutdown] */ +  if (c<maxC) for (; c<maxC; c++) { +    if (a<alsu+alength) {		/* still in A */ +      carry+=*a; +      a++; +      } +     else {				/* inside B */ +      carry+=((eInt)*b)*m; +      b++; +      } +    /* here carry is new Unit of digits; it could be +ve or -ve and */ +    /* magnitude up to DECDPUNMAX squared */ +    if ((ueInt)carry<=DECDPUNMAX) {	/* fastpath 0-DECDPUNMAX */ +      *c=(Unit)carry; +      carry=0; +      continue; +      } +    /* result for this unit is negative or >DECDPUNMAX */ +    #if DECDPUN==4			     /* use divide-by-multiply */ +      if (carry>=0) { +	est=(((ueInt)carry>>11)*53687)>>18; +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* likely quotient [79.7%] */ +	if (*c<DECDPUNMAX+1) continue;	     /* estimate was correct */ +	carry++; +	*c-=DECDPUNMAX+1; +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=(((ueInt)carry>>11)*53687)>>18; +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +      if (*c<DECDPUNMAX+1) continue;	     /* was OK */ +      carry++; +      *c-=DECDPUNMAX+1; +    #elif DECDPUN==3 +      if (carry>=0) { +	est=(((ueInt)carry>>3)*16777)>>21; +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* likely quotient [99%] */ +	if (*c<DECDPUNMAX+1) continue;	     /* estimate was correct */ +	carry++; +	*c-=DECDPUNMAX+1; +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=(((ueInt)carry>>3)*16777)>>21; +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +      if (*c<DECDPUNMAX+1) continue;	     /* was OK */ +      carry++; +      *c-=DECDPUNMAX+1; +    #elif DECDPUN<=2 +      if (carry>=0) { +	est=QUOT10(carry, DECDPUN); +	*c=(Unit)(carry-est*(DECDPUNMAX+1)); /* remainder */ +	carry=est;			     /* quotient */ +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      est=QUOT10(carry, DECDPUN); +      *c=(Unit)(carry-est*(DECDPUNMAX+1)); +      carry=est-(DECDPUNMAX+1);		     /* correctly negative */ +    #else +      if ((ueInt)carry<(DECDPUNMAX+1)*2){    /* fastpath carry 1 */ +	*c=(Unit)(carry-(DECDPUNMAX+1)); +	carry=1; +	continue; +	} +      /* remainder operator is undefined if negative, so must test */ +      if (carry>=0) { +	*c=(Unit)(carry%(DECDPUNMAX+1)); +	carry=carry/(DECDPUNMAX+1); +	continue; +	} +      /* negative case */ +      carry=carry+(eInt)(DECDPUNMAX+1)*(DECDPUNMAX+1); /* make positive */ +      *c=(Unit)(carry%(DECDPUNMAX+1)); +      carry=carry/(DECDPUNMAX+1)-(DECDPUNMAX+1); +    #endif +    } /* c */ + +  /* OK, all A and B processed; might still have carry or borrow */ +  /* return number of Units in the result, negated if a borrow */ +  if (carry==0) return c-clsu;	   /* no carry, so no more to do */ +  if (carry>0) {		   /* positive carry */ +    *c=(Unit)carry;		   /* place as new unit */ +    c++;			   /* .. */ +    return c-clsu; +    } +  /* -ve carry: it's a borrow; complement needed */ +  add=1;			   /* temporary carry... */ +  for (c=clsu; c<maxC; c++) { +    add=DECDPUNMAX+add-*c; +    if (add<=DECDPUNMAX) { +      *c=(Unit)add; +      add=0; +      } +     else { +      *c=0; +      add=1; +      } +    } +  /* add an extra unit iff it would be non-zero */ +  #if DECTRACE +    printf("UAS borrow: add %ld, carry %ld\n", add, carry); +  #endif +  if ((add-carry-1)!=0) { +    *c=(Unit)(add-carry-1); +    c++;		      /* interesting, include it */ +    } +  return clsu-c;	      /* -ve result indicates borrowed */ +  } /* decUnitAddSub */ + +/* ------------------------------------------------------------------ */ +/* decTrim -- trim trailing zeros or normalize			      */ +/*								      */ +/*   dn is the number to trim or normalize			      */ +/*   set is the context to use to check for clamp		      */ +/*   all is 1 to remove all trailing zeros, 0 for just fraction ones  */ +/*   dropped returns the number of discarded trailing zeros	      */ +/*   returns dn							      */ +/*								      */ +/* If clamp is set in the context then the number of zeros trimmed    */ +/* may be limited if the exponent is high.			      */ +/* All fields are updated as required.	This is a utility operation,  */ +/* so special values are unchanged and no error is possible.	      */ +/* ------------------------------------------------------------------ */ +static decNumber * decTrim(decNumber *dn, decContext *set, Flag all, +			   Int *dropped) { +  Int	d, exp;			   /* work */ +  uInt	cut;			   /* .. */ +  Unit	*up;			   /* -> current Unit */ + +  #if DECCHECK +  if (decCheckOperands(dn, DECUNUSED, DECUNUSED, DECUNCONT)) return dn; +  #endif + +  *dropped=0;				/* assume no zeros dropped */ +  if ((dn->bits & DECSPECIAL)		/* fast exit if special .. */ +    || (*dn->lsu & 0x01)) return dn;	/* .. or odd */ +  if (ISZERO(dn)) {			/* .. or 0 */ +    dn->exponent=0;			/* (sign is preserved) */ +    return dn; +    } + +  /* have a finite number which is even */ +  exp=dn->exponent; +  cut=1;			   /* digit (1-DECDPUN) in Unit */ +  up=dn->lsu;			   /* -> current Unit */ +  for (d=0; d<dn->digits-1; d++) { /* [don't strip the final digit] */ +    /* slice by powers */ +    #if DECDPUN<=4 +      uInt quot=QUOT10(*up, cut); +      if ((*up-quot*powers[cut])!=0) break;  /* found non-0 digit */ +    #else +      if (*up%powers[cut]!=0) break;	     /* found non-0 digit */ +    #endif +    /* have a trailing 0 */ +    if (!all) {			   /* trimming */ +      /* [if exp>0 then all trailing 0s are significant for trim] */ +      if (exp<=0) {		   /* if digit might be significant */ +	if (exp==0) break;	   /* then quit */ +	exp++;			   /* next digit might be significant */ +	} +      } +    cut++;			   /* next power */ +    if (cut>DECDPUN) {		   /* need new Unit */ +      up++; +      cut=1; +      } +    } /* d */ +  if (d==0) return dn;		   /* none to drop */ + +  /* may need to limit drop if clamping */ +  if (set->clamp) { +    Int maxd=set->emax-set->digits+1-dn->exponent; +    if (maxd<=0) return dn;	   /* nothing possible */ +    if (d>maxd) d=maxd; +    } + +  /* effect the drop */ +  decShiftToLeast(dn->lsu, D2U(dn->digits), d); +  dn->exponent+=d;		   /* maintain numerical value */ +  dn->digits-=d;		   /* new length */ +  *dropped=d;			   /* report the count */ +  return dn; +  } /* decTrim */ + +/* ------------------------------------------------------------------ */ +/* decReverse -- reverse a Unit array in place			      */ +/*								      */ +/*   ulo    is the start of the array				      */ +/*   uhi    is the end of the array (highest Unit to include)	      */ +/*								      */ +/* The units ulo through uhi are reversed in place (if the number     */ +/* of units is odd, the middle one is untouched).  Note that the      */ +/* digit(s) in each unit are unaffected.			      */ +/* ------------------------------------------------------------------ */ +static void decReverse(Unit *ulo, Unit *uhi) { +  Unit temp; +  for (; ulo<uhi; ulo++, uhi--) { +    temp=*ulo; +    *ulo=*uhi; +    *uhi=temp; +    } +  return; +  } /* decReverse */ + +/* ------------------------------------------------------------------ */ +/* decShiftToMost -- shift digits in array towards most significant   */ +/*								      */ +/*   uar    is the array					      */ +/*   digits is the count of digits in use in the array		      */ +/*   shift  is the number of zeros to pad with (least significant);   */ +/*     it must be zero or positive				      */ +/*								      */ +/*   returns the new length of the integer in the array, in digits    */ +/*								      */ +/* No overflow is permitted (that is, the uar array must be known to  */ +/* be large enough to hold the result, after shifting).		      */ +/* ------------------------------------------------------------------ */ +static Int decShiftToMost(Unit *uar, Int digits, Int shift) { +  Unit	*target, *source, *first;  /* work */ +  Int	cut;			   /* odd 0's to add */ +  uInt	next;			   /* work */ + +  if (shift==0) return digits;	   /* [fastpath] nothing to do */ +  if ((digits+shift)<=DECDPUN) {   /* [fastpath] single-unit case */ +    *uar=(Unit)(*uar*powers[shift]); +    return digits+shift; +    } + +  next=0;			   /* all paths */ +  source=uar+D2U(digits)-1;	   /* where msu comes from */ +  target=source+D2U(shift);	   /* where upper part of first cut goes */ +  cut=DECDPUN-MSUDIGITS(shift);	   /* where to slice */ +  if (cut==0) {			   /* unit-boundary case */ +    for (; source>=uar; source--, target--) *target=*source; +    } +   else { +    first=uar+D2U(digits+shift)-1; /* where msu of source will end up */ +    for (; source>=uar; source--, target--) { +      /* split the source Unit and accumulate remainder for next */ +      #if DECDPUN<=4 +	uInt quot=QUOT10(*source, cut); +	uInt rem=*source-quot*powers[cut]; +	next+=quot; +      #else +	uInt rem=*source%powers[cut]; +	next+=*source/powers[cut]; +      #endif +      if (target<=first) *target=(Unit)next;   /* write to target iff valid */ +      next=rem*powers[DECDPUN-cut];	       /* save remainder for next Unit */ +      } +    } /* shift-move */ + +  /* propagate any partial unit to one below and clear the rest */ +  for (; target>=uar; target--) { +    *target=(Unit)next; +    next=0; +    } +  return digits+shift; +  } /* decShiftToMost */ + +/* ------------------------------------------------------------------ */ +/* decShiftToLeast -- shift digits in array towards least significant */ +/*								      */ +/*   uar   is the array						      */ +/*   units is length of the array, in units			      */ +/*   shift is the number of digits to remove from the lsu end; it     */ +/*     must be zero or positive and <= than units*DECDPUN.	      */ +/*								      */ +/*   returns the new length of the integer in the array, in units     */ +/*								      */ +/* Removed digits are discarded (lost).	 Units not required to hold   */ +/* the final result are unchanged.				      */ +/* ------------------------------------------------------------------ */ +static Int decShiftToLeast(Unit *uar, Int units, Int shift) { +  Unit	*target, *up;		   /* work */ +  Int	cut, count;		   /* work */ +  Int	quot, rem;		   /* for division */ + +  if (shift==0) return units;	   /* [fastpath] nothing to do */ +  if (shift==units*DECDPUN) {	   /* [fastpath] little to do */ +    *uar=0;			   /* all digits cleared gives zero */ +    return 1;			   /* leaves just the one */ +    } + +  target=uar;			   /* both paths */ +  cut=MSUDIGITS(shift); +  if (cut==DECDPUN) {		   /* unit-boundary case; easy */ +    up=uar+D2U(shift); +    for (; up<uar+units; target++, up++) *target=*up; +    return target-uar; +    } + +  /* messier */ +  up=uar+D2U(shift-cut);	   /* source; correct to whole Units */ +  count=units*DECDPUN-shift;	   /* the maximum new length */ +  #if DECDPUN<=4 +    quot=QUOT10(*up, cut); +  #else +    quot=*up/powers[cut]; +  #endif +  for (; ; target++) { +    *target=(Unit)quot; +    count-=(DECDPUN-cut); +    if (count<=0) break; +    up++; +    quot=*up; +    #if DECDPUN<=4 +      quot=QUOT10(quot, cut); +      rem=*up-quot*powers[cut]; +    #else +      rem=quot%powers[cut]; +      quot=quot/powers[cut]; +    #endif +    *target=(Unit)(*target+rem*powers[DECDPUN-cut]); +    count-=cut; +    if (count<=0) break; +    } +  return target-uar+1; +  } /* decShiftToLeast */ + +#if DECSUBSET +/* ------------------------------------------------------------------ */ +/* decRoundOperand -- round an operand	[used for subset only]	      */ +/*								      */ +/*   dn is the number to round (dn->digits is > set->digits)	      */ +/*   set is the relevant context				      */ +/*   status is the status accumulator				      */ +/*								      */ +/*   returns an allocated decNumber with the rounded result.	      */ +/*								      */ +/* lostDigits and other status may be set by this.		      */ +/*								      */ +/* Since the input is an operand, it must not be modified.	      */ +/* Instead, return an allocated decNumber, rounded as required.	      */ +/* It is the caller's responsibility to free the allocated storage.   */ +/*								      */ +/* If no storage is available then the result cannot be used, so NULL */ +/* is returned.							      */ +/* ------------------------------------------------------------------ */ +static decNumber *decRoundOperand(const decNumber *dn, decContext *set, +				  uInt *status) { +  decNumber *res;			/* result structure */ +  uInt newstatus=0;			/* status from round */ +  Int  residue=0;			/* rounding accumulator */ + +  /* Allocate storage for the returned decNumber, big enough for the */ +  /* length specified by the context */ +  res=(decNumber *)malloc(sizeof(decNumber) +			  +(D2U(set->digits)-1)*sizeof(Unit)); +  if (res==NULL) { +    *status|=DEC_Insufficient_storage; +    return NULL; +    } +  decCopyFit(res, dn, set, &residue, &newstatus); +  decApplyRound(res, set, residue, &newstatus); + +  /* If that set Inexact then "lost digits" is raised... */ +  if (newstatus & DEC_Inexact) newstatus|=DEC_Lost_digits; +  *status|=newstatus; +  return res; +  } /* decRoundOperand */ +#endif + +/* ------------------------------------------------------------------ */ +/* decCopyFit -- copy a number, truncating the coefficient if needed  */ +/*								      */ +/*   dest is the target decNumber				      */ +/*   src  is the source decNumber				      */ +/*   set is the context [used for length (digits) and rounding mode]  */ +/*   residue is the residue accumulator				      */ +/*   status contains the current status to be updated		      */ +/*								      */ +/* (dest==src is allowed and will be a no-op if fits)		      */ +/* All fields are updated as required.				      */ +/* ------------------------------------------------------------------ */ +static void decCopyFit(decNumber *dest, const decNumber *src, +		       decContext *set, Int *residue, uInt *status) { +  dest->bits=src->bits; +  dest->exponent=src->exponent; +  decSetCoeff(dest, set, src->lsu, src->digits, residue, status); +  } /* decCopyFit */ + +/* ------------------------------------------------------------------ */ +/* decSetCoeff -- set the coefficient of a number		      */ +/*								      */ +/*   dn	   is the number whose coefficient array is to be set.	      */ +/*	   It must have space for set->digits digits		      */ +/*   set   is the context [for size]				      */ +/*   lsu   -> lsu of the source coefficient [may be dn->lsu]	      */ +/*   len   is digits in the source coefficient [may be dn->digits]    */ +/*   residue is the residue accumulator.  This has values as in	      */ +/*	   decApplyRound, and will be unchanged unless the	      */ +/*	   target size is less than len.  In this case, the	      */ +/*	   coefficient is truncated and the residue is updated to     */ +/*	   reflect the previous residue and the dropped digits.	      */ +/*   status is the status accumulator, as usual			      */ +/*								      */ +/* The coefficient may already be in the number, or it can be an      */ +/* external intermediate array.	 If it is in the number, lsu must ==  */ +/* dn->lsu and len must == dn->digits.				      */ +/*								      */ +/* Note that the coefficient length (len) may be < set->digits, and   */ +/* in this case this merely copies the coefficient (or is a no-op     */ +/* if dn->lsu==lsu).						      */ +/*								      */ +/* Note also that (only internally, from decQuantizeOp and	      */ +/* decSetSubnormal) the value of set->digits may be less than one,    */ +/* indicating a round to left.	This routine handles that case	      */ +/* correctly; caller ensures space.				      */ +/*								      */ +/* dn->digits, dn->lsu (and as required), and dn->exponent are	      */ +/* updated as necessary.   dn->bits (sign) is unchanged.	      */ +/*								      */ +/* DEC_Rounded status is set if any digits are discarded.	      */ +/* DEC_Inexact status is set if any non-zero digits are discarded, or */ +/*			 incoming residue was non-0 (implies rounded) */ +/* ------------------------------------------------------------------ */ +/* mapping array: maps 0-9 to canonical residues, so that a residue */ +/* can be adjusted in the range [-1, +1] and achieve correct rounding */ +/*			       0  1  2	3  4  5	 6  7  8  9 */ +static const uByte resmap[10]={0, 3, 3, 3, 3, 5, 7, 7, 7, 7}; +static void decSetCoeff(decNumber *dn, decContext *set, const Unit *lsu, +			Int len, Int *residue, uInt *status) { +  Int	discard;	      /* number of digits to discard */ +  uInt	cut;		      /* cut point in Unit */ +  const Unit *up;	      /* work */ +  Unit	*target;	      /* .. */ +  Int	count;		      /* .. */ +  #if DECDPUN<=4 +  uInt	temp;		      /* .. */ +  #endif + +  discard=len-set->digits;    /* digits to discard */ +  if (discard<=0) {	      /* no digits are being discarded */ +    if (dn->lsu!=lsu) {	      /* copy needed */ +      /* copy the coefficient array to the result number; no shift needed */ +      count=len;	      /* avoids D2U */ +      up=lsu; +      for (target=dn->lsu; count>0; target++, up++, count-=DECDPUN) +	*target=*up; +      dn->digits=len;	      /* set the new length */ +      } +    /* dn->exponent and residue are unchanged, record any inexactitude */ +    if (*residue!=0) *status|=(DEC_Inexact | DEC_Rounded); +    return; +    } + +  /* some digits must be discarded ... */ +  dn->exponent+=discard;      /* maintain numerical value */ +  *status|=DEC_Rounded;	      /* accumulate Rounded status */ +  if (*residue>1) *residue=1; /* previous residue now to right, so reduce */ + +  if (discard>len) {	      /* everything, +1, is being discarded */ +    /* guard digit is 0 */ +    /* residue is all the number [NB could be all 0s] */ +    if (*residue<=0) {	      /* not already positive */ +      count=len;	      /* avoids D2U */ +      for (up=lsu; count>0; up++, count-=DECDPUN) if (*up!=0) { /* found non-0 */ +	*residue=1; +	break;		      /* no need to check any others */ +	} +      } +    if (*residue!=0) *status|=DEC_Inexact; /* record inexactitude */ +    *dn->lsu=0;		      /* coefficient will now be 0 */ +    dn->digits=1;	      /* .. */ +    return; +    } /* total discard */ + +  /* partial discard [most common case] */ +  /* here, at least the first (most significant) discarded digit exists */ + +  /* spin up the number, noting residue during the spin, until get to */ +  /* the Unit with the first discarded digit.  When reach it, extract */ +  /* it and remember its position */ +  count=0; +  for (up=lsu;; up++) { +    count+=DECDPUN; +    if (count>=discard) break; /* full ones all checked */ +    if (*up!=0) *residue=1; +    } /* up */ + +  /* here up -> Unit with first discarded digit */ +  cut=discard-(count-DECDPUN)-1; +  if (cut==DECDPUN-1) {	      /* unit-boundary case (fast) */ +    Unit half=(Unit)powers[DECDPUN]>>1; +    /* set residue directly */ +    if (*up>=half) { +      if (*up>half) *residue=7; +      else *residue+=5;	      /* add sticky bit */ +      } +     else { /* <half */ +      if (*up!=0) *residue=3; /* [else is 0, leave as sticky bit] */ +      } +    if (set->digits<=0) {     /* special for Quantize/Subnormal :-( */ +      *dn->lsu=0;	      /* .. result is 0 */ +      dn->digits=1;	      /* .. */ +      } +     else {		      /* shift to least */ +      count=set->digits;      /* now digits to end up with */ +      dn->digits=count;	      /* set the new length */ +      up++;		      /* move to next */ +      /* on unit boundary, so shift-down copy loop is simple */ +      for (target=dn->lsu; count>0; target++, up++, count-=DECDPUN) +	*target=*up; +      } +    } /* unit-boundary case */ + +   else { /* discard digit is in low digit(s), and not top digit */ +    uInt  discard1;		   /* first discarded digit */ +    uInt  quot, rem;		   /* for divisions */ +    if (cut==0) quot=*up;	   /* is at bottom of unit */ +     else /* cut>0 */ {		   /* it's not at bottom of unit */ +      #if DECDPUN<=4 +	quot=QUOT10(*up, cut); +	rem=*up-quot*powers[cut]; +      #else +	rem=*up%powers[cut]; +	quot=*up/powers[cut]; +      #endif +      if (rem!=0) *residue=1; +      } +    /* discard digit is now at bottom of quot */ +    #if DECDPUN<=4 +      temp=(quot*6554)>>16;	   /* fast /10 */ +      /* Vowels algorithm here not a win (9 instructions) */ +      discard1=quot-X10(temp); +      quot=temp; +    #else +      discard1=quot%10; +      quot=quot/10; +    #endif +    /* here, discard1 is the guard digit, and residue is everything */ +    /* else [use mapping array to accumulate residue safely] */ +    *residue+=resmap[discard1]; +    cut++;			   /* update cut */ +    /* here: up -> Unit of the array with bottom digit */ +    /*	     cut is the division point for each Unit */ +    /*	     quot holds the uncut high-order digits for the current unit */ +    if (set->digits<=0) {	   /* special for Quantize/Subnormal :-( */ +      *dn->lsu=0;		   /* .. result is 0 */ +      dn->digits=1;		   /* .. */ +      } +     else {			   /* shift to least needed */ +      count=set->digits;	   /* now digits to end up with */ +      dn->digits=count;		   /* set the new length */ +      /* shift-copy the coefficient array to the result number */ +      for (target=dn->lsu; ; target++) { +	*target=(Unit)quot; +	count-=(DECDPUN-cut); +	if (count<=0) break; +	up++; +	quot=*up; +	#if DECDPUN<=4 +	  quot=QUOT10(quot, cut); +	  rem=*up-quot*powers[cut]; +	#else +	  rem=quot%powers[cut]; +	  quot=quot/powers[cut]; +	#endif +	*target=(Unit)(*target+rem*powers[DECDPUN-cut]); +	count-=cut; +	if (count<=0) break; +	} /* shift-copy loop */ +      } /* shift to least */ +    } /* not unit boundary */ + +  if (*residue!=0) *status|=DEC_Inexact; /* record inexactitude */ +  return; +  } /* decSetCoeff */ + +/* ------------------------------------------------------------------ */ +/* decApplyRound -- apply pending rounding to a number		      */ +/*								      */ +/*   dn	   is the number, with space for set->digits digits	      */ +/*   set   is the context [for size and rounding mode]		      */ +/*   residue indicates pending rounding, being any accumulated	      */ +/*	   guard and sticky information.  It may be:		      */ +/*	   6-9: rounding digit is >5				      */ +/*	   5:	rounding digit is exactly half-way		      */ +/*	   1-4: rounding digit is <5 and >0			      */ +/*	   0:	the coefficient is exact			      */ +/*	  -1:	as 1, but the hidden digits are subtractive, that     */ +/*		is, of the opposite sign to dn.	 In this case the     */ +/*		coefficient must be non-0.  This case occurs when     */ +/*		subtracting a small number (which can be reduced to   */ +/*		a sticky bit); see decAddOp.			      */ +/*   status is the status accumulator, as usual			      */ +/*								      */ +/* This routine applies rounding while keeping the length of the      */ +/* coefficient constant.  The exponent and status are unchanged	      */ +/* except if:							      */ +/*								      */ +/*   -- the coefficient was increased and is all nines (in which      */ +/*	case Overflow could occur, and is handled directly here so    */ +/*	the caller does not need to re-test for overflow)	      */ +/*								      */ +/*   -- the coefficient was decreased and becomes all nines (in which */ +/*	case Underflow could occur, and is also handled directly).    */ +/*								      */ +/* All fields in dn are updated as required.			      */ +/*								      */ +/* ------------------------------------------------------------------ */ +static void decApplyRound(decNumber *dn, decContext *set, Int residue, +			  uInt *status) { +  Int  bump;		      /* 1 if coefficient needs to be incremented */ +			      /* -1 if coefficient needs to be decremented */ + +  if (residue==0) return;     /* nothing to apply */ + +  bump=0;		      /* assume a smooth ride */ + +  /* now decide whether, and how, to round, depending on mode */ +  switch (set->round) { +    case DEC_ROUND_05UP: {    /* round zero or five up (for reround) */ +      /* This is the same as DEC_ROUND_DOWN unless there is a */ +      /* positive residue and the lsd of dn is 0 or 5, in which case */ +      /* it is bumped; when residue is <0, the number is therefore */ +      /* bumped down unless the final digit was 1 or 6 (in which */ +      /* case it is bumped down and then up -- a no-op) */ +      Int lsd5=*dn->lsu%5;     /* get lsd and quintate */ +      if (residue<0 && lsd5!=1) bump=-1; +       else if (residue>0 && lsd5==0) bump=1; +      /* [bump==1 could be applied directly; use common path for clarity] */ +      break;} /* r-05 */ + +    case DEC_ROUND_DOWN: { +      /* no change, except if negative residue */ +      if (residue<0) bump=-1; +      break;} /* r-d */ + +    case DEC_ROUND_HALF_DOWN: { +      if (residue>5) bump=1; +      break;} /* r-h-d */ + +    case DEC_ROUND_HALF_EVEN: { +      if (residue>5) bump=1;		/* >0.5 goes up */ +       else if (residue==5) {		/* exactly 0.5000... */ +	/* 0.5 goes up iff [new] lsd is odd */ +	if (*dn->lsu & 0x01) bump=1; +	} +      break;} /* r-h-e */ + +    case DEC_ROUND_HALF_UP: { +      if (residue>=5) bump=1; +      break;} /* r-h-u */ + +    case DEC_ROUND_UP: { +      if (residue>0) bump=1; +      break;} /* r-u */ + +    case DEC_ROUND_CEILING: { +      /* same as _UP for positive numbers, and as _DOWN for negatives */ +      /* [negative residue cannot occur on 0] */ +      if (decNumberIsNegative(dn)) { +	if (residue<0) bump=-1; +	} +       else { +	if (residue>0) bump=1; +	} +      break;} /* r-c */ + +    case DEC_ROUND_FLOOR: { +      /* same as _UP for negative numbers, and as _DOWN for positive */ +      /* [negative residue cannot occur on 0] */ +      if (!decNumberIsNegative(dn)) { +	if (residue<0) bump=-1; +	} +       else { +	if (residue>0) bump=1; +	} +      break;} /* r-f */ + +    default: {	    /* e.g., DEC_ROUND_MAX */ +      *status|=DEC_Invalid_context; +      #if DECTRACE || (DECCHECK && DECVERB) +      printf("Unknown rounding mode: %d\n", set->round); +      #endif +      break;} +    } /* switch */ + +  /* now bump the number, up or down, if need be */ +  if (bump==0) return;			     /* no action required */ + +  /* Simply use decUnitAddSub unless bumping up and the number is */ +  /* all nines.	 In this special case set to 100... explicitly */ +  /* and adjust the exponent by one (as otherwise could overflow */ +  /* the array) */ +  /* Similarly handle all-nines result if bumping down. */ +  if (bump>0) { +    Unit *up;				     /* work */ +    uInt count=dn->digits;		     /* digits to be checked */ +    for (up=dn->lsu; ; up++) { +      if (count<=DECDPUN) { +	/* this is the last Unit (the msu) */ +	if (*up!=powers[count]-1) break;     /* not still 9s */ +	/* here if it, too, is all nines */ +	*up=(Unit)powers[count-1];	     /* here 999 -> 100 etc. */ +	for (up=up-1; up>=dn->lsu; up--) *up=0; /* others all to 0 */ +	dn->exponent++;			     /* and bump exponent */ +	/* [which, very rarely, could cause Overflow...] */ +	if ((dn->exponent+dn->digits)>set->emax+1) { +	  decSetOverflow(dn, set, status); +	  } +	return;				     /* done */ +	} +      /* a full unit to check, with more to come */ +      if (*up!=DECDPUNMAX) break;	     /* not still 9s */ +      count-=DECDPUN; +      } /* up */ +    } /* bump>0 */ +   else {				     /* -1 */ +    /* here checking for a pre-bump of 1000... (leading 1, all */ +    /* other digits zero) */ +    Unit *up, *sup;			     /* work */ +    uInt count=dn->digits;		     /* digits to be checked */ +    for (up=dn->lsu; ; up++) { +      if (count<=DECDPUN) { +	/* this is the last Unit (the msu) */ +	if (*up!=powers[count-1]) break;     /* not 100.. */ +	/* here if have the 1000... case */ +	sup=up;				     /* save msu pointer */ +	*up=(Unit)powers[count]-1;	     /* here 100 in msu -> 999 */ +	/* others all to all-nines, too */ +	for (up=up-1; up>=dn->lsu; up--) *up=(Unit)powers[DECDPUN]-1; +	dn->exponent--;			     /* and bump exponent */ + +	/* iff the number was at the subnormal boundary (exponent=etiny) */ +	/* then the exponent is now out of range, so it will in fact get */ +	/* clamped to etiny and the final 9 dropped. */ +	/* printf(">> emin=%d exp=%d sdig=%d\n", set->emin, */ +	/*	  dn->exponent, set->digits); */ +	if (dn->exponent+1==set->emin-set->digits+1) { +	  if (count==1 && dn->digits==1) *sup=0;  /* here 9 -> 0[.9] */ +	   else { +	    *sup=(Unit)powers[count-1]-1;    /* here 999.. in msu -> 99.. */ +	    dn->digits--; +	    } +	  dn->exponent++; +	  *status|=DEC_Underflow | DEC_Subnormal | DEC_Inexact | DEC_Rounded; +	  } +	return;				     /* done */ +	} + +      /* a full unit to check, with more to come */ +      if (*up!=0) break;		     /* not still 0s */ +      count-=DECDPUN; +      } /* up */ + +    } /* bump<0 */ + +  /* Actual bump needed.  Do it. */ +  decUnitAddSub(dn->lsu, D2U(dn->digits), uarrone, 1, 0, dn->lsu, bump); +  } /* decApplyRound */ + +#if DECSUBSET +/* ------------------------------------------------------------------ */ +/* decFinish -- finish processing a number			      */ +/*								      */ +/*   dn is the number						      */ +/*   set is the context						      */ +/*   residue is the rounding accumulator (as in decApplyRound)	      */ +/*   status is the accumulator					      */ +/*								      */ +/* This finishes off the current number by:			      */ +/*    1. If not extended:					      */ +/*	 a. Converting a zero result to clean '0'		      */ +/*	 b. Reducing positive exponents to 0, if would fit in digits  */ +/*    2. Checking for overflow and subnormals (always)		      */ +/* Note this is just Finalize when no subset arithmetic.	      */ +/* All fields are updated as required.				      */ +/* ------------------------------------------------------------------ */ +static void decFinish(decNumber *dn, decContext *set, Int *residue, +		      uInt *status) { +  if (!set->extended) { +    if ISZERO(dn) {		   /* value is zero */ +      dn->exponent=0;		   /* clean exponent .. */ +      dn->bits=0;		   /* .. and sign */ +      return;			   /* no error possible */ +      } +    if (dn->exponent>=0) {	   /* non-negative exponent */ +      /* >0; reduce to integer if possible */ +      if (set->digits >= (dn->exponent+dn->digits)) { +	dn->digits=decShiftToMost(dn->lsu, dn->digits, dn->exponent); +	dn->exponent=0; +	} +      } +    } /* !extended */ + +  decFinalize(dn, set, residue, status); +  } /* decFinish */ +#endif + +/* ------------------------------------------------------------------ */ +/* decFinalize -- final check, clamp, and round of a number	      */ +/*								      */ +/*   dn is the number						      */ +/*   set is the context						      */ +/*   residue is the rounding accumulator (as in decApplyRound)	      */ +/*   status is the status accumulator				      */ +/*								      */ +/* This finishes off the current number by checking for subnormal     */ +/* results, applying any pending rounding, checking for overflow,     */ +/* and applying any clamping.					      */ +/* Underflow and overflow conditions are raised as appropriate.	      */ +/* All fields are updated as required.				      */ +/* ------------------------------------------------------------------ */ +static void decFinalize(decNumber *dn, decContext *set, Int *residue, +			uInt *status) { +  Int shift;				/* shift needed if clamping */ +  Int tinyexp=set->emin-dn->digits+1;	/* precalculate subnormal boundary */ + +  /* Must be careful, here, when checking the exponent as the */ +  /* adjusted exponent could overflow 31 bits [because it may already */ +  /* be up to twice the expected]. */ + +  /* First test for subnormal.	This must be done before any final */ +  /* round as the result could be rounded to Nmin or 0. */ +  if (dn->exponent<=tinyexp) {		/* prefilter */ +    Int comp; +    decNumber nmin; +    /* A very nasty case here is dn == Nmin and residue<0 */ +    if (dn->exponent<tinyexp) { +      /* Go handle subnormals; this will apply round if needed. */ +      decSetSubnormal(dn, set, residue, status); +      return; +      } +    /* Equals case: only subnormal if dn=Nmin and negative residue */ +    decNumberZero(&nmin); +    nmin.lsu[0]=1; +    nmin.exponent=set->emin; +    comp=decCompare(dn, &nmin, 1);		  /* (signless compare) */ +    if (comp==BADINT) {				  /* oops */ +      *status|=DEC_Insufficient_storage;	  /* abandon... */ +      return; +      } +    if (*residue<0 && comp==0) {		  /* neg residue and dn==Nmin */ +      decApplyRound(dn, set, *residue, status);	  /* might force down */ +      decSetSubnormal(dn, set, residue, status); +      return; +      } +    } + +  /* now apply any pending round (this could raise overflow). */ +  if (*residue!=0) decApplyRound(dn, set, *residue, status); + +  /* Check for overflow [redundant in the 'rare' case] or clamp */ +  if (dn->exponent<=set->emax-set->digits+1) return;   /* neither needed */ + + +  /* here when might have an overflow or clamp to do */ +  if (dn->exponent>set->emax-dn->digits+1) {	       /* too big */ +    decSetOverflow(dn, set, status); +    return; +    } +  /* here when the result is normal but in clamp range */ +  if (!set->clamp) return; + +  /* here when need to apply the IEEE exponent clamp (fold-down) */ +  shift=dn->exponent-(set->emax-set->digits+1); + +  /* shift coefficient (if non-zero) */ +  if (!ISZERO(dn)) { +    dn->digits=decShiftToMost(dn->lsu, dn->digits, shift); +    } +  dn->exponent-=shift;	 /* adjust the exponent to match */ +  *status|=DEC_Clamped;	 /* and record the dirty deed */ +  return; +  } /* decFinalize */ + +/* ------------------------------------------------------------------ */ +/* decSetOverflow -- set number to proper overflow value	      */ +/*								      */ +/*   dn is the number (used for sign [only] and result)		      */ +/*   set is the context [used for the rounding mode, etc.]	      */ +/*   status contains the current status to be updated		      */ +/*								      */ +/* This sets the sign of a number and sets its value to either	      */ +/* Infinity or the maximum finite value, depending on the sign of     */ +/* dn and the rounding mode, following IEEE 854 rules.		      */ +/* ------------------------------------------------------------------ */ +static void decSetOverflow(decNumber *dn, decContext *set, uInt *status) { +  Flag needmax=0;		   /* result is maximum finite value */ +  uByte sign=dn->bits&DECNEG;	   /* clean and save sign bit */ + +  if (ISZERO(dn)) {		   /* zero does not overflow magnitude */ +    Int emax=set->emax;			     /* limit value */ +    if (set->clamp) emax-=set->digits-1;     /* lower if clamping */ +    if (dn->exponent>emax) {		     /* clamp required */ +      dn->exponent=emax; +      *status|=DEC_Clamped; +      } +    return; +    } + +  decNumberZero(dn); +  switch (set->round) { +    case DEC_ROUND_DOWN: { +      needmax=1;		   /* never Infinity */ +      break;} /* r-d */ +    case DEC_ROUND_05UP: { +      needmax=1;		   /* never Infinity */ +      break;} /* r-05 */ +    case DEC_ROUND_CEILING: { +      if (sign) needmax=1;	   /* Infinity if non-negative */ +      break;} /* r-c */ +    case DEC_ROUND_FLOOR: { +      if (!sign) needmax=1;	   /* Infinity if negative */ +      break;} /* r-f */ +    default: break;		   /* Infinity in all other cases */ +    } +  if (needmax) { +    decSetMaxValue(dn, set); +    dn->bits=sign;		   /* set sign */ +    } +   else dn->bits=sign|DECINF;	   /* Value is +/-Infinity */ +  *status|=DEC_Overflow | DEC_Inexact | DEC_Rounded; +  } /* decSetOverflow */ + +/* ------------------------------------------------------------------ */ +/* decSetMaxValue -- set number to +Nmax (maximum normal value)	      */ +/*								      */ +/*   dn is the number to set					      */ +/*   set is the context [used for digits and emax]		      */ +/*								      */ +/* This sets the number to the maximum positive value.		      */ +/* ------------------------------------------------------------------ */ +static void decSetMaxValue(decNumber *dn, decContext *set) { +  Unit *up;			   /* work */ +  Int count=set->digits;	   /* nines to add */ +  dn->digits=count; +  /* fill in all nines to set maximum value */ +  for (up=dn->lsu; ; up++) { +    if (count>DECDPUN) *up=DECDPUNMAX;	/* unit full o'nines */ +     else {				/* this is the msu */ +      *up=(Unit)(powers[count]-1); +      break; +      } +    count-=DECDPUN;		   /* filled those digits */ +    } /* up */ +  dn->bits=0;			   /* + sign */ +  dn->exponent=set->emax-set->digits+1; +  } /* decSetMaxValue */ + +/* ------------------------------------------------------------------ */ +/* decSetSubnormal -- process value whose exponent is <Emin	      */ +/*								      */ +/*   dn is the number (used as input as well as output; it may have   */ +/*	   an allowed subnormal value, which may need to be rounded)  */ +/*   set is the context [used for the rounding mode]		      */ +/*   residue is any pending residue				      */ +/*   status contains the current status to be updated		      */ +/*								      */ +/* If subset mode, set result to zero and set Underflow flags.	      */ +/*								      */ +/* Value may be zero with a low exponent; this does not set Subnormal */ +/* but the exponent will be clamped to Etiny.			      */ +/*								      */ +/* Otherwise ensure exponent is not out of range, and round as	      */ +/* necessary.  Underflow is set if the result is Inexact.	      */ +/* ------------------------------------------------------------------ */ +static void decSetSubnormal(decNumber *dn, decContext *set, Int *residue, +			    uInt *status) { +  decContext workset;	      /* work */ +  Int	     etiny, adjust;   /* .. */ + +  #if DECSUBSET +  /* simple set to zero and 'hard underflow' for subset */ +  if (!set->extended) { +    decNumberZero(dn); +    /* always full overflow */ +    *status|=DEC_Underflow | DEC_Subnormal | DEC_Inexact | DEC_Rounded; +    return; +    } +  #endif + +  /* Full arithmetic -- allow subnormals, rounded to minimum exponent */ +  /* (Etiny) if needed */ +  etiny=set->emin-(set->digits-1);	/* smallest allowed exponent */ + +  if ISZERO(dn) {			/* value is zero */ +    /* residue can never be non-zero here */ +    #if DECCHECK +      if (*residue!=0) { +	printf("++ Subnormal 0 residue %ld\n", (LI)*residue); +	*status|=DEC_Invalid_operation; +	} +    #endif +    if (dn->exponent<etiny) {		/* clamp required */ +      dn->exponent=etiny; +      *status|=DEC_Clamped; +      } +    return; +    } + +  *status|=DEC_Subnormal;		/* have a non-zero subnormal */ +  adjust=etiny-dn->exponent;		/* calculate digits to remove */ +  if (adjust<=0) {			/* not out of range; unrounded */ +    /* residue can never be non-zero here, except in the Nmin-residue */ +    /* case (which is a subnormal result), so can take fast-path here */ +    /* it may already be inexact (from setting the coefficient) */ +    if (*status&DEC_Inexact) *status|=DEC_Underflow; +    return; +    } + +  /* adjust>0, so need to rescale the result so exponent becomes Etiny */ +  /* [this code is similar to that in rescale] */ +  workset=*set;				/* clone rounding, etc. */ +  workset.digits=dn->digits-adjust;	/* set requested length */ +  workset.emin-=adjust;			/* and adjust emin to match */ +  /* [note that the latter can be <1, here, similar to Rescale case] */ +  decSetCoeff(dn, &workset, dn->lsu, dn->digits, residue, status); +  decApplyRound(dn, &workset, *residue, status); + +  /* Use 754R/854 default rule: Underflow is set iff Inexact */ +  /* [independent of whether trapped] */ +  if (*status&DEC_Inexact) *status|=DEC_Underflow; + +  /* if rounded up a 999s case, exponent will be off by one; adjust */ +  /* back if so [it will fit, because it was shortened earlier] */ +  if (dn->exponent>etiny) { +    dn->digits=decShiftToMost(dn->lsu, dn->digits, 1); +    dn->exponent--;			/* (re)adjust the exponent. */ +    } + +  /* if rounded to zero, it is by definition clamped... */ +  if (ISZERO(dn)) *status|=DEC_Clamped; +  } /* decSetSubnormal */ + +/* ------------------------------------------------------------------ */ +/* decCheckMath - check entry conditions for a math function	      */ +/*								      */ +/*   This checks the context and the operand			      */ +/*								      */ +/*   rhs is the operand to check				      */ +/*   set is the context to check				      */ +/*   status is unchanged if both are good			      */ +/*								      */ +/* returns non-zero if status is changed, 0 otherwise		      */ +/*								      */ +/* Restrictions enforced:					      */ +/*								      */ +/*   digits, emax, and -emin in the context must be less than	      */ +/*   DEC_MAX_MATH (999999), and A must be within these bounds if      */ +/*   non-zero.	Invalid_operation is set in the status if a	      */ +/*   restriction is violated.					      */ +/* ------------------------------------------------------------------ */ +static uInt decCheckMath(const decNumber *rhs, decContext *set, +			 uInt *status) { +  uInt save=*status;			     /* record */ +  if (set->digits>DEC_MAX_MATH +   || set->emax>DEC_MAX_MATH +   || -set->emin>DEC_MAX_MATH) *status|=DEC_Invalid_context; +   else if ((rhs->digits>DEC_MAX_MATH +     || rhs->exponent+rhs->digits>DEC_MAX_MATH+1 +     || rhs->exponent+rhs->digits<2*(1-DEC_MAX_MATH)) +     && !ISZERO(rhs)) *status|=DEC_Invalid_operation; +  return (*status!=save); +  } /* decCheckMath */ + +/* ------------------------------------------------------------------ */ +/* decGetInt -- get integer from a number			      */ +/*								      */ +/*   dn is the number [which will not be altered]		      */ +/*								      */ +/*   returns one of:						      */ +/*     BADINT if there is a non-zero fraction			      */ +/*     the converted integer					      */ +/*     BIGEVEN if the integer is even and magnitude > 2*10**9	      */ +/*     BIGODD  if the integer is odd  and magnitude > 2*10**9	      */ +/*								      */ +/* This checks and gets a whole number from the input decNumber.      */ +/* The sign can be determined from dn by the caller when BIGEVEN or   */ +/* BIGODD is returned.						      */ +/* ------------------------------------------------------------------ */ +static Int decGetInt(const decNumber *dn) { +  Int  theInt;				/* result accumulator */ +  const Unit *up;			/* work */ +  Int  got;				/* digits (real or not) processed */ +  Int  ilength=dn->digits+dn->exponent; /* integral length */ +  Flag neg=decNumberIsNegative(dn);	/* 1 if -ve */ + +  /* The number must be an integer that fits in 10 digits */ +  /* Assert, here, that 10 is enough for any rescale Etiny */ +  #if DEC_MAX_EMAX > 999999999 +    #error GetInt may need updating [for Emax] +  #endif +  #if DEC_MIN_EMIN < -999999999 +    #error GetInt may need updating [for Emin] +  #endif +  if (ISZERO(dn)) return 0;		/* zeros are OK, with any exponent */ + +  up=dn->lsu;				/* ready for lsu */ +  theInt=0;				/* ready to accumulate */ +  if (dn->exponent>=0) {		/* relatively easy */ +    /* no fractional part [usual]; allow for positive exponent */ +    got=dn->exponent; +    } +   else { /* -ve exponent; some fractional part to check and discard */ +    Int count=-dn->exponent;		/* digits to discard */ +    /* spin up whole units until reach the Unit with the unit digit */ +    for (; count>=DECDPUN; up++) { +      if (*up!=0) return BADINT;	/* non-zero Unit to discard */ +      count-=DECDPUN; +      } +    if (count==0) got=0;		/* [a multiple of DECDPUN] */ +     else {				/* [not multiple of DECDPUN] */ +      Int rem;				/* work */ +      /* slice off fraction digits and check for non-zero */ +      #if DECDPUN<=4 +	theInt=QUOT10(*up, count); +	rem=*up-theInt*powers[count]; +      #else +	rem=*up%powers[count];		/* slice off discards */ +	theInt=*up/powers[count]; +      #endif +      if (rem!=0) return BADINT;	/* non-zero fraction */ +      /* it looks good */ +      got=DECDPUN-count;		/* number of digits so far */ +      up++;				/* ready for next */ +      } +    } +  /* now it's known there's no fractional part */ + +  /* tricky code now, to accumulate up to 9.3 digits */ +  if (got==0) {theInt=*up; got+=DECDPUN; up++;} /* ensure lsu is there */ + +  if (ilength<11) { +    Int save=theInt; +    /* collect any remaining unit(s) */ +    for (; got<ilength; up++) { +      theInt+=*up*powers[got]; +      got+=DECDPUN; +      } +    if (ilength==10) {			/* need to check for wrap */ +      if (theInt/(Int)powers[got-DECDPUN]!=(Int)*(up-1)) ilength=11; +	 /* [that test also disallows the BADINT result case] */ +       else if (neg && theInt>1999999997) ilength=11; +       else if (!neg && theInt>999999999) ilength=11; +      if (ilength==11) theInt=save;	/* restore correct low bit */ +      } +    } + +  if (ilength>10) {			/* too big */ +    if (theInt&1) return BIGODD;	/* bottom bit 1 */ +    return BIGEVEN;			/* bottom bit 0 */ +    } + +  if (neg) theInt=-theInt;		/* apply sign */ +  return theInt; +  } /* decGetInt */ + +/* ------------------------------------------------------------------ */ +/* decDecap -- decapitate the coefficient of a number		      */ +/*								      */ +/*   dn	  is the number to be decapitated			      */ +/*   drop is the number of digits to be removed from the left of dn;  */ +/*     this must be <= dn->digits (if equal, the coefficient is	      */ +/*     set to 0)						      */ +/*								      */ +/* Returns dn; dn->digits will be <= the initial digits less drop     */ +/* (after removing drop digits there may be leading zero digits	      */ +/* which will also be removed).	 Only dn->lsu and dn->digits change.  */ +/* ------------------------------------------------------------------ */ +static decNumber *decDecap(decNumber *dn, Int drop) { +  Unit *msu;				/* -> target cut point */ +  Int cut;				/* work */ +  if (drop>=dn->digits) {		/* losing the whole thing */ +    #if DECCHECK +    if (drop>dn->digits) +      printf("decDecap called with drop>digits [%ld>%ld]\n", +	     (LI)drop, (LI)dn->digits); +    #endif +    dn->lsu[0]=0; +    dn->digits=1; +    return dn; +    } +  msu=dn->lsu+D2U(dn->digits-drop)-1;	/* -> likely msu */ +  cut=MSUDIGITS(dn->digits-drop);	/* digits to be in use in msu */ +  if (cut!=DECDPUN) *msu%=powers[cut];	/* clear left digits */ +  /* that may have left leading zero digits, so do a proper count... */ +  dn->digits=decGetDigits(dn->lsu, msu-dn->lsu+1); +  return dn; +  } /* decDecap */ + +/* ------------------------------------------------------------------ */ +/* decBiStr -- compare string with pairwise options		      */ +/*								      */ +/*   targ is the string to compare				      */ +/*   str1 is one of the strings to compare against (length may be 0)  */ +/*   str2 is the other; it must be the same length as str1	      */ +/*								      */ +/*   returns 1 if strings compare equal, (that is, it is the same     */ +/*   length as str1 and str2, and each character of targ is in either */ +/*   str1 or str2 in the corresponding position), or 0 otherwise      */ +/*								      */ +/* This is used for generic caseless compare, including the awkward   */ +/* case of the Turkish dotted and dotless Is.  Use as (for example):  */ +/*   if (decBiStr(test, "mike", "MIKE")) ...			      */ +/* ------------------------------------------------------------------ */ +static Flag decBiStr(const char *targ, const char *str1, const char *str2) { +  for (;;targ++, str1++, str2++) { +    if (*targ!=*str1 && *targ!=*str2) return 0; +    /* *targ has a match in one (or both, if terminator) */ +    if (*targ=='\0') break; +    } /* forever */ +  return 1; +  } /* decBiStr */ + +/* ------------------------------------------------------------------ */ +/* decNaNs -- handle NaN operand or operands			      */ +/*								      */ +/*   res     is the result number				      */ +/*   lhs     is the first operand				      */ +/*   rhs     is the second operand, or NULL if none		      */ +/*   context is used to limit payload length			      */ +/*   status  contains the current status			      */ +/*   returns res in case convenient				      */ +/*								      */ +/* Called when one or both operands is a NaN, and propagates the      */ +/* appropriate result to res.  When an sNaN is found, it is changed   */ +/* to a qNaN and Invalid operation is set.			      */ +/* ------------------------------------------------------------------ */ +static decNumber * decNaNs(decNumber *res, const decNumber *lhs, +			   const decNumber *rhs, decContext *set, +			   uInt *status) { +  /* This decision tree ends up with LHS being the source pointer, */ +  /* and status updated if need be */ +  if (lhs->bits & DECSNAN) +    *status|=DEC_Invalid_operation | DEC_sNaN; +   else if (rhs==NULL); +   else if (rhs->bits & DECSNAN) { +    lhs=rhs; +    *status|=DEC_Invalid_operation | DEC_sNaN; +    } +   else if (lhs->bits & DECNAN); +   else lhs=rhs; + +  /* propagate the payload */ +  if (lhs->digits<=set->digits) decNumberCopy(res, lhs); /* easy */ +   else { /* too long */ +    const Unit *ul; +    Unit *ur, *uresp1; +    /* copy safe number of units, then decapitate */ +    res->bits=lhs->bits;		/* need sign etc. */ +    uresp1=res->lsu+D2U(set->digits); +    for (ur=res->lsu, ul=lhs->lsu; ur<uresp1; ur++, ul++) *ur=*ul; +    res->digits=D2U(set->digits)*DECDPUN; +    /* maybe still too long */ +    if (res->digits>set->digits) decDecap(res, res->digits-set->digits); +    } + +  res->bits&=~DECSNAN;	      /* convert any sNaN to NaN, while */ +  res->bits|=DECNAN;	      /* .. preserving sign */ +  res->exponent=0;	      /* clean exponent */ +			      /* [coefficient was copied/decapitated] */ +  return res; +  } /* decNaNs */ + +/* ------------------------------------------------------------------ */ +/* decStatus -- apply non-zero status				      */ +/*								      */ +/*   dn	    is the number to set if error			      */ +/*   status contains the current status (not yet in context)	      */ +/*   set    is the context					      */ +/*								      */ +/* If the status is an error status, the number is set to a NaN,      */ +/* unless the error was an overflow, divide-by-zero, or underflow,    */ +/* in which case the number will have already been set.		      */ +/*								      */ +/* The context status is then updated with the new status.  Note that */ +/* this may raise a signal, so control may never return from this     */ +/* routine (hence resources must be recovered before it is called).   */ +/* ------------------------------------------------------------------ */ +static void decStatus(decNumber *dn, uInt status, decContext *set) { +  if (status & DEC_NaNs) {		/* error status -> NaN */ +    /* if cause was an sNaN, clear and propagate [NaN is already set up] */ +    if (status & DEC_sNaN) status&=~DEC_sNaN; +     else { +      decNumberZero(dn);		/* other error: clean throughout */ +      dn->bits=DECNAN;			/* and make a quiet NaN */ +      } +    } +  decContextSetStatus(set, status);	/* [may not return] */ +  return; +  } /* decStatus */ + +/* ------------------------------------------------------------------ */ +/* decGetDigits -- count digits in a Units array		      */ +/*								      */ +/*   uar is the Unit array holding the number (this is often an	      */ +/*	    accumulator of some sort)				      */ +/*   len is the length of the array in units [>=1]		      */ +/*								      */ +/*   returns the number of (significant) digits in the array	      */ +/*								      */ +/* All leading zeros are excluded, except the last if the array has   */ +/* only zero Units.						      */ +/* ------------------------------------------------------------------ */ +/* This may be called twice during some operations. */ +static Int decGetDigits(Unit *uar, Int len) { +  Unit *up=uar+(len-1);		   /* -> msu */ +  Int  digits=(len-1)*DECDPUN+1;   /* possible digits excluding msu */ +  #if DECDPUN>4 +  uInt const *pow;		   /* work */ +  #endif +				   /* (at least 1 in final msu) */ +  #if DECCHECK +  if (len<1) printf("decGetDigits called with len<1 [%ld]\n", (LI)len); +  #endif + +  for (; up>=uar; up--) { +    if (*up==0) {		   /* unit is all 0s */ +      if (digits==1) break;	   /* a zero has one digit */ +      digits-=DECDPUN;		   /* adjust for 0 unit */ +      continue;} +    /* found the first (most significant) non-zero Unit */ +    #if DECDPUN>1		   /* not done yet */ +    if (*up<10) break;		   /* is 1-9 */ +    digits++; +    #if DECDPUN>2		   /* not done yet */ +    if (*up<100) break;		   /* is 10-99 */ +    digits++; +    #if DECDPUN>3		   /* not done yet */ +    if (*up<1000) break;	   /* is 100-999 */ +    digits++; +    #if DECDPUN>4		   /* count the rest ... */ +    for (pow=&powers[4]; *up>=*pow; pow++) digits++; +    #endif +    #endif +    #endif +    #endif +    break; +    } /* up */ +  return digits; +  } /* decGetDigits */ + +#if DECTRACE | DECCHECK +/* ------------------------------------------------------------------ */ +/* decNumberShow -- display a number [debug aid]		      */ +/*   dn is the number to show					      */ +/*								      */ +/* Shows: sign, exponent, coefficient (msu first), digits	      */ +/*    or: sign, special-value					      */ +/* ------------------------------------------------------------------ */ +/* this is public so other modules can use it */ +void decNumberShow(const decNumber *dn) { +  const Unit *up;		   /* work */ +  uInt u, d;			   /* .. */ +  Int cut;			   /* .. */ +  char isign='+';		   /* main sign */ +  if (dn==NULL) { +    printf("NULL\n"); +    return;} +  if (decNumberIsNegative(dn)) isign='-'; +  printf(" >> %c ", isign); +  if (dn->bits&DECSPECIAL) {	   /* Is a special value */ +    if (decNumberIsInfinite(dn)) printf("Infinity"); +     else {				     /* a NaN */ +      if (dn->bits&DECSNAN) printf("sNaN");  /* signalling NaN */ +       else printf("NaN"); +      } +    /* if coefficient and exponent are 0, no more to do */ +    if (dn->exponent==0 && dn->digits==1 && *dn->lsu==0) { +      printf("\n"); +      return;} +    /* drop through to report other information */ +    printf(" "); +    } + +  /* now carefully display the coefficient */ +  up=dn->lsu+D2U(dn->digits)-1;		/* msu */ +  printf("%ld", (LI)*up); +  for (up=up-1; up>=dn->lsu; up--) { +    u=*up; +    printf(":"); +    for (cut=DECDPUN-1; cut>=0; cut--) { +      d=u/powers[cut]; +      u-=d*powers[cut]; +      printf("%ld", (LI)d); +      } /* cut */ +    } /* up */ +  if (dn->exponent!=0) { +    char esign='+'; +    if (dn->exponent<0) esign='-'; +    printf(" E%c%ld", esign, (LI)abs(dn->exponent)); +    } +  printf(" [%ld]\n", (LI)dn->digits); +  } /* decNumberShow */ +#endif + +#if DECTRACE || DECCHECK +/* ------------------------------------------------------------------ */ +/* decDumpAr -- display a unit array [debug/check aid]		      */ +/*   name is a single-character tag name			      */ +/*   ar	  is the array to display				      */ +/*   len  is the length of the array in Units			      */ +/* ------------------------------------------------------------------ */ +static void decDumpAr(char name, const Unit *ar, Int len) { +  Int i; +  const char *spec; +  #if DECDPUN==9 +    spec="%09d "; +  #elif DECDPUN==8 +    spec="%08d "; +  #elif DECDPUN==7 +    spec="%07d "; +  #elif DECDPUN==6 +    spec="%06d "; +  #elif DECDPUN==5 +    spec="%05d "; +  #elif DECDPUN==4 +    spec="%04d "; +  #elif DECDPUN==3 +    spec="%03d "; +  #elif DECDPUN==2 +    spec="%02d "; +  #else +    spec="%d "; +  #endif +  printf("  :%c: ", name); +  for (i=len-1; i>=0; i--) { +    if (i==len-1) printf("%ld ", (LI)ar[i]); +     else printf(spec, ar[i]); +    } +  printf("\n"); +  return;} +#endif + +#if DECCHECK +/* ------------------------------------------------------------------ */ +/* decCheckOperands -- check operand(s) to a routine		      */ +/*   res is the result structure (not checked; it will be set to      */ +/*	    quiet NaN if error found (and it is not NULL))	      */ +/*   lhs is the first operand (may be DECUNRESU)		      */ +/*   rhs is the second (may be DECUNUSED)			      */ +/*   set is the context (may be DECUNCONT)			      */ +/*   returns 0 if both operands, and the context are clean, or 1      */ +/*     otherwise (in which case the context will show an error,	      */ +/*     unless NULL).  Note that res is not cleaned; caller should     */ +/*     handle this so res=NULL case is safe.			      */ +/* The caller is expected to abandon immediately if 1 is returned.    */ +/* ------------------------------------------------------------------ */ +static Flag decCheckOperands(decNumber *res, const decNumber *lhs, +			     const decNumber *rhs, decContext *set) { +  Flag bad=0; +  if (set==NULL) {		   /* oops; hopeless */ +    #if DECTRACE || DECVERB +    printf("Reference to context is NULL.\n"); +    #endif +    bad=1; +    return 1;} +   else if (set!=DECUNCONT +     && (set->digits<1 || set->round>=DEC_ROUND_MAX)) { +    bad=1; +    #if DECTRACE || DECVERB +    printf("Bad context [digits=%ld round=%ld].\n", +	   (LI)set->digits, (LI)set->round); +    #endif +    } +   else { +    if (res==NULL) { +      bad=1; +      #if DECTRACE +      /* this one not DECVERB as standard tests include NULL */ +      printf("Reference to result is NULL.\n"); +      #endif +      } +    if (!bad && lhs!=DECUNUSED) bad=(decCheckNumber(lhs)); +    if (!bad && rhs!=DECUNUSED) bad=(decCheckNumber(rhs)); +    } +  if (bad) { +    if (set!=DECUNCONT) decContextSetStatus(set, DEC_Invalid_operation); +    if (res!=DECUNRESU && res!=NULL) { +      decNumberZero(res); +      res->bits=DECNAN;	      /* qNaN */ +      } +    } +  return bad; +  } /* decCheckOperands */ + +/* ------------------------------------------------------------------ */ +/* decCheckNumber -- check a number				      */ +/*   dn is the number to check					      */ +/*   returns 0 if the number is clean, or 1 otherwise		      */ +/*								      */ +/* The number is considered valid if it could be a result from some   */ +/* operation in some valid context.				      */ +/* ------------------------------------------------------------------ */ +static Flag decCheckNumber(const decNumber *dn) { +  const Unit *up;	      /* work */ +  uInt maxuint;		      /* .. */ +  Int ae, d, digits;	      /* .. */ +  Int emin, emax;	      /* .. */ + +  if (dn==NULL) {	      /* hopeless */ +    #if DECTRACE +    /* this one not DECVERB as standard tests include NULL */ +    printf("Reference to decNumber is NULL.\n"); +    #endif +    return 1;} + +  /* check special values */ +  if (dn->bits & DECSPECIAL) { +    if (dn->exponent!=0) { +      #if DECTRACE || DECVERB +      printf("Exponent %ld (not 0) for a special value [%02x].\n", +	     (LI)dn->exponent, dn->bits); +      #endif +      return 1;} + +    /* 2003.09.08: NaNs may now have coefficients, so next tests Inf only */ +    if (decNumberIsInfinite(dn)) { +      if (dn->digits!=1) { +	#if DECTRACE || DECVERB +	printf("Digits %ld (not 1) for an infinity.\n", (LI)dn->digits); +	#endif +	return 1;} +      if (*dn->lsu!=0) { +	#if DECTRACE || DECVERB +	printf("LSU %ld (not 0) for an infinity.\n", (LI)*dn->lsu); +	#endif +	decDumpAr('I', dn->lsu, D2U(dn->digits)); +	return 1;} +      } /* Inf */ +    /* 2002.12.26: negative NaNs can now appear through proposed IEEE */ +    /*		   concrete formats (decimal64, etc.). */ +    return 0; +    } + +  /* check the coefficient */ +  if (dn->digits<1 || dn->digits>DECNUMMAXP) { +    #if DECTRACE || DECVERB +    printf("Digits %ld in number.\n", (LI)dn->digits); +    #endif +    return 1;} + +  d=dn->digits; + +  for (up=dn->lsu; d>0; up++) { +    if (d>DECDPUN) maxuint=DECDPUNMAX; +     else {		      /* reached the msu */ +      maxuint=powers[d]-1; +      if (dn->digits>1 && *up<powers[d-1]) { +	#if DECTRACE || DECVERB +	printf("Leading 0 in number.\n"); +	decNumberShow(dn); +	#endif +	return 1;} +      } +    if (*up>maxuint) { +      #if DECTRACE || DECVERB +      printf("Bad Unit [%08lx] in %ld-digit number at offset %ld [maxuint %ld].\n", +	      (LI)*up, (LI)dn->digits, (LI)(up-dn->lsu), (LI)maxuint); +      #endif +      return 1;} +    d-=DECDPUN; +    } + +  /* check the exponent.  Note that input operands can have exponents */ +  /* which are out of the set->emin/set->emax and set->digits range */ +  /* (just as they can have more digits than set->digits). */ +  ae=dn->exponent+dn->digits-1;	   /* adjusted exponent */ +  emax=DECNUMMAXE; +  emin=DECNUMMINE; +  digits=DECNUMMAXP; +  if (ae<emin-(digits-1)) { +    #if DECTRACE || DECVERB +    printf("Adjusted exponent underflow [%ld].\n", (LI)ae); +    decNumberShow(dn); +    #endif +    return 1;} +  if (ae>+emax) { +    #if DECTRACE || DECVERB +    printf("Adjusted exponent overflow [%ld].\n", (LI)ae); +    decNumberShow(dn); +    #endif +    return 1;} + +  return 0;		 /* it's OK */ +  } /* decCheckNumber */ + +/* ------------------------------------------------------------------ */ +/* decCheckInexact -- check a normal finite inexact result has digits */ +/*   dn is the number to check					      */ +/*   set is the context (for status and precision)		      */ +/*   sets Invalid operation, etc., if some digits are missing	      */ +/* [this check is not made for DECSUBSET compilation or when	      */ +/* subnormal is not set]					      */ +/* ------------------------------------------------------------------ */ +static void decCheckInexact(const decNumber *dn, decContext *set) { +  #if !DECSUBSET && DECEXTFLAG +    if ((set->status & (DEC_Inexact|DEC_Subnormal))==DEC_Inexact +     && (set->digits!=dn->digits) && !(dn->bits & DECSPECIAL)) { +      #if DECTRACE || DECVERB +      printf("Insufficient digits [%ld] on normal Inexact result.\n", +	     (LI)dn->digits); +      decNumberShow(dn); +      #endif +      decContextSetStatus(set, DEC_Invalid_operation); +      } +  #else +    /* next is a noop for quiet compiler */ +    if (dn!=NULL && dn->digits==0) set->status|=DEC_Invalid_operation; +  #endif +  return; +  } /* decCheckInexact */ +#endif + +#if DECALLOC +#undef malloc +#undef free +/* ------------------------------------------------------------------ */ +/* decMalloc -- accountable allocation routine			      */ +/*   n is the number of bytes to allocate			      */ +/*								      */ +/* Semantics is the same as the stdlib malloc routine, but bytes      */ +/* allocated are accounted for globally, and corruption fences are    */ +/* added before and after the 'actual' storage.			      */ +/* ------------------------------------------------------------------ */ +/* This routine allocates storage with an extra twelve bytes; 8 are   */ +/* at the start and hold:					      */ +/*   0-3 the original length requested				      */ +/*   4-7 buffer corruption detection fence (DECFENCE, x4)	      */ +/* The 4 bytes at the end also hold a corruption fence (DECFENCE, x4) */ +/* ------------------------------------------------------------------ */ +static void *decMalloc(size_t n) { +  uInt	size=n+12;		   /* true size */ +  void	*alloc;			   /* -> allocated storage */ +  uInt	*j;			   /* work */ +  uByte *b, *b0;		   /* .. */ + +  alloc=malloc(size);		   /* -> allocated storage */ +  if (alloc==NULL) return NULL;	   /* out of strorage */ +  b0=(uByte *)alloc;		   /* as bytes */ +  decAllocBytes+=n;		   /* account for storage */ +  j=(uInt *)alloc;		   /* -> first four bytes */ +  *j=n;				   /* save n */ +  /* printf(" alloc ++ dAB: %ld (%d)\n", decAllocBytes, n); */ +  for (b=b0+4; b<b0+8; b++) *b=DECFENCE; +  for (b=b0+n+8; b<b0+n+12; b++) *b=DECFENCE; +  return b0+8;			   /* -> play area */ +  } /* decMalloc */ + +/* ------------------------------------------------------------------ */ +/* decFree -- accountable free routine				      */ +/*   alloc is the storage to free				      */ +/*								      */ +/* Semantics is the same as the stdlib malloc routine, except that    */ +/* the global storage accounting is updated and the fences are	      */ +/* checked to ensure that no routine has written 'out of bounds'.     */ +/* ------------------------------------------------------------------ */ +/* This routine first checks that the fences have not been corrupted. */ +/* It then frees the storage using the 'truw' storage address (that   */ +/* is, offset by 8).						      */ +/* ------------------------------------------------------------------ */ +static void decFree(void *alloc) { +  uInt	*j, n;			   /* pointer, original length */ +  uByte *b, *b0;		   /* work */ + +  if (alloc==NULL) return;	   /* allowed; it's a nop */ +  b0=(uByte *)alloc;		   /* as bytes */ +  b0-=8;			   /* -> true start of storage */ +  j=(uInt *)b0;			   /* -> first four bytes */ +  n=*j;				   /* lift */ +  for (b=b0+4; b<b0+8; b++) if (*b!=DECFENCE) +    printf("=== Corrupt byte [%02x] at offset %d from %ld ===\n", *b, +	   b-b0-8, (Int)b0); +  for (b=b0+n+8; b<b0+n+12; b++) if (*b!=DECFENCE) +    printf("=== Corrupt byte [%02x] at offset +%d from %ld, n=%ld ===\n", *b, +	   b-b0-8, (Int)b0, n); +  free(b0);			   /* drop the storage */ +  decAllocBytes-=n;		   /* account for storage */ +  /* printf(" free -- dAB: %d (%d)\n", decAllocBytes, -n); */ +  } /* decFree */ +#define malloc(a) decMalloc(a) +#define free(a) decFree(a) +#endif diff --git a/libdecnumber/dpd/decimal128.c b/libdecnumber/dpd/decimal128.c new file mode 100644 index 00000000..7551b7ca --- /dev/null +++ b/libdecnumber/dpd/decimal128.c @@ -0,0 +1,564 @@ +/* Decimal 128-bit format module for the decNumber C Library. +   Copyright (C) 2005, 2007 Free Software Foundation, Inc. +   Contributed by IBM Corporation.  Author Mike Cowlishaw. + +   This file is part of GCC. + +   GCC is free software; you can redistribute it and/or modify it under +   the terms of the GNU General Public License as published by the Free +   Software Foundation; either version 2, or (at your option) any later +   version. + +   In addition to the permissions in the GNU General Public License, +   the Free Software Foundation gives you unlimited permission to link +   the compiled version of this file into combinations with other +   programs, and to distribute those combinations without any +   restriction coming from the use of this file.  (The General Public +   License restrictions do apply in other respects; for example, they +   cover modification of the file, and distribution when not linked +   into a combine executable.) + +   GCC is distributed in the hope that it will be useful, but WITHOUT ANY +   WARRANTY; without even the implied warranty of MERCHANTABILITY or +   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License +   for more details. + +   You should have received a copy of the GNU General Public License +   along with GCC; see the file COPYING.  If not, write to the Free +   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +   02110-1301, USA.  */ + +/* ------------------------------------------------------------------ */ +/* Decimal 128-bit format module				      */ +/* ------------------------------------------------------------------ */ +/* This module comprises the routines for decimal128 format numbers.  */ +/* Conversions are supplied to and from decNumber and String.	      */ +/*								      */ +/* This is used when decNumber provides operations, either for all    */ +/* operations or as a proxy between decNumber and decSingle.	      */ +/*								      */ +/* Error handling is the same as decNumber (qv.).		      */ +/* ------------------------------------------------------------------ */ +#include <string.h>	      /* [for memset/memcpy] */ +#include <stdio.h>	      /* [for printf] */ + +#include "libdecnumber/dconfig.h" +#define	 DECNUMDIGITS 34      /* make decNumbers with space for 34 */ +#include "libdecnumber/decNumber.h" +#include "libdecnumber/decNumberLocal.h" +#include "libdecnumber/dpd/decimal128.h" + +/* Utility routines and tables [in decimal64.c] */ +extern const uInt   COMBEXP[32], COMBMSD[32]; +extern const uByte  BIN2CHAR[4001]; + +extern void decDigitsFromDPD(decNumber *, const uInt *, Int); +extern void decDigitsToDPD(const decNumber *, uInt *, Int); + +#if DECTRACE || DECCHECK +void decimal128Show(const decimal128 *);	  /* for debug */ +extern void decNumberShow(const decNumber *);	  /* .. */ +#endif + +/* Useful macro */ +/* Clear a structure (e.g., a decNumber) */ +#define DEC_clear(d) memset(d, 0, sizeof(*d)) + +/* ------------------------------------------------------------------ */ +/* decimal128FromNumber -- convert decNumber to decimal128	      */ +/*								      */ +/*   ds is the target decimal128				      */ +/*   dn is the source number (assumed valid)			      */ +/*   set is the context, used only for reporting errors		      */ +/*								      */ +/* The set argument is used only for status reporting and for the     */ +/* rounding mode (used if the coefficient is more than DECIMAL128_Pmax*/ +/* digits or an overflow is detected).	If the exponent is out of the */ +/* valid range then Overflow or Underflow will be raised.	      */ +/* After Underflow a subnormal result is possible.		      */ +/*								      */ +/* DEC_Clamped is set if the number has to be 'folded down' to fit,   */ +/* by reducing its exponent and multiplying the coefficient by a      */ +/* power of ten, or if the exponent on a zero had to be clamped.      */ +/* ------------------------------------------------------------------ */ +decimal128 * decimal128FromNumber(decimal128 *d128, const decNumber *dn, +				  decContext *set) { +  uInt status=0;		   /* status accumulator */ +  Int ae;			   /* adjusted exponent */ +  decNumber  dw;		   /* work */ +  decContext dc;		   /* .. */ +  uInt *pu;			   /* .. */ +  uInt comb, exp;		   /* .. */ +  uInt targar[4]={0,0,0,0};	   /* target 128-bit */ +  #define targhi targar[3]	   /* name the word with the sign */ +  #define targmh targar[2]	   /* name the words */ +  #define targml targar[1]	   /* .. */ +  #define targlo targar[0]	   /* .. */ + +  /* If the number has too many digits, or the exponent could be */ +  /* out of range then reduce the number under the appropriate */ +  /* constraints.  This could push the number to Infinity or zero, */ +  /* so this check and rounding must be done before generating the */ +  /* decimal128] */ +  ae=dn->exponent+dn->digits-1;		     /* [0 if special] */ +  if (dn->digits>DECIMAL128_Pmax	     /* too many digits */ +   || ae>DECIMAL128_Emax		     /* likely overflow */ +   || ae<DECIMAL128_Emin) {		     /* likely underflow */ +    decContextDefault(&dc, DEC_INIT_DECIMAL128); /* [no traps] */ +    dc.round=set->round;		     /* use supplied rounding */ +    decNumberPlus(&dw, dn, &dc);	     /* (round and check) */ +    /* [this changes -0 to 0, so enforce the sign...] */ +    dw.bits|=dn->bits&DECNEG; +    status=dc.status;			     /* save status */ +    dn=&dw;				     /* use the work number */ +    } /* maybe out of range */ + +  if (dn->bits&DECSPECIAL) {			  /* a special value */ +    if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; +     else {					  /* sNaN or qNaN */ +      if ((*dn->lsu!=0 || dn->digits>1)		  /* non-zero coefficient */ +       && (dn->digits<DECIMAL128_Pmax)) {	  /* coefficient fits */ +	decDigitsToDPD(dn, targar, 0); +	} +      if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; +       else targhi|=DECIMAL_sNaN<<24; +      } /* a NaN */ +    } /* special */ + +   else { /* is finite */ +    if (decNumberIsZero(dn)) {		     /* is a zero */ +      /* set and clamp exponent */ +      if (dn->exponent<-DECIMAL128_Bias) { +	exp=0;				     /* low clamp */ +	status|=DEC_Clamped; +	} +       else { +	exp=dn->exponent+DECIMAL128_Bias;    /* bias exponent */ +	if (exp>DECIMAL128_Ehigh) {	     /* top clamp */ +	  exp=DECIMAL128_Ehigh; +	  status|=DEC_Clamped; +	  } +	} +      comb=(exp>>9) & 0x18;		/* msd=0, exp top 2 bits .. */ +      } +     else {				/* non-zero finite number */ +      uInt msd;				/* work */ +      Int pad=0;			/* coefficient pad digits */ + +      /* the dn is known to fit, but it may need to be padded */ +      exp=(uInt)(dn->exponent+DECIMAL128_Bias);	   /* bias exponent */ +      if (exp>DECIMAL128_Ehigh) {		   /* fold-down case */ +	pad=exp-DECIMAL128_Ehigh; +	exp=DECIMAL128_Ehigh;			   /* [to maximum] */ +	status|=DEC_Clamped; +	} + +      /* [fastpath for common case is not a win, here] */ +      decDigitsToDPD(dn, targar, pad); +      /* save and clear the top digit */ +      msd=targhi>>14; +      targhi&=0x00003fff; + +      /* create the combination field */ +      if (msd>=8) comb=0x18 | ((exp>>11) & 0x06) | (msd & 0x01); +	     else comb=((exp>>9) & 0x18) | msd; +      } +    targhi|=comb<<26;		   /* add combination field .. */ +    targhi|=(exp&0xfff)<<14;	   /* .. and exponent continuation */ +    } /* finite */ + +  if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ + +  /* now write to storage; this is endian */ +  pu=(uInt *)d128->bytes;	   /* overlay */ +  if (DECLITEND) { +    pu[0]=targlo;		   /* directly store the low int */ +    pu[1]=targml;		   /* then the mid-low */ +    pu[2]=targmh;		   /* then the mid-high */ +    pu[3]=targhi;		   /* then the high int */ +    } +   else { +    pu[0]=targhi;		   /* directly store the high int */ +    pu[1]=targmh;		   /* then the mid-high */ +    pu[2]=targml;		   /* then the mid-low */ +    pu[3]=targlo;		   /* then the low int */ +    } + +  if (status!=0) decContextSetStatus(set, status); /* pass on status */ +  /* decimal128Show(d128); */ +  return d128; +  } /* decimal128FromNumber */ + +/* ------------------------------------------------------------------ */ +/* decimal128ToNumber -- convert decimal128 to decNumber	      */ +/*   d128 is the source decimal128				      */ +/*   dn is the target number, with appropriate space		      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decNumber * decimal128ToNumber(const decimal128 *d128, decNumber *dn) { +  uInt msd;			   /* coefficient MSD */ +  uInt exp;			   /* exponent top two bits */ +  uInt comb;			   /* combination field */ +  const uInt *pu;		   /* work */ +  Int  need;			   /* .. */ +  uInt sourar[4];		   /* source 128-bit */ +  #define sourhi sourar[3]	   /* name the word with the sign */ +  #define sourmh sourar[2]	   /* and the mid-high word */ +  #define sourml sourar[1]	   /* and the mod-low word */ +  #define sourlo sourar[0]	   /* and the lowest word */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d128->bytes;	   /* overlay */ +  if (DECLITEND) { +    sourlo=pu[0];		   /* directly load the low int */ +    sourml=pu[1];		   /* then the mid-low */ +    sourmh=pu[2];		   /* then the mid-high */ +    sourhi=pu[3];		   /* then the high int */ +    } +   else { +    sourhi=pu[0];		   /* directly load the high int */ +    sourmh=pu[1];		   /* then the mid-high */ +    sourml=pu[2];		   /* then the mid-low */ +    sourlo=pu[3];		   /* then the low int */ +    } + +  comb=(sourhi>>26)&0x1f;	   /* combination field */ + +  decNumberZero(dn);		   /* clean number */ +  if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ + +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) {			   /* is a special */ +    if (msd==0) { +      dn->bits|=DECINF; +      return dn;		   /* no coefficient needed */ +      } +    else if (sourhi&0x02000000) dn->bits|=DECSNAN; +    else dn->bits|=DECNAN; +    msd=0;			   /* no top digit */ +    } +   else {			   /* is a finite number */ +    dn->exponent=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ +    } + +  /* get the coefficient */ +  sourhi&=0x00003fff;		   /* clean coefficient continuation */ +  if (msd) {			   /* non-zero msd */ +    sourhi|=msd<<14;		   /* prefix to coefficient */ +    need=12;			   /* process 12 declets */ +    } +   else { /* msd=0 */ +    if (sourhi) need=11;	   /* declets to process */ +     else if (sourmh) need=10; +     else if (sourml) need=7; +     else if (sourlo) need=4; +     else return dn;		   /* easy: coefficient is 0 */ +    } /*msd=0 */ + +  decDigitsFromDPD(dn, sourar, need);	/* process declets */ +  /* decNumberShow(dn); */ +  return dn; +  } /* decimal128ToNumber */ + +/* ------------------------------------------------------------------ */ +/* to-scientific-string -- conversion to numeric string		      */ +/* to-engineering-string -- conversion to numeric string	      */ +/*								      */ +/*   decimal128ToString(d128, string);				      */ +/*   decimal128ToEngString(d128, string);			      */ +/*								      */ +/*  d128 is the decimal128 format number to convert		      */ +/*  string is the string where the result will be laid out	      */ +/*								      */ +/*  string must be at least 24 characters			      */ +/*								      */ +/*  No error is possible, and no status can be set.		      */ +/* ------------------------------------------------------------------ */ +char * decimal128ToEngString(const decimal128 *d128, char *string){ +  decNumber dn;				/* work */ +  decimal128ToNumber(d128, &dn); +  decNumberToEngString(&dn, string); +  return string; +  } /* decimal128ToEngString */ + +char * decimal128ToString(const decimal128 *d128, char *string){ +  uInt msd;			   /* coefficient MSD */ +  Int  exp;			   /* exponent top two bits or full */ +  uInt comb;			   /* combination field */ +  char *cstart;			   /* coefficient start */ +  char *c;			   /* output pointer in string */ +  const uInt *pu;		   /* work */ +  char *s, *t;			   /* .. (source, target) */ +  Int  dpd;			   /* .. */ +  Int  pre, e;			   /* .. */ +  const uByte *u;		   /* .. */ + +  uInt sourar[4];		   /* source 128-bit */ +  #define sourhi sourar[3]	   /* name the word with the sign */ +  #define sourmh sourar[2]	   /* and the mid-high word */ +  #define sourml sourar[1]	   /* and the mod-low word */ +  #define sourlo sourar[0]	   /* and the lowest word */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d128->bytes;	   /* overlay */ +  if (DECLITEND) { +    sourlo=pu[0];		   /* directly load the low int */ +    sourml=pu[1];		   /* then the mid-low */ +    sourmh=pu[2];		   /* then the mid-high */ +    sourhi=pu[3];		   /* then the high int */ +    } +   else { +    sourhi=pu[0];		   /* directly load the high int */ +    sourmh=pu[1];		   /* then the mid-high */ +    sourml=pu[2];		   /* then the mid-low */ +    sourlo=pu[3];		   /* then the low int */ +    } + +  c=string;			   /* where result will go */ +  if (((Int)sourhi)<0) *c++='-';   /* handle sign */ + +  comb=(sourhi>>26)&0x1f;	   /* combination field */ +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) { +    if (msd==0) {		   /* infinity */ +      strcpy(c,	  "Inf"); +      strcpy(c+3, "inity"); +      return string;		   /* easy */ +      } +    if (sourhi&0x02000000) *c++='s'; /* sNaN */ +    strcpy(c, "NaN");		   /* complete word */ +    c+=3;			   /* step past */ +    if (sourlo==0 && sourml==0 && sourmh==0 +     && (sourhi&0x0003ffff)==0) return string; /* zero payload */ +    /* otherwise drop through to add integer; set correct exp */ +    exp=0; msd=0;		   /* setup for following code */ +    } +   else exp=(exp<<12)+((sourhi>>14)&0xfff)-DECIMAL128_Bias; /* unbiased */ + +  /* convert 34 digits of significand to characters */ +  cstart=c;			   /* save start of coefficient */ +  if (msd) *c++='0'+(char)msd;	   /* non-zero most significant digit */ + +  /* Now decode the declets.  After extracting each one, it is */ +  /* decoded to binary and then to a 4-char sequence by table lookup; */ +  /* the 4-chars are a 1-char length (significant digits, except 000 */ +  /* has length 0).  This allows us to left-align the first declet */ +  /* with non-zero content, then remaining ones are full 3-char */ +  /* length.  We use fixed-length memcpys because variable-length */ +  /* causes a subroutine call in GCC.  (These are length 4 for speed */ +  /* and are safe because the array has an extra terminator byte.) */ +  #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4];			  \ +		   if (c!=cstart) {memcpy(c, u+1, 4); c+=3;}	  \ +		    else if (*u)  {memcpy(c, u+4-*u, 4); c+=*u;} +  dpd=(sourhi>>4)&0x3ff;		     /* declet 1 */ +  dpd2char; +  dpd=((sourhi&0xf)<<6) | (sourmh>>26);	     /* declet 2 */ +  dpd2char; +  dpd=(sourmh>>16)&0x3ff;		     /* declet 3 */ +  dpd2char; +  dpd=(sourmh>>6)&0x3ff;		     /* declet 4 */ +  dpd2char; +  dpd=((sourmh&0x3f)<<4) | (sourml>>28);     /* declet 5 */ +  dpd2char; +  dpd=(sourml>>18)&0x3ff;		     /* declet 6 */ +  dpd2char; +  dpd=(sourml>>8)&0x3ff;		     /* declet 7 */ +  dpd2char; +  dpd=((sourml&0xff)<<2) | (sourlo>>30);     /* declet 8 */ +  dpd2char; +  dpd=(sourlo>>20)&0x3ff;		     /* declet 9 */ +  dpd2char; +  dpd=(sourlo>>10)&0x3ff;		     /* declet 10 */ +  dpd2char; +  dpd=(sourlo)&0x3ff;			     /* declet 11 */ +  dpd2char; + +  if (c==cstart) *c++='0';	   /* all zeros -- make 0 */ + +  if (exp==0) {			   /* integer or NaN case -- easy */ +    *c='\0';			   /* terminate */ +    return string; +    } + +  /* non-0 exponent */ +  e=0;				   /* assume no E */ +  pre=c-cstart+exp; +  /* [here, pre-exp is the digits count (==1 for zero)] */ +  if (exp>0 || pre<-5) {	   /* need exponential form */ +    e=pre-1;			   /* calculate E value */ +    pre=1;			   /* assume one digit before '.' */ +    } /* exponential form */ + +  /* modify the coefficient, adding 0s, '.', and E+nn as needed */ +  s=c-1;			   /* source (LSD) */ +  if (pre>0) {			   /* ddd.ddd (plain), perhaps with E */ +    char *dotat=cstart+pre; +    if (dotat<c) {		   /* if embedded dot needed... */ +      t=c;				/* target */ +      for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ +      *t='.';				/* insert the dot */ +      c++;				/* length increased by one */ +      } + +    /* finally add the E-part, if needed; it will never be 0, and has */ +    /* a maximum length of 4 digits */ +    if (e!=0) { +      *c++='E';			   /* starts with E */ +      *c++='+';			   /* assume positive */ +      if (e<0) { +	*(c-1)='-';		   /* oops, need '-' */ +	e=-e;			   /* uInt, please */ +	} +      if (e<1000) {		   /* 3 (or fewer) digits case */ +	u=&BIN2CHAR[e*4];	   /* -> length byte */ +	memcpy(c, u+4-*u, 4);	   /* copy fixed 4 characters [is safe] */ +	c+=*u;			   /* bump pointer appropriately */ +	} +       else {			   /* 4-digits */ +	Int thou=((e>>3)*1049)>>17; /* e/1000 */ +	Int rem=e-(1000*thou);	    /* e%1000 */ +	*c++='0'+(char)thou; +	u=&BIN2CHAR[rem*4];	   /* -> length byte */ +	memcpy(c, u+1, 4);	   /* copy fixed 3+1 characters [is safe] */ +	c+=3;			   /* bump pointer, always 3 digits */ +	} +      } +    *c='\0';			   /* add terminator */ +    /*printf("res %s\n", string); */ +    return string; +    } /* pre>0 */ + +  /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ +  t=c+1-pre; +  *(t+1)='\0';				/* can add terminator now */ +  for (; s>=cstart; s--, t--) *t=*s;	/* shift whole coefficient right */ +  c=cstart; +  *c++='0';				/* always starts with 0. */ +  *c++='.'; +  for (; pre<0; pre++) *c++='0';	/* add any 0's after '.' */ +  /*printf("res %s\n", string); */ +  return string; +  } /* decimal128ToString */ + +/* ------------------------------------------------------------------ */ +/* to-number -- conversion from numeric string			      */ +/*								      */ +/*   decimal128FromString(result, string, set);			      */ +/*								      */ +/*  result  is the decimal128 format number which gets the result of  */ +/*	    the conversion					      */ +/*  *string is the character string which should contain a valid      */ +/*	    number (which may be a special value)		      */ +/*  set	    is the context					      */ +/*								      */ +/* The context is supplied to this routine is used for error handling */ +/* (setting of status and traps) and for the rounding mode, only.     */ +/* If an error occurs, the result will be a valid decimal128 NaN.     */ +/* ------------------------------------------------------------------ */ +decimal128 * decimal128FromString(decimal128 *result, const char *string, +				  decContext *set) { +  decContext dc;			     /* work */ +  decNumber dn;				     /* .. */ + +  decContextDefault(&dc, DEC_INIT_DECIMAL128); /* no traps, please */ +  dc.round=set->round;			       /* use supplied rounding */ + +  decNumberFromString(&dn, string, &dc);     /* will round if needed */ +  decimal128FromNumber(result, &dn, &dc); +  if (dc.status!=0) {			     /* something happened */ +    decContextSetStatus(set, dc.status);     /* .. pass it on */ +    } +  return result; +  } /* decimal128FromString */ + +/* ------------------------------------------------------------------ */ +/* decimal128IsCanonical -- test whether encoding is canonical	      */ +/*   d128 is the source decimal128				      */ +/*   returns 1 if the encoding of d128 is canonical, 0 otherwise      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uint32_t decimal128IsCanonical(const decimal128 *d128) { +  decNumber dn;				/* work */ +  decimal128 canon;			 /* .. */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL128); +  decimal128ToNumber(d128, &dn); +  decimal128FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ +  return memcmp(d128, &canon, DECIMAL128_Bytes)==0; +  } /* decimal128IsCanonical */ + +/* ------------------------------------------------------------------ */ +/* decimal128Canonical -- copy an encoding, ensuring it is canonical  */ +/*   d128 is the source decimal128				      */ +/*   result is the target (may be the same decimal128)		      */ +/*   returns result						      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decimal128 * decimal128Canonical(decimal128 *result, const decimal128 *d128) { +  decNumber dn;				/* work */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL128); +  decimal128ToNumber(d128, &dn); +  decimal128FromNumber(result, &dn, &dc);/* result will now be canonical */ +  return result; +  } /* decimal128Canonical */ + +#if DECTRACE || DECCHECK +/* Macros for accessing decimal128 fields.  These assume the argument +   is a reference (pointer) to the decimal128 structure, and the +   decimal128 is in network byte order (big-endian) */ +/* Get sign */ +#define decimal128Sign(d)	((unsigned)(d)->bytes[0]>>7) + +/* Get combination field */ +#define decimal128Comb(d)	(((d)->bytes[0] & 0x7c)>>2) + +/* Get exponent continuation [does not remove bias] */ +#define decimal128ExpCon(d)	((((d)->bytes[0] & 0x03)<<10)	      \ +			      | ((unsigned)(d)->bytes[1]<<2)	      \ +			      | ((unsigned)(d)->bytes[2]>>6)) + +/* Set sign [this assumes sign previously 0] */ +#define decimal128SetSign(d, b) {				      \ +  (d)->bytes[0]|=((unsigned)(b)<<7);} + +/* Set exponent continuation [does not apply bias] */ +/* This assumes range has been checked and exponent previously 0; */ +/* type of exponent must be unsigned */ +#define decimal128SetExpCon(d, e) {				      \ +  (d)->bytes[0]|=(uint8_t)((e)>>10);				      \ +  (d)->bytes[1] =(uint8_t)(((e)&0x3fc)>>2);			      \ +  (d)->bytes[2]|=(uint8_t)(((e)&0x03)<<6);} + +/* ------------------------------------------------------------------ */ +/* decimal128Show -- display a decimal128 in hexadecimal [debug aid]  */ +/*   d128 -- the number to show					      */ +/* ------------------------------------------------------------------ */ +/* Also shows sign/cob/expconfields extracted */ +void decimal128Show(const decimal128 *d128) { +  char buf[DECIMAL128_Bytes*2+1]; +  Int i, j=0; + +  if (DECLITEND) { +    for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d128->bytes[15-i]); +      } +    printf(" D128> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, +	   d128->bytes[15]>>7, (d128->bytes[15]>>2)&0x1f, +	   ((d128->bytes[15]&0x3)<<10)|(d128->bytes[14]<<2)| +	   (d128->bytes[13]>>6)); +    } +   else { +    for (i=0; i<DECIMAL128_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d128->bytes[i]); +      } +    printf(" D128> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, +	   decimal128Sign(d128), decimal128Comb(d128), +	   decimal128ExpCon(d128)); +    } +  } /* decimal128Show */ +#endif diff --git a/libdecnumber/dpd/decimal32.c b/libdecnumber/dpd/decimal32.c new file mode 100644 index 00000000..095ab756 --- /dev/null +++ b/libdecnumber/dpd/decimal32.c @@ -0,0 +1,489 @@ +/* Decimal 32-bit format module for the decNumber C Library. +   Copyright (C) 2005, 2007 Free Software Foundation, Inc. +   Contributed by IBM Corporation.  Author Mike Cowlishaw. + +   This file is part of GCC. + +   GCC is free software; you can redistribute it and/or modify it under +   the terms of the GNU General Public License as published by the Free +   Software Foundation; either version 2, or (at your option) any later +   version. + +   In addition to the permissions in the GNU General Public License, +   the Free Software Foundation gives you unlimited permission to link +   the compiled version of this file into combinations with other +   programs, and to distribute those combinations without any +   restriction coming from the use of this file.  (The General Public +   License restrictions do apply in other respects; for example, they +   cover modification of the file, and distribution when not linked +   into a combine executable.) + +   GCC is distributed in the hope that it will be useful, but WITHOUT ANY +   WARRANTY; without even the implied warranty of MERCHANTABILITY or +   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License +   for more details. + +   You should have received a copy of the GNU General Public License +   along with GCC; see the file COPYING.  If not, write to the Free +   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +   02110-1301, USA.  */ + +/* ------------------------------------------------------------------ */ +/* Decimal 32-bit format module					      */ +/* ------------------------------------------------------------------ */ +/* This module comprises the routines for decimal32 format numbers.   */ +/* Conversions are supplied to and from decNumber and String.	      */ +/*								      */ +/* This is used when decNumber provides operations, either for all    */ +/* operations or as a proxy between decNumber and decSingle.	      */ +/*								      */ +/* Error handling is the same as decNumber (qv.).		      */ +/* ------------------------------------------------------------------ */ +#include <string.h>	      /* [for memset/memcpy] */ +#include <stdio.h>	      /* [for printf] */ + +#include "libdecnumber/dconfig.h" +#define	 DECNUMDIGITS  7      /* make decNumbers with space for 7 */ +#include "libdecnumber/decNumber.h" +#include "libdecnumber/decNumberLocal.h" +#include "libdecnumber/dpd/decimal32.h" + +/* Utility tables and routines [in decimal64.c] */ +extern const uInt   COMBEXP[32], COMBMSD[32]; +extern const uByte  BIN2CHAR[4001]; + +extern void decDigitsToDPD(const decNumber *, uInt *, Int); +extern void decDigitsFromDPD(decNumber *, const uInt *, Int); + +#if DECTRACE || DECCHECK +void decimal32Show(const decimal32 *);		  /* for debug */ +extern void decNumberShow(const decNumber *);	  /* .. */ +#endif + +/* Useful macro */ +/* Clear a structure (e.g., a decNumber) */ +#define DEC_clear(d) memset(d, 0, sizeof(*d)) + +/* ------------------------------------------------------------------ */ +/* decimal32FromNumber -- convert decNumber to decimal32	      */ +/*								      */ +/*   ds is the target decimal32					      */ +/*   dn is the source number (assumed valid)			      */ +/*   set is the context, used only for reporting errors		      */ +/*								      */ +/* The set argument is used only for status reporting and for the     */ +/* rounding mode (used if the coefficient is more than DECIMAL32_Pmax */ +/* digits or an overflow is detected).	If the exponent is out of the */ +/* valid range then Overflow or Underflow will be raised.	      */ +/* After Underflow a subnormal result is possible.		      */ +/*								      */ +/* DEC_Clamped is set if the number has to be 'folded down' to fit,   */ +/* by reducing its exponent and multiplying the coefficient by a      */ +/* power of ten, or if the exponent on a zero had to be clamped.      */ +/* ------------------------------------------------------------------ */ +decimal32 * decimal32FromNumber(decimal32 *d32, const decNumber *dn, +			      decContext *set) { +  uInt status=0;		   /* status accumulator */ +  Int ae;			   /* adjusted exponent */ +  decNumber  dw;		   /* work */ +  decContext dc;		   /* .. */ +  uInt *pu;			   /* .. */ +  uInt comb, exp;		   /* .. */ +  uInt targ=0;			   /* target 32-bit */ + +  /* If the number has too many digits, or the exponent could be */ +  /* out of range then reduce the number under the appropriate */ +  /* constraints.  This could push the number to Infinity or zero, */ +  /* so this check and rounding must be done before generating the */ +  /* decimal32] */ +  ae=dn->exponent+dn->digits-1;		     /* [0 if special] */ +  if (dn->digits>DECIMAL32_Pmax		     /* too many digits */ +   || ae>DECIMAL32_Emax			     /* likely overflow */ +   || ae<DECIMAL32_Emin) {		     /* likely underflow */ +    decContextDefault(&dc, DEC_INIT_DECIMAL32); /* [no traps] */ +    dc.round=set->round;		     /* use supplied rounding */ +    decNumberPlus(&dw, dn, &dc);	     /* (round and check) */ +    /* [this changes -0 to 0, so enforce the sign...] */ +    dw.bits|=dn->bits&DECNEG; +    status=dc.status;			     /* save status */ +    dn=&dw;				     /* use the work number */ +    } /* maybe out of range */ + +  if (dn->bits&DECSPECIAL) {			  /* a special value */ +    if (dn->bits&DECINF) targ=DECIMAL_Inf<<24; +     else {					  /* sNaN or qNaN */ +      if ((*dn->lsu!=0 || dn->digits>1)		  /* non-zero coefficient */ +       && (dn->digits<DECIMAL32_Pmax)) {	  /* coefficient fits */ +	decDigitsToDPD(dn, &targ, 0); +	} +      if (dn->bits&DECNAN) targ|=DECIMAL_NaN<<24; +       else targ|=DECIMAL_sNaN<<24; +      } /* a NaN */ +    } /* special */ + +   else { /* is finite */ +    if (decNumberIsZero(dn)) {		     /* is a zero */ +      /* set and clamp exponent */ +      if (dn->exponent<-DECIMAL32_Bias) { +	exp=0;				     /* low clamp */ +	status|=DEC_Clamped; +	} +       else { +	exp=dn->exponent+DECIMAL32_Bias;     /* bias exponent */ +	if (exp>DECIMAL32_Ehigh) {	     /* top clamp */ +	  exp=DECIMAL32_Ehigh; +	  status|=DEC_Clamped; +	  } +	} +      comb=(exp>>3) & 0x18;		/* msd=0, exp top 2 bits .. */ +      } +     else {				/* non-zero finite number */ +      uInt msd;				/* work */ +      Int pad=0;			/* coefficient pad digits */ + +      /* the dn is known to fit, but it may need to be padded */ +      exp=(uInt)(dn->exponent+DECIMAL32_Bias);	  /* bias exponent */ +      if (exp>DECIMAL32_Ehigh) {		  /* fold-down case */ +	pad=exp-DECIMAL32_Ehigh; +	exp=DECIMAL32_Ehigh;			  /* [to maximum] */ +	status|=DEC_Clamped; +	} + +      /* fastpath common case */ +      if (DECDPUN==3 && pad==0) { +	targ=BIN2DPD[dn->lsu[0]]; +	if (dn->digits>3) targ|=(uInt)(BIN2DPD[dn->lsu[1]])<<10; +	msd=(dn->digits==7 ? dn->lsu[2] : 0); +	} +       else { /* general case */ +	decDigitsToDPD(dn, &targ, pad); +	/* save and clear the top digit */ +	msd=targ>>20; +	targ&=0x000fffff; +	} + +      /* create the combination field */ +      if (msd>=8) comb=0x18 | ((exp>>5) & 0x06) | (msd & 0x01); +	     else comb=((exp>>3) & 0x18) | msd; +      } +    targ|=comb<<26;		   /* add combination field .. */ +    targ|=(exp&0x3f)<<20;	   /* .. and exponent continuation */ +    } /* finite */ + +  if (dn->bits&DECNEG) targ|=0x80000000;  /* add sign bit */ + +  /* now write to storage; this is endian */ +  pu=(uInt *)d32->bytes;	   /* overlay */ +  *pu=targ;			   /* directly store the int */ + +  if (status!=0) decContextSetStatus(set, status); /* pass on status */ +  /* decimal32Show(d32); */ +  return d32; +  } /* decimal32FromNumber */ + +/* ------------------------------------------------------------------ */ +/* decimal32ToNumber -- convert decimal32 to decNumber		      */ +/*   d32 is the source decimal32				      */ +/*   dn is the target number, with appropriate space		      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decNumber * decimal32ToNumber(const decimal32 *d32, decNumber *dn) { +  uInt msd;			   /* coefficient MSD */ +  uInt exp;			   /* exponent top two bits */ +  uInt comb;			   /* combination field */ +  uInt sour;			   /* source 32-bit */ +  const uInt *pu;		   /* work */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d32->bytes;	   /* overlay */ +  sour=*pu;			   /* directly load the int */ + +  comb=(sour>>26)&0x1f;		   /* combination field */ + +  decNumberZero(dn);		   /* clean number */ +  if (sour&0x80000000) dn->bits=DECNEG; /* set sign if negative */ + +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) {			   /* is a special */ +    if (msd==0) { +      dn->bits|=DECINF; +      return dn;		   /* no coefficient needed */ +      } +    else if (sour&0x02000000) dn->bits|=DECSNAN; +    else dn->bits|=DECNAN; +    msd=0;			   /* no top digit */ +    } +   else {			   /* is a finite number */ +    dn->exponent=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */ +    } + +  /* get the coefficient */ +  sour&=0x000fffff;		   /* clean coefficient continuation */ +  if (msd) {			   /* non-zero msd */ +    sour|=msd<<20;		   /* prefix to coefficient */ +    decDigitsFromDPD(dn, &sour, 3); /* process 3 declets */ +    return dn; +    } +  /* msd=0 */ +  if (!sour) return dn;		   /* easy: coefficient is 0 */ +  if (sour&0x000ffc00)		   /* need 2 declets? */ +    decDigitsFromDPD(dn, &sour, 2); /* process 2 declets */ +   else +    decDigitsFromDPD(dn, &sour, 1); /* process 1 declet */ +  return dn; +  } /* decimal32ToNumber */ + +/* ------------------------------------------------------------------ */ +/* to-scientific-string -- conversion to numeric string		      */ +/* to-engineering-string -- conversion to numeric string	      */ +/*								      */ +/*   decimal32ToString(d32, string);				      */ +/*   decimal32ToEngString(d32, string);				      */ +/*								      */ +/*  d32 is the decimal32 format number to convert		      */ +/*  string is the string where the result will be laid out	      */ +/*								      */ +/*  string must be at least 24 characters			      */ +/*								      */ +/*  No error is possible, and no status can be set.		      */ +/* ------------------------------------------------------------------ */ +char * decimal32ToEngString(const decimal32 *d32, char *string){ +  decNumber dn;				/* work */ +  decimal32ToNumber(d32, &dn); +  decNumberToEngString(&dn, string); +  return string; +  } /* decimal32ToEngString */ + +char * decimal32ToString(const decimal32 *d32, char *string){ +  uInt msd;			   /* coefficient MSD */ +  Int  exp;			   /* exponent top two bits or full */ +  uInt comb;			   /* combination field */ +  char *cstart;			   /* coefficient start */ +  char *c;			   /* output pointer in string */ +  const uInt *pu;		   /* work */ +  const uByte *u;		   /* .. */ +  char *s, *t;			   /* .. (source, target) */ +  Int  dpd;			   /* .. */ +  Int  pre, e;			   /* .. */ +  uInt sour;			   /* source 32-bit */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d32->bytes;	   /* overlay */ +  sour=*pu;			   /* directly load the int */ + +  c=string;			   /* where result will go */ +  if (((Int)sour)<0) *c++='-';	   /* handle sign */ + +  comb=(sour>>26)&0x1f;		   /* combination field */ +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) { +    if (msd==0) {		   /* infinity */ +      strcpy(c,	  "Inf"); +      strcpy(c+3, "inity"); +      return string;		   /* easy */ +      } +    if (sour&0x02000000) *c++='s'; /* sNaN */ +    strcpy(c, "NaN");		   /* complete word */ +    c+=3;			   /* step past */ +    if ((sour&0x000fffff)==0) return string; /* zero payload */ +    /* otherwise drop through to add integer; set correct exp */ +    exp=0; msd=0;		   /* setup for following code */ +    } +   else exp=(exp<<6)+((sour>>20)&0x3f)-DECIMAL32_Bias; /* unbiased */ + +  /* convert 7 digits of significand to characters */ +  cstart=c;			   /* save start of coefficient */ +  if (msd) *c++='0'+(char)msd;	   /* non-zero most significant digit */ + +  /* Now decode the declets.  After extracting each one, it is */ +  /* decoded to binary and then to a 4-char sequence by table lookup; */ +  /* the 4-chars are a 1-char length (significant digits, except 000 */ +  /* has length 0).  This allows us to left-align the first declet */ +  /* with non-zero content, then remaining ones are full 3-char */ +  /* length.  We use fixed-length memcpys because variable-length */ +  /* causes a subroutine call in GCC.  (These are length 4 for speed */ +  /* and are safe because the array has an extra terminator byte.) */ +  #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4];			  \ +		   if (c!=cstart) {memcpy(c, u+1, 4); c+=3;}	  \ +		    else if (*u)  {memcpy(c, u+4-*u, 4); c+=*u;} + +  dpd=(sour>>10)&0x3ff;		   /* declet 1 */ +  dpd2char; +  dpd=(sour)&0x3ff;		   /* declet 2 */ +  dpd2char; + +  if (c==cstart) *c++='0';	   /* all zeros -- make 0 */ + +  if (exp==0) {			   /* integer or NaN case -- easy */ +    *c='\0';			   /* terminate */ +    return string; +    } + +  /* non-0 exponent */ +  e=0;				   /* assume no E */ +  pre=c-cstart+exp; +  /* [here, pre-exp is the digits count (==1 for zero)] */ +  if (exp>0 || pre<-5) {	   /* need exponential form */ +    e=pre-1;			   /* calculate E value */ +    pre=1;			   /* assume one digit before '.' */ +    } /* exponential form */ + +  /* modify the coefficient, adding 0s, '.', and E+nn as needed */ +  s=c-1;			   /* source (LSD) */ +  if (pre>0) {			   /* ddd.ddd (plain), perhaps with E */ +    char *dotat=cstart+pre; +    if (dotat<c) {		   /* if embedded dot needed... */ +      t=c;				/* target */ +      for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ +      *t='.';				/* insert the dot */ +      c++;				/* length increased by one */ +      } + +    /* finally add the E-part, if needed; it will never be 0, and has */ +    /* a maximum length of 3 digits (E-101 case) */ +    if (e!=0) { +      *c++='E';			   /* starts with E */ +      *c++='+';			   /* assume positive */ +      if (e<0) { +	*(c-1)='-';		   /* oops, need '-' */ +	e=-e;			   /* uInt, please */ +	} +      u=&BIN2CHAR[e*4];		   /* -> length byte */ +      memcpy(c, u+4-*u, 4);	   /* copy fixed 4 characters [is safe] */ +      c+=*u;			   /* bump pointer appropriately */ +      } +    *c='\0';			   /* add terminator */ +    /*printf("res %s\n", string); */ +    return string; +    } /* pre>0 */ + +  /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ +  t=c+1-pre; +  *(t+1)='\0';				/* can add terminator now */ +  for (; s>=cstart; s--, t--) *t=*s;	/* shift whole coefficient right */ +  c=cstart; +  *c++='0';				/* always starts with 0. */ +  *c++='.'; +  for (; pre<0; pre++) *c++='0';	/* add any 0's after '.' */ +  /*printf("res %s\n", string); */ +  return string; +  } /* decimal32ToString */ + +/* ------------------------------------------------------------------ */ +/* to-number -- conversion from numeric string			      */ +/*								      */ +/*   decimal32FromString(result, string, set);			      */ +/*								      */ +/*  result  is the decimal32 format number which gets the result of   */ +/*	    the conversion					      */ +/*  *string is the character string which should contain a valid      */ +/*	    number (which may be a special value)		      */ +/*  set	    is the context					      */ +/*								      */ +/* The context is supplied to this routine is used for error handling */ +/* (setting of status and traps) and for the rounding mode, only.     */ +/* If an error occurs, the result will be a valid decimal32 NaN.      */ +/* ------------------------------------------------------------------ */ +decimal32 * decimal32FromString(decimal32 *result, const char *string, +				decContext *set) { +  decContext dc;			     /* work */ +  decNumber dn;				     /* .. */ + +  decContextDefault(&dc, DEC_INIT_DECIMAL32); /* no traps, please */ +  dc.round=set->round;			      /* use supplied rounding */ + +  decNumberFromString(&dn, string, &dc);     /* will round if needed */ +  decimal32FromNumber(result, &dn, &dc); +  if (dc.status!=0) {			     /* something happened */ +    decContextSetStatus(set, dc.status);     /* .. pass it on */ +    } +  return result; +  } /* decimal32FromString */ + +/* ------------------------------------------------------------------ */ +/* decimal32IsCanonical -- test whether encoding is canonical	      */ +/*   d32 is the source decimal32				      */ +/*   returns 1 if the encoding of d32 is canonical, 0 otherwise	      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uint32_t decimal32IsCanonical(const decimal32 *d32) { +  decNumber dn;				/* work */ +  decimal32 canon;			/* .. */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL32); +  decimal32ToNumber(d32, &dn); +  decimal32FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ +  return memcmp(d32, &canon, DECIMAL32_Bytes)==0; +  } /* decimal32IsCanonical */ + +/* ------------------------------------------------------------------ */ +/* decimal32Canonical -- copy an encoding, ensuring it is canonical   */ +/*   d32 is the source decimal32				      */ +/*   result is the target (may be the same decimal32)		      */ +/*   returns result						      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decimal32 * decimal32Canonical(decimal32 *result, const decimal32 *d32) { +  decNumber dn;				/* work */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL32); +  decimal32ToNumber(d32, &dn); +  decimal32FromNumber(result, &dn, &dc);/* result will now be canonical */ +  return result; +  } /* decimal32Canonical */ + +#if DECTRACE || DECCHECK +/* Macros for accessing decimal32 fields.  These assume the argument +   is a reference (pointer) to the decimal32 structure, and the +   decimal32 is in network byte order (big-endian) */ +/* Get sign */ +#define decimal32Sign(d)       ((unsigned)(d)->bytes[0]>>7) + +/* Get combination field */ +#define decimal32Comb(d)       (((d)->bytes[0] & 0x7c)>>2) + +/* Get exponent continuation [does not remove bias] */ +#define decimal32ExpCon(d)     ((((d)->bytes[0] & 0x03)<<4)	      \ +			     | ((unsigned)(d)->bytes[1]>>4)) + +/* Set sign [this assumes sign previously 0] */ +#define decimal32SetSign(d, b) {				      \ +  (d)->bytes[0]|=((unsigned)(b)<<7);} + +/* Set exponent continuation [does not apply bias] */ +/* This assumes range has been checked and exponent previously 0; */ +/* type of exponent must be unsigned */ +#define decimal32SetExpCon(d, e) {				      \ +  (d)->bytes[0]|=(uint8_t)((e)>>4);				      \ +  (d)->bytes[1]|=(uint8_t)(((e)&0x0F)<<4);} + +/* ------------------------------------------------------------------ */ +/* decimal32Show -- display a decimal32 in hexadecimal [debug aid]    */ +/*   d32 -- the number to show					      */ +/* ------------------------------------------------------------------ */ +/* Also shows sign/cob/expconfields extracted - valid bigendian only */ +void decimal32Show(const decimal32 *d32) { +  char buf[DECIMAL32_Bytes*2+1]; +  Int i, j=0; + +  if (DECLITEND) { +    for (i=0; i<DECIMAL32_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d32->bytes[3-i]); +      } +    printf(" D32> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, +	   d32->bytes[3]>>7, (d32->bytes[3]>>2)&0x1f, +	   ((d32->bytes[3]&0x3)<<4)| (d32->bytes[2]>>4)); +    } +   else { +    for (i=0; i<DECIMAL32_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d32->bytes[i]); +      } +    printf(" D32> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, +	   decimal32Sign(d32), decimal32Comb(d32), decimal32ExpCon(d32)); +    } +  } /* decimal32Show */ +#endif diff --git a/libdecnumber/dpd/decimal64.c b/libdecnumber/dpd/decimal64.c new file mode 100644 index 00000000..8256084e --- /dev/null +++ b/libdecnumber/dpd/decimal64.c @@ -0,0 +1,850 @@ +/* Decimal 64-bit format module for the decNumber C Library. +   Copyright (C) 2005, 2007 Free Software Foundation, Inc. +   Contributed by IBM Corporation.  Author Mike Cowlishaw. + +   This file is part of GCC. + +   GCC is free software; you can redistribute it and/or modify it under +   the terms of the GNU General Public License as published by the Free +   Software Foundation; either version 2, or (at your option) any later +   version. + +   In addition to the permissions in the GNU General Public License, +   the Free Software Foundation gives you unlimited permission to link +   the compiled version of this file into combinations with other +   programs, and to distribute those combinations without any +   restriction coming from the use of this file.  (The General Public +   License restrictions do apply in other respects; for example, they +   cover modification of the file, and distribution when not linked +   into a combine executable.) + +   GCC is distributed in the hope that it will be useful, but WITHOUT ANY +   WARRANTY; without even the implied warranty of MERCHANTABILITY or +   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License +   for more details. + +   You should have received a copy of the GNU General Public License +   along with GCC; see the file COPYING.  If not, write to the Free +   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA +   02110-1301, USA.  */ + +/* ------------------------------------------------------------------ */ +/* Decimal 64-bit format module					      */ +/* ------------------------------------------------------------------ */ +/* This module comprises the routines for decimal64 format numbers.   */ +/* Conversions are supplied to and from decNumber and String.	      */ +/*								      */ +/* This is used when decNumber provides operations, either for all    */ +/* operations or as a proxy between decNumber and decSingle.	      */ +/*								      */ +/* Error handling is the same as decNumber (qv.).		      */ +/* ------------------------------------------------------------------ */ +#include <string.h>	      /* [for memset/memcpy] */ +#include <stdio.h>	      /* [for printf] */ + +#include "libdecnumber/dconfig.h" +#define	 DECNUMDIGITS 16      /* make decNumbers with space for 16 */ +#include "libdecnumber/decNumber.h" +#include "libdecnumber/decNumberLocal.h" +#include "libdecnumber/dpd/decimal64.h" + +/* Utility routines and tables [in decimal64.c]; externs for C++ */ +extern const uInt COMBEXP[32], COMBMSD[32]; +extern const uByte  BIN2CHAR[4001]; + +extern void decDigitsFromDPD(decNumber *, const uInt *, Int); +extern void decDigitsToDPD(const decNumber *, uInt *, Int); + +#if DECTRACE || DECCHECK +void decimal64Show(const decimal64 *);		  /* for debug */ +extern void decNumberShow(const decNumber *);	  /* .. */ +#endif + +/* Useful macro */ +/* Clear a structure (e.g., a decNumber) */ +#define DEC_clear(d) memset(d, 0, sizeof(*d)) + +/* define and include the tables to use for conversions */ +#define DEC_BIN2CHAR 1 +#define DEC_DPD2BIN  1 +#define DEC_BIN2DPD  1		   /* used for all sizes */ +#include "libdecnumber/decDPD.h" + +/* ------------------------------------------------------------------ */ +/* decimal64FromNumber -- convert decNumber to decimal64	      */ +/*								      */ +/*   ds is the target decimal64					      */ +/*   dn is the source number (assumed valid)			      */ +/*   set is the context, used only for reporting errors		      */ +/*								      */ +/* The set argument is used only for status reporting and for the     */ +/* rounding mode (used if the coefficient is more than DECIMAL64_Pmax */ +/* digits or an overflow is detected).	If the exponent is out of the */ +/* valid range then Overflow or Underflow will be raised.	      */ +/* After Underflow a subnormal result is possible.		      */ +/*								      */ +/* DEC_Clamped is set if the number has to be 'folded down' to fit,   */ +/* by reducing its exponent and multiplying the coefficient by a      */ +/* power of ten, or if the exponent on a zero had to be clamped.      */ +/* ------------------------------------------------------------------ */ +decimal64 * decimal64FromNumber(decimal64 *d64, const decNumber *dn, +				decContext *set) { +  uInt status=0;		   /* status accumulator */ +  Int ae;			   /* adjusted exponent */ +  decNumber  dw;		   /* work */ +  decContext dc;		   /* .. */ +  uInt *pu;			   /* .. */ +  uInt comb, exp;		   /* .. */ +  uInt targar[2]={0, 0};	   /* target 64-bit */ +  #define targhi targar[1]	   /* name the word with the sign */ +  #define targlo targar[0]	   /* and the other */ + +  /* If the number has too many digits, or the exponent could be */ +  /* out of range then reduce the number under the appropriate */ +  /* constraints.  This could push the number to Infinity or zero, */ +  /* so this check and rounding must be done before generating the */ +  /* decimal64] */ +  ae=dn->exponent+dn->digits-1;		     /* [0 if special] */ +  if (dn->digits>DECIMAL64_Pmax		     /* too many digits */ +   || ae>DECIMAL64_Emax			     /* likely overflow */ +   || ae<DECIMAL64_Emin) {		     /* likely underflow */ +    decContextDefault(&dc, DEC_INIT_DECIMAL64); /* [no traps] */ +    dc.round=set->round;		     /* use supplied rounding */ +    decNumberPlus(&dw, dn, &dc);	     /* (round and check) */ +    /* [this changes -0 to 0, so enforce the sign...] */ +    dw.bits|=dn->bits&DECNEG; +    status=dc.status;			     /* save status */ +    dn=&dw;				     /* use the work number */ +    } /* maybe out of range */ + +  if (dn->bits&DECSPECIAL) {			  /* a special value */ +    if (dn->bits&DECINF) targhi=DECIMAL_Inf<<24; +     else {					  /* sNaN or qNaN */ +      if ((*dn->lsu!=0 || dn->digits>1)		  /* non-zero coefficient */ +       && (dn->digits<DECIMAL64_Pmax)) {	  /* coefficient fits */ +	decDigitsToDPD(dn, targar, 0); +	} +      if (dn->bits&DECNAN) targhi|=DECIMAL_NaN<<24; +       else targhi|=DECIMAL_sNaN<<24; +      } /* a NaN */ +    } /* special */ + +   else { /* is finite */ +    if (decNumberIsZero(dn)) {		     /* is a zero */ +      /* set and clamp exponent */ +      if (dn->exponent<-DECIMAL64_Bias) { +	exp=0;				     /* low clamp */ +	status|=DEC_Clamped; +	} +       else { +	exp=dn->exponent+DECIMAL64_Bias;     /* bias exponent */ +	if (exp>DECIMAL64_Ehigh) {	     /* top clamp */ +	  exp=DECIMAL64_Ehigh; +	  status|=DEC_Clamped; +	  } +	} +      comb=(exp>>5) & 0x18;		/* msd=0, exp top 2 bits .. */ +      } +     else {				/* non-zero finite number */ +      uInt msd;				/* work */ +      Int pad=0;			/* coefficient pad digits */ + +      /* the dn is known to fit, but it may need to be padded */ +      exp=(uInt)(dn->exponent+DECIMAL64_Bias);	  /* bias exponent */ +      if (exp>DECIMAL64_Ehigh) {		  /* fold-down case */ +	pad=exp-DECIMAL64_Ehigh; +	exp=DECIMAL64_Ehigh;			  /* [to maximum] */ +	status|=DEC_Clamped; +	} + +      /* fastpath common case */ +      if (DECDPUN==3 && pad==0) { +	uInt dpd[6]={0,0,0,0,0,0}; +	uInt i; +	Int d=dn->digits; +	for (i=0; d>0; i++, d-=3) dpd[i]=BIN2DPD[dn->lsu[i]]; +	targlo =dpd[0]; +	targlo|=dpd[1]<<10; +	targlo|=dpd[2]<<20; +	if (dn->digits>6) { +	  targlo|=dpd[3]<<30; +	  targhi =dpd[3]>>2; +	  targhi|=dpd[4]<<8; +	  } +	msd=dpd[5];		   /* [did not really need conversion] */ +	} +       else { /* general case */ +	decDigitsToDPD(dn, targar, pad); +	/* save and clear the top digit */ +	msd=targhi>>18; +	targhi&=0x0003ffff; +	} + +      /* create the combination field */ +      if (msd>=8) comb=0x18 | ((exp>>7) & 0x06) | (msd & 0x01); +	     else comb=((exp>>5) & 0x18) | msd; +      } +    targhi|=comb<<26;		   /* add combination field .. */ +    targhi|=(exp&0xff)<<18;	   /* .. and exponent continuation */ +    } /* finite */ + +  if (dn->bits&DECNEG) targhi|=0x80000000; /* add sign bit */ + +  /* now write to storage; this is now always endian */ +  pu=(uInt *)d64->bytes;	   /* overlay */ +  if (DECLITEND) { +    pu[0]=targar[0];		   /* directly store the low int */ +    pu[1]=targar[1];		   /* then the high int */ +    } +   else { +    pu[0]=targar[1];		   /* directly store the high int */ +    pu[1]=targar[0];		   /* then the low int */ +    } + +  if (status!=0) decContextSetStatus(set, status); /* pass on status */ +  /* decimal64Show(d64); */ +  return d64; +  } /* decimal64FromNumber */ + +/* ------------------------------------------------------------------ */ +/* decimal64ToNumber -- convert decimal64 to decNumber		      */ +/*   d64 is the source decimal64				      */ +/*   dn is the target number, with appropriate space		      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decNumber * decimal64ToNumber(const decimal64 *d64, decNumber *dn) { +  uInt msd;			   /* coefficient MSD */ +  uInt exp;			   /* exponent top two bits */ +  uInt comb;			   /* combination field */ +  const uInt *pu;		   /* work */ +  Int  need;			   /* .. */ +  uInt sourar[2];		   /* source 64-bit */ +  #define sourhi sourar[1]	   /* name the word with the sign */ +  #define sourlo sourar[0]	   /* and the lower word */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d64->bytes;	   /* overlay */ +  if (DECLITEND) { +    sourlo=pu[0];		   /* directly load the low int */ +    sourhi=pu[1];		   /* then the high int */ +    } +   else { +    sourhi=pu[0];		   /* directly load the high int */ +    sourlo=pu[1];		   /* then the low int */ +    } + +  comb=(sourhi>>26)&0x1f;	   /* combination field */ + +  decNumberZero(dn);		   /* clean number */ +  if (sourhi&0x80000000) dn->bits=DECNEG; /* set sign if negative */ + +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) {			   /* is a special */ +    if (msd==0) { +      dn->bits|=DECINF; +      return dn;		   /* no coefficient needed */ +      } +    else if (sourhi&0x02000000) dn->bits|=DECSNAN; +    else dn->bits|=DECNAN; +    msd=0;			   /* no top digit */ +    } +   else {			   /* is a finite number */ +    dn->exponent=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; /* unbiased */ +    } + +  /* get the coefficient */ +  sourhi&=0x0003ffff;		   /* clean coefficient continuation */ +  if (msd) {			   /* non-zero msd */ +    sourhi|=msd<<18;		   /* prefix to coefficient */ +    need=6;			   /* process 6 declets */ +    } +   else { /* msd=0 */ +    if (!sourhi) {		   /* top word 0 */ +      if (!sourlo) return dn;	   /* easy: coefficient is 0 */ +      need=3;			   /* process at least 3 declets */ +      if (sourlo&0xc0000000) need++; /* process 4 declets */ +      /* [could reduce some more, here] */ +      } +     else {			   /* some bits in top word, msd=0 */ +      need=4;			   /* process at least 4 declets */ +      if (sourhi&0x0003ff00) need++; /* top declet!=0, process 5 */ +      } +    } /*msd=0 */ + +  decDigitsFromDPD(dn, sourar, need);	/* process declets */ +  return dn; +  } /* decimal64ToNumber */ + + +/* ------------------------------------------------------------------ */ +/* to-scientific-string -- conversion to numeric string		      */ +/* to-engineering-string -- conversion to numeric string	      */ +/*								      */ +/*   decimal64ToString(d64, string);				      */ +/*   decimal64ToEngString(d64, string);				      */ +/*								      */ +/*  d64 is the decimal64 format number to convert		      */ +/*  string is the string where the result will be laid out	      */ +/*								      */ +/*  string must be at least 24 characters			      */ +/*								      */ +/*  No error is possible, and no status can be set.		      */ +/* ------------------------------------------------------------------ */ +char * decimal64ToEngString(const decimal64 *d64, char *string){ +  decNumber dn;				/* work */ +  decimal64ToNumber(d64, &dn); +  decNumberToEngString(&dn, string); +  return string; +  } /* decimal64ToEngString */ + +char * decimal64ToString(const decimal64 *d64, char *string){ +  uInt msd;			   /* coefficient MSD */ +  Int  exp;			   /* exponent top two bits or full */ +  uInt comb;			   /* combination field */ +  char *cstart;			   /* coefficient start */ +  char *c;			   /* output pointer in string */ +  const uInt *pu;		   /* work */ +  char *s, *t;			   /* .. (source, target) */ +  Int  dpd;			   /* .. */ +  Int  pre, e;			   /* .. */ +  const uByte *u;		   /* .. */ + +  uInt sourar[2];		   /* source 64-bit */ +  #define sourhi sourar[1]	   /* name the word with the sign */ +  #define sourlo sourar[0]	   /* and the lower word */ + +  /* load source from storage; this is endian */ +  pu=(const uInt *)d64->bytes;	   /* overlay */ +  if (DECLITEND) { +    sourlo=pu[0];		   /* directly load the low int */ +    sourhi=pu[1];		   /* then the high int */ +    } +   else { +    sourhi=pu[0];		   /* directly load the high int */ +    sourlo=pu[1];		   /* then the low int */ +    } + +  c=string;			   /* where result will go */ +  if (((Int)sourhi)<0) *c++='-';   /* handle sign */ + +  comb=(sourhi>>26)&0x1f;	   /* combination field */ +  msd=COMBMSD[comb];		   /* decode the combination field */ +  exp=COMBEXP[comb];		   /* .. */ + +  if (exp==3) { +    if (msd==0) {		   /* infinity */ +      strcpy(c,	  "Inf"); +      strcpy(c+3, "inity"); +      return string;		   /* easy */ +      } +    if (sourhi&0x02000000) *c++='s'; /* sNaN */ +    strcpy(c, "NaN");		   /* complete word */ +    c+=3;			   /* step past */ +    if (sourlo==0 && (sourhi&0x0003ffff)==0) return string; /* zero payload */ +    /* otherwise drop through to add integer; set correct exp */ +    exp=0; msd=0;		   /* setup for following code */ +    } +   else exp=(exp<<8)+((sourhi>>18)&0xff)-DECIMAL64_Bias; + +  /* convert 16 digits of significand to characters */ +  cstart=c;			   /* save start of coefficient */ +  if (msd) *c++='0'+(char)msd;	   /* non-zero most significant digit */ + +  /* Now decode the declets.  After extracting each one, it is */ +  /* decoded to binary and then to a 4-char sequence by table lookup; */ +  /* the 4-chars are a 1-char length (significant digits, except 000 */ +  /* has length 0).  This allows us to left-align the first declet */ +  /* with non-zero content, then remaining ones are full 3-char */ +  /* length.  We use fixed-length memcpys because variable-length */ +  /* causes a subroutine call in GCC.  (These are length 4 for speed */ +  /* and are safe because the array has an extra terminator byte.) */ +  #define dpd2char u=&BIN2CHAR[DPD2BIN[dpd]*4];			  \ +		   if (c!=cstart) {memcpy(c, u+1, 4); c+=3;}	  \ +		    else if (*u)  {memcpy(c, u+4-*u, 4); c+=*u;} + +  dpd=(sourhi>>8)&0x3ff;		     /* declet 1 */ +  dpd2char; +  dpd=((sourhi&0xff)<<2) | (sourlo>>30);     /* declet 2 */ +  dpd2char; +  dpd=(sourlo>>20)&0x3ff;		     /* declet 3 */ +  dpd2char; +  dpd=(sourlo>>10)&0x3ff;		     /* declet 4 */ +  dpd2char; +  dpd=(sourlo)&0x3ff;			     /* declet 5 */ +  dpd2char; + +  if (c==cstart) *c++='0';	   /* all zeros -- make 0 */ + +  if (exp==0) {			   /* integer or NaN case -- easy */ +    *c='\0';			   /* terminate */ +    return string; +    } + +  /* non-0 exponent */ +  e=0;				   /* assume no E */ +  pre=c-cstart+exp; +  /* [here, pre-exp is the digits count (==1 for zero)] */ +  if (exp>0 || pre<-5) {	   /* need exponential form */ +    e=pre-1;			   /* calculate E value */ +    pre=1;			   /* assume one digit before '.' */ +    } /* exponential form */ + +  /* modify the coefficient, adding 0s, '.', and E+nn as needed */ +  s=c-1;			   /* source (LSD) */ +  if (pre>0) {			   /* ddd.ddd (plain), perhaps with E */ +    char *dotat=cstart+pre; +    if (dotat<c) {		   /* if embedded dot needed... */ +      t=c;				/* target */ +      for (; s>=dotat; s--, t--) *t=*s; /* open the gap; leave t at gap */ +      *t='.';				/* insert the dot */ +      c++;				/* length increased by one */ +      } + +    /* finally add the E-part, if needed; it will never be 0, and has */ +    /* a maximum length of 3 digits */ +    if (e!=0) { +      *c++='E';			   /* starts with E */ +      *c++='+';			   /* assume positive */ +      if (e<0) { +	*(c-1)='-';		   /* oops, need '-' */ +	e=-e;			   /* uInt, please */ +	} +      u=&BIN2CHAR[e*4];		   /* -> length byte */ +      memcpy(c, u+4-*u, 4);	   /* copy fixed 4 characters [is safe] */ +      c+=*u;			   /* bump pointer appropriately */ +      } +    *c='\0';			   /* add terminator */ +    /*printf("res %s\n", string); */ +    return string; +    } /* pre>0 */ + +  /* -5<=pre<=0: here for plain 0.ddd or 0.000ddd forms (can never have E) */ +  t=c+1-pre; +  *(t+1)='\0';				/* can add terminator now */ +  for (; s>=cstart; s--, t--) *t=*s;	/* shift whole coefficient right */ +  c=cstart; +  *c++='0';				/* always starts with 0. */ +  *c++='.'; +  for (; pre<0; pre++) *c++='0';	/* add any 0's after '.' */ +  /*printf("res %s\n", string); */ +  return string; +  } /* decimal64ToString */ + +/* ------------------------------------------------------------------ */ +/* to-number -- conversion from numeric string			      */ +/*								      */ +/*   decimal64FromString(result, string, set);			      */ +/*								      */ +/*  result  is the decimal64 format number which gets the result of   */ +/*	    the conversion					      */ +/*  *string is the character string which should contain a valid      */ +/*	    number (which may be a special value)		      */ +/*  set	    is the context					      */ +/*								      */ +/* The context is supplied to this routine is used for error handling */ +/* (setting of status and traps) and for the rounding mode, only.     */ +/* If an error occurs, the result will be a valid decimal64 NaN.      */ +/* ------------------------------------------------------------------ */ +decimal64 * decimal64FromString(decimal64 *result, const char *string, +				decContext *set) { +  decContext dc;			     /* work */ +  decNumber dn;				     /* .. */ + +  decContextDefault(&dc, DEC_INIT_DECIMAL64); /* no traps, please */ +  dc.round=set->round;			      /* use supplied rounding */ + +  decNumberFromString(&dn, string, &dc);     /* will round if needed */ + +  decimal64FromNumber(result, &dn, &dc); +  if (dc.status!=0) {			     /* something happened */ +    decContextSetStatus(set, dc.status);     /* .. pass it on */ +    } +  return result; +  } /* decimal64FromString */ + +/* ------------------------------------------------------------------ */ +/* decimal64IsCanonical -- test whether encoding is canonical	      */ +/*   d64 is the source decimal64				      */ +/*   returns 1 if the encoding of d64 is canonical, 0 otherwise	      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +uint32_t decimal64IsCanonical(const decimal64 *d64) { +  decNumber dn;				/* work */ +  decimal64 canon;			/* .. */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL64); +  decimal64ToNumber(d64, &dn); +  decimal64FromNumber(&canon, &dn, &dc);/* canon will now be canonical */ +  return memcmp(d64, &canon, DECIMAL64_Bytes)==0; +  } /* decimal64IsCanonical */ + +/* ------------------------------------------------------------------ */ +/* decimal64Canonical -- copy an encoding, ensuring it is canonical   */ +/*   d64 is the source decimal64				      */ +/*   result is the target (may be the same decimal64)		      */ +/*   returns result						      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +decimal64 * decimal64Canonical(decimal64 *result, const decimal64 *d64) { +  decNumber dn;				/* work */ +  decContext dc;			/* .. */ +  decContextDefault(&dc, DEC_INIT_DECIMAL64); +  decimal64ToNumber(d64, &dn); +  decimal64FromNumber(result, &dn, &dc);/* result will now be canonical */ +  return result; +  } /* decimal64Canonical */ + +#if DECTRACE || DECCHECK +/* Macros for accessing decimal64 fields.  These assume the +   argument is a reference (pointer) to the decimal64 structure, +   and the decimal64 is in network byte order (big-endian) */ +/* Get sign */ +#define decimal64Sign(d)       ((unsigned)(d)->bytes[0]>>7) + +/* Get combination field */ +#define decimal64Comb(d)       (((d)->bytes[0] & 0x7c)>>2) + +/* Get exponent continuation [does not remove bias] */ +#define decimal64ExpCon(d)     ((((d)->bytes[0] & 0x03)<<6)	      \ +			     | ((unsigned)(d)->bytes[1]>>2)) + +/* Set sign [this assumes sign previously 0] */ +#define decimal64SetSign(d, b) {				      \ +  (d)->bytes[0]|=((unsigned)(b)<<7);} + +/* Set exponent continuation [does not apply bias] */ +/* This assumes range has been checked and exponent previously 0; */ +/* type of exponent must be unsigned */ +#define decimal64SetExpCon(d, e) {				      \ +  (d)->bytes[0]|=(uint8_t)((e)>>6);				      \ +  (d)->bytes[1]|=(uint8_t)(((e)&0x3F)<<2);} + +/* ------------------------------------------------------------------ */ +/* decimal64Show -- display a decimal64 in hexadecimal [debug aid]    */ +/*   d64 -- the number to show					      */ +/* ------------------------------------------------------------------ */ +/* Also shows sign/cob/expconfields extracted */ +void decimal64Show(const decimal64 *d64) { +  char buf[DECIMAL64_Bytes*2+1]; +  Int i, j=0; + +  if (DECLITEND) { +    for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d64->bytes[7-i]); +      } +    printf(" D64> %s [S:%d Cb:%02x Ec:%02x] LittleEndian\n", buf, +	   d64->bytes[7]>>7, (d64->bytes[7]>>2)&0x1f, +	   ((d64->bytes[7]&0x3)<<6)| (d64->bytes[6]>>2)); +    } +   else { /* big-endian */ +    for (i=0; i<DECIMAL64_Bytes; i++, j+=2) { +      sprintf(&buf[j], "%02x", d64->bytes[i]); +      } +    printf(" D64> %s [S:%d Cb:%02x Ec:%02x] BigEndian\n", buf, +	   decimal64Sign(d64), decimal64Comb(d64), decimal64ExpCon(d64)); +    } +  } /* decimal64Show */ +#endif + +/* ================================================================== */ +/* Shared utility routines and tables				      */ +/* ================================================================== */ +/* define and include the conversion tables to use for shared code */ +#if DECDPUN==3 +  #define DEC_DPD2BIN 1 +#else +  #define DEC_DPD2BCD 1 +#endif +#include "libdecnumber/decDPD.h" + +/* The maximum number of decNumberUnits needed for a working copy of */ +/* the units array is the ceiling of digits/DECDPUN, where digits is */ +/* the maximum number of digits in any of the formats for which this */ +/* is used.  decimal128.h must not be included in this module, so, as */ +/* a very special case, that number is defined as a literal here. */ +#define DECMAX754   34 +#define DECMAXUNITS ((DECMAX754+DECDPUN-1)/DECDPUN) + +/* ------------------------------------------------------------------ */ +/* Combination field lookup tables (uInts to save measurable work)    */ +/*								      */ +/*	COMBEXP - 2-bit most-significant-bits of exponent	      */ +/*		  [11 if an Infinity or NaN]			      */ +/*	COMBMSD - 4-bit most-significant-digit			      */ +/*		  [0=Infinity, 1=NaN if COMBEXP=11]		      */ +/*								      */ +/* Both are indexed by the 5-bit combination field (0-31)	      */ +/* ------------------------------------------------------------------ */ +const uInt COMBEXP[32]={0, 0, 0, 0, 0, 0, 0, 0, +			1, 1, 1, 1, 1, 1, 1, 1, +			2, 2, 2, 2, 2, 2, 2, 2, +			0, 0, 1, 1, 2, 2, 3, 3}; +const uInt COMBMSD[32]={0, 1, 2, 3, 4, 5, 6, 7, +			0, 1, 2, 3, 4, 5, 6, 7, +			0, 1, 2, 3, 4, 5, 6, 7, +			8, 9, 8, 9, 8, 9, 0, 1}; + +/* ------------------------------------------------------------------ */ +/* decDigitsToDPD -- pack coefficient into DPD form		      */ +/*								      */ +/*   dn	  is the source number (assumed valid, max DECMAX754 digits)  */ +/*   targ is 1, 2, or 4-element uInt array, which the caller must     */ +/*	  have cleared to zeros					      */ +/*   shift is the number of 0 digits to add on the right (normally 0) */ +/*								      */ +/* The coefficient must be known small enough to fit.  The full	      */ +/* coefficient is copied, including the leading 'odd' digit.  This    */ +/* digit is retrieved and packed into the combination field by the    */ +/* caller.							      */ +/*								      */ +/* The target uInts are altered only as necessary to receive the      */ +/* digits of the decNumber.  When more than one uInt is needed, they  */ +/* are filled from left to right (that is, the uInt at offset 0 will  */ +/* end up with the least-significant digits).			      */ +/*								      */ +/* shift is used for 'fold-down' padding.			      */ +/*								      */ +/* No error is possible.					      */ +/* ------------------------------------------------------------------ */ +#if DECDPUN<=4 +/* Constant multipliers for divide-by-power-of five using reciprocal */ +/* multiply, after removing powers of 2 by shifting, and final shift */ +/* of 17 [we only need up to **4] */ +static const uInt multies[]={131073, 26215, 5243, 1049, 210}; +/* QUOT10 -- macro to return the quotient of unit u divided by 10**n */ +#define QUOT10(u, n) ((((uInt)(u)>>(n))*multies[n])>>17) +#endif +void decDigitsToDPD(const decNumber *dn, uInt *targ, Int shift) { +  Int  cut;		      /* work */ +  Int  n;		      /* output bunch counter */ +  Int  digits=dn->digits;     /* digit countdown */ +  uInt dpd;		      /* densely packed decimal value */ +  uInt bin;		      /* binary value 0-999 */ +  uInt *uout=targ;	      /* -> current output uInt */ +  uInt	uoff=0;		      /* -> current output offset [from right] */ +  const Unit *inu=dn->lsu;    /* -> current input unit */ +  Unit	uar[DECMAXUNITS];     /* working copy of units, iff shifted */ +  #if DECDPUN!=3	      /* not fast path */ +    Unit in;		      /* current unit */ +  #endif + +  if (shift!=0) {	      /* shift towards most significant required */ +    /* shift the units array to the left by pad digits and copy */ +    /* [this code is a special case of decShiftToMost, which could */ +    /* be used instead if exposed and the array were copied first] */ +    const Unit *source;			/* .. */ +    Unit  *target, *first;		/* .. */ +    uInt  next=0;			/* work */ + +    source=dn->lsu+D2U(digits)-1;	/* where msu comes from */ +    target=uar+D2U(digits)-1+D2U(shift);/* where upper part of first cut goes */ +    cut=DECDPUN-MSUDIGITS(shift);	/* where to slice */ +    if (cut==0) {			/* unit-boundary case */ +      for (; source>=dn->lsu; source--, target--) *target=*source; +      } +     else { +      first=uar+D2U(digits+shift)-1;	/* where msu will end up */ +      for (; source>=dn->lsu; source--, target--) { +	/* split the source Unit and accumulate remainder for next */ +	#if DECDPUN<=4 +	  uInt quot=QUOT10(*source, cut); +	  uInt rem=*source-quot*DECPOWERS[cut]; +	  next+=quot; +	#else +	  uInt rem=*source%DECPOWERS[cut]; +	  next+=*source/DECPOWERS[cut]; +	#endif +	if (target<=first) *target=(Unit)next; /* write to target iff valid */ +	next=rem*DECPOWERS[DECDPUN-cut];       /* save remainder for next Unit */ +	} +      } /* shift-move */ +    /* propagate remainder to one below and clear the rest */ +    for (; target>=uar; target--) { +      *target=(Unit)next; +      next=0; +      } +    digits+=shift;		   /* add count (shift) of zeros added */ +    inu=uar;			   /* use units in working array */ +    } + +  /* now densely pack the coefficient into DPD declets */ + +  #if DECDPUN!=3		   /* not fast path */ +    in=*inu;			   /* current unit */ +    cut=0;			   /* at lowest digit */ +    bin=0;			   /* [keep compiler quiet] */ +  #endif + +  for(n=0; digits>0; n++) {	   /* each output bunch */ +    #if DECDPUN==3		   /* fast path, 3-at-a-time */ +      bin=*inu;			   /* 3 digits ready for convert */ +      digits-=3;		   /* [may go negative] */ +      inu++;			   /* may need another */ + +    #else			   /* must collect digit-by-digit */ +      Unit dig;			   /* current digit */ +      Int j;			   /* digit-in-declet count */ +      for (j=0; j<3; j++) { +	#if DECDPUN<=4 +	  Unit temp=(Unit)((uInt)(in*6554)>>16); +	  dig=(Unit)(in-X10(temp)); +	  in=temp; +	#else +	  dig=in%10; +	  in=in/10; +	#endif +	if (j==0) bin=dig; +	 else if (j==1)	 bin+=X10(dig); +	 else /* j==2 */ bin+=X100(dig); +	digits--; +	if (digits==0) break;	   /* [also protects *inu below] */ +	cut++; +	if (cut==DECDPUN) {inu++; in=*inu; cut=0;} +	} +    #endif +    /* here there are 3 digits in bin, or have used all input digits */ + +    dpd=BIN2DPD[bin]; + +    /* write declet to uInt array */ +    *uout|=dpd<<uoff; +    uoff+=10; +    if (uoff<32) continue;	   /* no uInt boundary cross */ +    uout++; +    uoff-=32; +    *uout|=dpd>>(10-uoff);	   /* collect top bits */ +    } /* n declets */ +  return; +  } /* decDigitsToDPD */ + +/* ------------------------------------------------------------------ */ +/* decDigitsFromDPD -- unpack a format's coefficient		      */ +/*								      */ +/*   dn is the target number, with 7, 16, or 34-digit space.	      */ +/*   sour is a 1, 2, or 4-element uInt array containing only declets  */ +/*   declets is the number of (right-aligned) declets in sour to      */ +/*     be processed.  This may be 1 more than the obvious number in   */ +/*     a format, as any top digit is prefixed to the coefficient      */ +/*     continuation field.  It also may be as small as 1, as the      */ +/*     caller may pre-process leading zero declets.		      */ +/*								      */ +/* When doing the 'extra declet' case care is taken to avoid writing  */ +/* extra digits when there are leading zeros, as these could overflow */ +/* the units array when DECDPUN is not 3.			      */ +/*								      */ +/* The target uInts are used only as necessary to process declets     */ +/* declets into the decNumber.	When more than one uInt is needed,    */ +/* they are used from left to right (that is, the uInt at offset 0    */ +/* provides the least-significant digits).			      */ +/*								      */ +/* dn->digits is set, but not the sign or exponent.		      */ +/* No error is possible [the redundant 888 codes are allowed].	      */ +/* ------------------------------------------------------------------ */ +void decDigitsFromDPD(decNumber *dn, const uInt *sour, Int declets) { + +  uInt	dpd;			   /* collector for 10 bits */ +  Int	n;			   /* counter */ +  Unit	*uout=dn->lsu;		   /* -> current output unit */ +  Unit	*last=uout;		   /* will be unit containing msd */ +  const uInt *uin=sour;		   /* -> current input uInt */ +  uInt	uoff=0;			   /* -> current input offset [from right] */ + +  #if DECDPUN!=3 +  uInt	bcd;			   /* BCD result */ +  uInt	nibble;			   /* work */ +  Unit	out=0;			   /* accumulator */ +  Int	cut=0;			   /* power of ten in current unit */ +  #endif +  #if DECDPUN>4 +  uInt const *pow;		   /* work */ +  #endif + +  /* Expand the densely-packed integer, right to left */ +  for (n=declets-1; n>=0; n--) {   /* count down declets of 10 bits */ +    dpd=*uin>>uoff; +    uoff+=10; +    if (uoff>32) {		   /* crossed uInt boundary */ +      uin++; +      uoff-=32; +      dpd|=*uin<<(10-uoff);	   /* get waiting bits */ +      } +    dpd&=0x3ff;			   /* clear uninteresting bits */ + +  #if DECDPUN==3 +    if (dpd==0) *uout=0; +     else { +      *uout=DPD2BIN[dpd];	   /* convert 10 bits to binary 0-999 */ +      last=uout;		   /* record most significant unit */ +      } +    uout++; +    } /* n */ + +  #else /* DECDPUN!=3 */ +    if (dpd==0) {		   /* fastpath [e.g., leading zeros] */ +      /* write out three 0 digits (nibbles); out may have digit(s) */ +      cut++; +      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +      if (n==0) break;		   /* [as below, works even if MSD=0] */ +      cut++; +      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +      cut++; +      if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +      continue; +      } + +    bcd=DPD2BCD[dpd];		   /* convert 10 bits to 12 bits BCD */ + +    /* now accumulate the 3 BCD nibbles into units */ +    nibble=bcd & 0x00f; +    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); +    cut++; +    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +    bcd>>=4; + +    /* if this is the last declet and the remaining nibbles in bcd */ +    /* are 00 then process no more nibbles, because this could be */ +    /* the 'odd' MSD declet and writing any more Units would then */ +    /* overflow the unit array */ +    if (n==0 && !bcd) break; + +    nibble=bcd & 0x00f; +    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); +    cut++; +    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +    bcd>>=4; + +    nibble=bcd & 0x00f; +    if (nibble) out=(Unit)(out+nibble*DECPOWERS[cut]); +    cut++; +    if (cut==DECDPUN) {*uout=out; if (out) {last=uout; out=0;} uout++; cut=0;} +    } /* n */ +  if (cut!=0) {				/* some more left over */ +    *uout=out;				/* write out final unit */ +    if (out) last=uout;			/* and note if non-zero */ +    } +  #endif + +  /* here, last points to the most significant unit with digits; */ +  /* inspect it to get the final digits count -- this is essentially */ +  /* the same code as decGetDigits in decNumber.c */ +  dn->digits=(last-dn->lsu)*DECDPUN+1;	/* floor of digits, plus */ +					/* must be at least 1 digit */ +  #if DECDPUN>1 +  if (*last<10) return;			/* common odd digit or 0 */ +  dn->digits++;				/* must be 2 at least */ +  #if DECDPUN>2 +  if (*last<100) return;		/* 10-99 */ +  dn->digits++;				/* must be 3 at least */ +  #if DECDPUN>3 +  if (*last<1000) return;		/* 100-999 */ +  dn->digits++;				/* must be 4 at least */ +  #if DECDPUN>4 +  for (pow=&DECPOWERS[4]; *last>=*pow; pow++) dn->digits++; +  #endif +  #endif +  #endif +  #endif +  return; +  } /*decDigitsFromDPD */  | 
