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Diffstat (limited to 'arch/parisc/math-emu/fcnvff.c')
| -rw-r--r-- | arch/parisc/math-emu/fcnvff.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/fcnvff.c b/arch/parisc/math-emu/fcnvff.c new file mode 100644 index 00000000..76c063f7 --- /dev/null +++ b/arch/parisc/math-emu/fcnvff.c @@ -0,0 +1,309 @@ +/* + * Linux/PA-RISC Project (http://www.parisc-linux.org/) + * + * Floating-point emulation code + * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> + * + * This program 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. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +/* + * BEGIN_DESC + * + * File: + * @(#) pa/spmath/fcnvff.c $Revision: 1.1 $ + * + * Purpose: + * Single Floating-point to Double Floating-point + * Double Floating-point to Single Floating-point + * + * External Interfaces: + * dbl_to_sgl_fcnvff(srcptr,nullptr,dstptr,status) + * sgl_to_dbl_fcnvff(srcptr,nullptr,dstptr,status) + * + * Internal Interfaces: + * + * Theory: + * <<please update with a overview of the operation of this file>> + * + * END_DESC +*/ + + +#include "float.h" +#include "sgl_float.h" +#include "dbl_float.h" +#include "cnv_float.h" + +/* + * Single Floating-point to Double Floating-point + */ +/*ARGSUSED*/ +int +sgl_to_dbl_fcnvff( + sgl_floating_point *srcptr, + unsigned int *nullptr, + dbl_floating_point *dstptr, + unsigned int *status) +{ + register unsigned int src, resultp1, resultp2; + register int src_exponent; + + src = *srcptr; + src_exponent = Sgl_exponent(src); + Dbl_allp1(resultp1) = Sgl_all(src); /* set sign of result */ + /* + * Test for NaN or infinity + */ + if (src_exponent == SGL_INFINITY_EXPONENT) { + /* + * determine if NaN or infinity + */ + if (Sgl_iszero_mantissa(src)) { + /* + * is infinity; want to return double infinity + */ + Dbl_setinfinity_exponentmantissa(resultp1,resultp2); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); + } + else { + /* + * is NaN; signaling or quiet? + */ + if (Sgl_isone_signaling(src)) { + /* trap if INVALIDTRAP enabled */ + if (Is_invalidtrap_enabled()) + return(INVALIDEXCEPTION); + /* make NaN quiet */ + else { + Set_invalidflag(); + Sgl_set_quiet(src); + } + } + /* + * NaN is quiet, return as double NaN + */ + Dbl_setinfinity_exponent(resultp1); + Sgl_to_dbl_mantissa(src,resultp1,resultp2); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); + } + } + /* + * Test for zero or denormalized + */ + if (src_exponent == 0) { + /* + * determine if zero or denormalized + */ + if (Sgl_isnotzero_mantissa(src)) { + /* + * is denormalized; want to normalize + */ + Sgl_clear_signexponent(src); + Sgl_leftshiftby1(src); + Sgl_normalize(src,src_exponent); + Sgl_to_dbl_exponent(src_exponent,resultp1); + Sgl_to_dbl_mantissa(src,resultp1,resultp2); + } + else { + Dbl_setzero_exponentmantissa(resultp1,resultp2); + } + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); + } + /* + * No special cases, just complete the conversion + */ + Sgl_to_dbl_exponent(src_exponent, resultp1); + Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2); + Dbl_copytoptr(resultp1,resultp2,dstptr); + return(NOEXCEPTION); +} + +/* + * Double Floating-point to Single Floating-point + */ +/*ARGSUSED*/ +int +dbl_to_sgl_fcnvff( + dbl_floating_point *srcptr, + unsigned int *nullptr, + sgl_floating_point *dstptr, + unsigned int *status) +{ + register unsigned int srcp1, srcp2, result; + register int src_exponent, dest_exponent, dest_mantissa; + register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE; + register boolean lsb_odd = FALSE; + boolean is_tiny; + + Dbl_copyfromptr(srcptr,srcp1,srcp2); + src_exponent = Dbl_exponent(srcp1); + Sgl_all(result) = Dbl_allp1(srcp1); /* set sign of result */ + /* + * Test for NaN or infinity + */ + if (src_exponent == DBL_INFINITY_EXPONENT) { + /* + * determine if NaN or infinity + */ + if (Dbl_iszero_mantissa(srcp1,srcp2)) { + /* + * is infinity; want to return single infinity + */ + Sgl_setinfinity_exponentmantissa(result); + *dstptr = result; + return(NOEXCEPTION); + } + /* + * is NaN; signaling or quiet? + */ + if (Dbl_isone_signaling(srcp1)) { + /* trap if INVALIDTRAP enabled */ + if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); + else { + Set_invalidflag(); + /* make NaN quiet */ + Dbl_set_quiet(srcp1); + } + } + /* + * NaN is quiet, return as single NaN + */ + Sgl_setinfinity_exponent(result); + Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29); + if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result); + *dstptr = result; + return(NOEXCEPTION); + } + /* + * Generate result + */ + Dbl_to_sgl_exponent(src_exponent,dest_exponent); + if (dest_exponent > 0) { + Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit, + stickybit,lsb_odd); + } + else { + if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){ + Sgl_setzero_exponentmantissa(result); + *dstptr = result; + return(NOEXCEPTION); + } + if (Is_underflowtrap_enabled()) { + Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact, + guardbit,stickybit,lsb_odd); + } + else { + /* compute result, determine inexact info, + * and set Underflowflag if appropriate + */ + Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent, + dest_mantissa,inexact,guardbit,stickybit,lsb_odd, + is_tiny); + } + } + /* + * Now round result if not exact + */ + if (inexact) { + switch (Rounding_mode()) { + case ROUNDPLUS: + if (Sgl_iszero_sign(result)) dest_mantissa++; + break; + case ROUNDMINUS: + if (Sgl_isone_sign(result)) dest_mantissa++; + break; + case ROUNDNEAREST: + if (guardbit) { + if (stickybit || lsb_odd) dest_mantissa++; + } + } + } + Sgl_set_exponentmantissa(result,dest_mantissa); + + /* + * check for mantissa overflow after rounding + */ + if ((dest_exponent>0 || Is_underflowtrap_enabled()) && + Sgl_isone_hidden(result)) dest_exponent++; + + /* + * Test for overflow + */ + if (dest_exponent >= SGL_INFINITY_EXPONENT) { + /* trap if OVERFLOWTRAP enabled */ + if (Is_overflowtrap_enabled()) { + /* + * Check for gross overflow + */ + if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP) + return(UNIMPLEMENTEDEXCEPTION); + + /* + * Adjust bias of result + */ + Sgl_setwrapped_exponent(result,dest_exponent,ovfl); + *dstptr = result; + if (inexact) + if (Is_inexacttrap_enabled()) + return(OVERFLOWEXCEPTION|INEXACTEXCEPTION); + else Set_inexactflag(); + return(OVERFLOWEXCEPTION); + } + Set_overflowflag(); + inexact = TRUE; + /* set result to infinity or largest number */ + Sgl_setoverflow(result); + } + /* + * Test for underflow + */ + else if (dest_exponent <= 0) { + /* trap if UNDERFLOWTRAP enabled */ + if (Is_underflowtrap_enabled()) { + /* + * Check for gross underflow + */ + if (dest_exponent <= -(SGL_WRAP)) + return(UNIMPLEMENTEDEXCEPTION); + /* + * Adjust bias of result + */ + Sgl_setwrapped_exponent(result,dest_exponent,unfl); + *dstptr = result; + if (inexact) + if (Is_inexacttrap_enabled()) + return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION); + else Set_inexactflag(); + return(UNDERFLOWEXCEPTION); + } + /* + * result is denormalized or signed zero + */ + if (inexact && is_tiny) Set_underflowflag(); + + } + else Sgl_set_exponent(result,dest_exponent); + *dstptr = result; + /* + * Trap if inexact trap is enabled + */ + if (inexact) + if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); + else Set_inexactflag(); + return(NOEXCEPTION); +} |