iCE40/yosys - [no description]

about summary refs log tree commit diff stats
diff options
Diffstat (limited to 'manual/PRESENTATION_ExAdv')
0 files changed, 0 insertions, 0 deletions
id='n39' href='#n39'>39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479
/**CFile****************************************************************

  FileName    [verFormula.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Verilog parser.]

  Synopsis    [Formula parser to read Verilog assign statements.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - August 19, 2006.]

  Revision    [$Id: verFormula.c,v 1.00 2006/08/19 00:00:00 alanmi Exp $]

***********************************************************************/

#include "ver.h"

ABC_NAMESPACE_IMPL_START


////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

// the list of operation symbols to be used in expressions
#define VER_PARSE_SYM_OPEN    '('   // opening parenthesis
#define VER_PARSE_SYM_CLOSE   ')'   // closing parenthesis
#define VER_PARSE_SYM_CONST0  '0'   // constant 0
#define VER_PARSE_SYM_CONST1  '1'   // constant 1
#define VER_PARSE_SYM_NEGBEF1 '!'   // negation before the variable
#define VER_PARSE_SYM_NEGBEF2 '~'   // negation before the variable
#define VER_PARSE_SYM_AND     '&'   // logic AND
#define VER_PARSE_SYM_OR      '|'   // logic OR
#define VER_PARSE_SYM_XOR     '^'   // logic XOR
#define VER_PARSE_SYM_MUX1    '?'   // first symbol of MUX
#define VER_PARSE_SYM_MUX2    ':'   // second symbol of MUX

// the list of opcodes (also specifying operation precedence)
#define VER_PARSE_OPER_NEG     7    // negation (highest precedence)
#define VER_PARSE_OPER_AND     6    // logic AND
#define VER_PARSE_OPER_XOR     5    // logic EXOR   (a'b | ab')   
#define VER_PARSE_OPER_OR      4    // logic OR
#define VER_PARSE_OPER_EQU     3    // equvalence   (a'b'| ab )
#define VER_PARSE_OPER_MUX     2    // MUX(a,b,c)   (ab | a'c )
#define VER_PARSE_OPER_MARK    1    // OpStack token standing for an opening parenthesis

// these are values of the internal Flag
#define VER_PARSE_FLAG_START   1    // after the opening parenthesis 
#define VER_PARSE_FLAG_VAR     2    // after operation is received
#define VER_PARSE_FLAG_OPER    3    // after operation symbol is received
#define VER_PARSE_FLAG_ERROR   4    // when error is detected

static Hop_Obj_t * Ver_FormulaParserTopOper( Hop_Man_t * pMan, Vec_Ptr_t * vStackFn, int Oper );
static int         Ver_FormulaParserFindVar( char * pString, Vec_Ptr_t * vNames );

////////////////////////////////////////////////////////////////////////
///                     FUNCTION DEFINITIONS                         ///
////////////////////////////////////////////////////////////////////////

/**Function*************************************************************

  Synopsis    [Parser of the formula encountered in assign statements.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Ver_FormulaParser( char * pFormula, void * pMan, Vec_Ptr_t * vNames, Vec_Ptr_t * vStackFn, Vec_Int_t * vStackOp, char * pErrorMessage )
{
    char * pTemp;
    Hop_Obj_t * bFunc, * bTemp;
    int nParans, Flag;
    int Oper, Oper1, Oper2;
    int v;

    // clear the stacks and the names
    Vec_PtrClear( vNames );
    Vec_PtrClear( vStackFn );
    Vec_IntClear( vStackOp );

    if ( !strcmp(pFormula, "0") || !strcmp(pFormula, "1\'b0") )
        return Hop_ManConst0((Hop_Man_t *)pMan);
    if ( !strcmp(pFormula, "1") || !strcmp(pFormula, "1\'b1") )
        return Hop_ManConst1((Hop_Man_t *)pMan);

    // make sure that the number of opening and closing parentheses is the same
    nParans = 0;
    for ( pTemp = pFormula; *pTemp; pTemp++ )
        if ( *pTemp == '(' )
            nParans++;
        else if ( *pTemp == ')' )
            nParans--;
    if ( nParans != 0 )
    {
        sprintf( pErrorMessage, "Parse_FormulaParser(): Different number of opening and closing parentheses ()." );
        return NULL;
    }
 
    // add parentheses
    pTemp = pFormula + strlen(pFormula) + 2;
    *pTemp-- = 0; *pTemp = ')';
    while ( --pTemp != pFormula )
        *pTemp = *(pTemp - 1);
    *pTemp = '(';

    // perform parsing
    Flag = VER_PARSE_FLAG_START;
    for ( pTemp = pFormula; *pTemp; pTemp++ )
    {
        switch ( *pTemp )
        {
        // skip all spaces, tabs, and end-of-lines
        case ' ':
        case '\t':
        case '\r':
        case '\n':
            continue;
/*
        // treat Constant 0 as a variable
        case VER_PARSE_SYM_CONST0:
            Vec_PtrPush( vStackFn, Hop_ManConst0(pMan) );  // Cudd_Ref( Hop_ManConst0(pMan) );
            if ( Flag == VER_PARSE_FLAG_VAR )
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): No operation symbol before constant 0." );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            Flag = VER_PARSE_FLAG_VAR; 
            break;

        // the same for Constant 1
        case VER_PARSE_SYM_CONST1:
            Vec_PtrPush( vStackFn, Hop_ManConst1(pMan) );  //  Cudd_Ref( Hop_ManConst1(pMan) );
            if ( Flag == VER_PARSE_FLAG_VAR )
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): No operation symbol before constant 1." );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            Flag = VER_PARSE_FLAG_VAR; 
            break;
*/
        case VER_PARSE_SYM_NEGBEF1:
        case VER_PARSE_SYM_NEGBEF2:
            if ( Flag == VER_PARSE_FLAG_VAR )
            {// if NEGBEF follows a variable, AND is assumed
                sprintf( pErrorMessage, "Parse_FormulaParser(): Variable before negation." );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            Vec_IntPush( vStackOp, VER_PARSE_OPER_NEG );
            break;

        case VER_PARSE_SYM_AND:
        case VER_PARSE_SYM_OR:
        case VER_PARSE_SYM_XOR:
        case VER_PARSE_SYM_MUX1:
        case VER_PARSE_SYM_MUX2:
            if ( Flag != VER_PARSE_FLAG_VAR )
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): There is no variable before AND, EXOR, or OR." );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            if ( *pTemp == VER_PARSE_SYM_AND )
                Vec_IntPush( vStackOp, VER_PARSE_OPER_AND );
            else if ( *pTemp == VER_PARSE_SYM_OR )
                Vec_IntPush( vStackOp, VER_PARSE_OPER_OR );
            else if ( *pTemp == VER_PARSE_SYM_XOR )
                Vec_IntPush( vStackOp, VER_PARSE_OPER_XOR );
            else if ( *pTemp == VER_PARSE_SYM_MUX1 )
                Vec_IntPush( vStackOp, VER_PARSE_OPER_MUX );
//            else if ( *pTemp == VER_PARSE_SYM_MUX2 )
//                Vec_IntPush( vStackOp, VER_PARSE_OPER_MUX );
            Flag = VER_PARSE_FLAG_OPER; 
            break;

        case VER_PARSE_SYM_OPEN:
            if ( Flag == VER_PARSE_FLAG_VAR )
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): Variable before a parenthesis." );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            Vec_IntPush( vStackOp, VER_PARSE_OPER_MARK );
            // after an opening bracket, it feels like starting over again
            Flag = VER_PARSE_FLAG_START; 
            break;

        case VER_PARSE_SYM_CLOSE:
            if ( Vec_IntSize( vStackOp ) )
            {
                while ( 1 )
                {
                    if ( !Vec_IntSize( vStackOp ) )
                    {
                        sprintf( pErrorMessage, "Parse_FormulaParser(): There is no opening parenthesis\n" );
                        Flag = VER_PARSE_FLAG_ERROR; 
                        break;
                    }
                    Oper = Vec_IntPop( vStackOp );
                    if ( Oper == VER_PARSE_OPER_MARK )
                        break;
                    // skip the second MUX operation
//                    if ( Oper == VER_PARSE_OPER_MUX2 )
//                    {
//                        Oper = Vec_IntPop( vStackOp );
//                        assert( Oper == VER_PARSE_OPER_MUX1 );
//                    }

                    // perform the given operation
                    if ( Ver_FormulaParserTopOper( (Hop_Man_t *)pMan, vStackFn, Oper ) == NULL )
                    {
                        sprintf( pErrorMessage, "Parse_FormulaParser(): Unknown operation\n" );
                        return NULL;
                    }
                }
            }
            else
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): There is no opening parenthesis\n" );
                Flag = VER_PARSE_FLAG_ERROR; 
                break;
            }
            if ( Flag != VER_PARSE_FLAG_ERROR )
                Flag = VER_PARSE_FLAG_VAR; 
            break;


        default:
            // scan the next name
            v = Ver_FormulaParserFindVar( pTemp, vNames );
            if ( *pTemp == '\\' )
                pTemp++;
            pTemp += (int)(ABC_PTRUINT_T)Vec_PtrEntry( vNames, 2*v ) - 1;

            // assume operation AND, if vars follow one another
            if ( Flag == VER_PARSE_FLAG_VAR )
            {
                sprintf( pErrorMessage, "Parse_FormulaParser(): Incorrect state." );
                return NULL;
            }
            bTemp = Hop_IthVar( (Hop_Man_t *)pMan, v );
            Vec_PtrPush( vStackFn, bTemp ); //  Cudd_Ref( bTemp );
            Flag = VER_PARSE_FLAG_VAR; 
            break;
        }

        if ( Flag == VER_PARSE_FLAG_ERROR )
            break;      // error exit
        else if ( Flag == VER_PARSE_FLAG_START )
            continue;  //  go on parsing
        else if ( Flag == VER_PARSE_FLAG_VAR )
            while ( 1 )
            {  // check if there are negations in the OpStack     
                if ( !Vec_IntSize(vStackOp) )
                    break;
                Oper = Vec_IntPop( vStackOp );
                if ( Oper != VER_PARSE_OPER_NEG )
                {
                    Vec_IntPush( vStackOp, Oper );
                    break;
                }
                else
                {
//                      Vec_PtrPush( vStackFn, Cudd_Not(Vec_PtrPop(vStackFn)) );
                      Vec_PtrPush( vStackFn, Hop_Not((Hop_Obj_t *)Vec_PtrPop(vStackFn)) );
                }
            }
        else // if ( Flag == VER_PARSE_FLAG_OPER )
            while ( 1 )
            {  // execute all the operations in the OpStack
               // with precedence higher or equal than the last one
                Oper1 = Vec_IntPop( vStackOp ); // the last operation
                if ( !Vec_IntSize(vStackOp) ) 
                {  // if it is the only operation, push it back
                    Vec_IntPush( vStackOp, Oper1 );
                    break;
                }
                Oper2 = Vec_IntPop( vStackOp ); // the operation before the last one
                if ( Oper2 >= Oper1 && !(Oper1 == Oper2 && Oper1 == VER_PARSE_OPER_MUX) )  
                {  // if Oper2 precedence is higher or equal, execute it
                    if ( Ver_FormulaParserTopOper( (Hop_Man_t *)pMan, vStackFn, Oper2 ) == NULL )
                    {
                        sprintf( pErrorMessage, "Parse_FormulaParser(): Unknown operation\n" );
                        return NULL;
                    }
                    Vec_IntPush( vStackOp,  Oper1 );     // push the last operation back
                }
                else
                {  // if Oper2 precedence is lower, push them back and done
                    Vec_IntPush( vStackOp, Oper2 );
                    Vec_IntPush( vStackOp, Oper1 );
                    break;
                }
            }
    }

    if ( Flag != VER_PARSE_FLAG_ERROR )
    {
        if ( Vec_PtrSize(vStackFn) )
        {    
            bFunc = (Hop_Obj_t *)Vec_PtrPop(vStackFn);
            if ( !Vec_PtrSize(vStackFn) )
                if ( !Vec_IntSize(vStackOp) )
                {
//                    Cudd_Deref( bFunc );
                    return bFunc;
                }
                else
                    sprintf( pErrorMessage, "Parse_FormulaParser(): Something is left in the operation stack\n" );
            else
                sprintf( pErrorMessage, "Parse_FormulaParser(): Something is left in the function stack\n" );
        }
        else
            sprintf( pErrorMessage, "Parse_FormulaParser(): The input string is empty\n" );
    }
//    Cudd_Ref( bFunc );
//    Cudd_RecursiveDeref( dd, bFunc );
    return NULL;
}

/**Function*************************************************************

  Synopsis    [Performs the operation on the top entries in the stack.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Hop_Obj_t * Ver_FormulaParserTopOper( Hop_Man_t * pMan, Vec_Ptr_t * vStackFn, int Oper )
{
    Hop_Obj_t * bArg0, * bArg1, * bArg2, * bFunc;
    // perform the given operation
    bArg2 = (Hop_Obj_t *)Vec_PtrPop( vStackFn );
    bArg1 = (Hop_Obj_t *)Vec_PtrPop( vStackFn );
    if ( Oper == VER_PARSE_OPER_AND )
        bFunc = Hop_And( pMan, bArg1, bArg2 );
    else if ( Oper == VER_PARSE_OPER_XOR )
        bFunc = Hop_Exor( pMan, bArg1, bArg2 );
    else if ( Oper == VER_PARSE_OPER_OR )
        bFunc = Hop_Or( pMan, bArg1, bArg2 );
    else if ( Oper == VER_PARSE_OPER_EQU )
        bFunc = Hop_Not( Hop_Exor( pMan, bArg1, bArg2 ) );
    else if ( Oper == VER_PARSE_OPER_MUX )
    {
        bArg0 = (Hop_Obj_t *)Vec_PtrPop( vStackFn );
//        bFunc = Cudd_bddIte( dd, bArg0, bArg1, bArg2 );  Cudd_Ref( bFunc );
        bFunc = Hop_Mux( pMan, bArg0, bArg1, bArg2 ); 
//        Cudd_RecursiveDeref( dd, bArg0 );
//        Cudd_Deref( bFunc );
    }
    else
        return NULL;
//    Cudd_Ref( bFunc );
//    Cudd_RecursiveDeref( dd, bArg1 );
//    Cudd_RecursiveDeref( dd, bArg2 );
    Vec_PtrPush( vStackFn,  bFunc );
    return bFunc;
}

/**Function*************************************************************

  Synopsis    [Returns the index of the new variable found.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Ver_FormulaParserFindVar( char * pString, Vec_Ptr_t * vNames )
{
    char * pTemp, * pTemp2;
    int nLength, nLength2, i;
    // start the string
    pTemp = pString;
    // find the end of the string delimited by other characters
    if ( *pTemp == '\\' )
    {
        pString++;
        while ( *pTemp && *pTemp != ' ' )
            pTemp++;
    }
    else
    {
        while ( *pTemp && *pTemp != ' ' && *pTemp != '\t' && *pTemp != '\r' && *pTemp != '\n' && *pTemp != ',' && *pTemp != '}' && 
                *pTemp != VER_PARSE_SYM_OPEN && *pTemp != VER_PARSE_SYM_CLOSE && 
                *pTemp != VER_PARSE_SYM_NEGBEF1 && *pTemp != VER_PARSE_SYM_NEGBEF2 && 
                *pTemp != VER_PARSE_SYM_AND && *pTemp != VER_PARSE_SYM_OR && *pTemp != VER_PARSE_SYM_XOR && 
                *pTemp != VER_PARSE_SYM_MUX1 && *pTemp != VER_PARSE_SYM_MUX2 )
                pTemp++;
    }
    // look for this string in the array
    nLength = pTemp - pString;
    for ( i = 0; i < Vec_PtrSize(vNames)/2; i++ )
    {
        nLength2 = (int)(ABC_PTRUINT_T)Vec_PtrEntry( vNames, 2*i + 0 );
        if ( nLength2 != nLength )
            continue;
        pTemp2   = (char *)Vec_PtrEntry( vNames, 2*i + 1 );
        if ( strncmp( pString, pTemp2, nLength ) )
            continue;
        return i;
    }
    // could not find - add and return the number
    Vec_PtrPush( vNames, (void *)(ABC_PTRUINT_T)nLength );
    Vec_PtrPush( vNames, pString );
    return i;
}

/**Function*************************************************************

  Synopsis    [Returns the AIG representation of the reduction formula.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void * Ver_FormulaReduction( char * pFormula, void * pMan, Vec_Ptr_t * vNames, char * pErrorMessage )
{
    Hop_Obj_t * pRes = NULL;
    int v, fCompl;
    char Symbol;

    // get the operation
    Symbol = *pFormula++;
    fCompl = ( Symbol == '~' );
    if ( fCompl )
        Symbol = *pFormula++;
    // check the operation
    if ( Symbol != '&' && Symbol != '|' && Symbol != '^' )
    {
        sprintf( pErrorMessage, "Ver_FormulaReduction(): Unknown operation (%c)\n", Symbol );
        return NULL;
    }
    // skip the brace
    while ( *pFormula++ != '{' );
    // parse the names
    Vec_PtrClear( vNames );
    while ( *pFormula != '}' )
    {
        v = Ver_FormulaParserFindVar( pFormula, vNames );
        pFormula += (int)(ABC_PTRUINT_T)Vec_PtrEntry( vNames, 2*v );
        while ( *pFormula == ' ' || *pFormula == ',' )
            pFormula++;
    }
    // compute the function
    if ( Symbol == '&' )
        pRes = Hop_CreateAnd( (Hop_Man_t *)pMan, Vec_PtrSize(vNames)/2 );
    else if ( Symbol == '|' )
        pRes = Hop_CreateOr( (Hop_Man_t *)pMan, Vec_PtrSize(vNames)/2 );
    else if ( Symbol == '^' )
        pRes = Hop_CreateExor( (Hop_Man_t *)pMan, Vec_PtrSize(vNames)/2 );
    return Hop_NotCond( pRes, fCompl );
}

////////////////////////////////////////////////////////////////////////
///                       END OF FILE                                ///
////////////////////////////////////////////////////////////////////////


ABC_NAMESPACE_IMPL_END

context:
space:
mode: