seqAigCore.c 31.5 KB
Newer Older
Alan Mishchenko committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/**CFile****************************************************************

  FileName    [seqRetCore.c]

  SystemName  [ABC: Logic synthesis and verification system.]

  PackageName [Construction and manipulation of sequential AIGs.]

  Synopsis    [The core of retiming procedures.]

  Author      [Alan Mishchenko]
  
  Affiliation [UC Berkeley]

  Date        [Ver. 1.0. Started - June 20, 2005.]

  Revision    [$Id: seqRetCore.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]

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

#include "seqInt.h"

23 24 25
ABC_NAMESPACE_IMPL_START


Alan Mishchenko committed
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
////////////////////////////////////////////////////////////////////////
///                        DECLARATIONS                              ///
////////////////////////////////////////////////////////////////////////

/* 
    Retiming can be represented in three equivalent forms:
    - as a set of integer lags for each node (array of chars by node ID)
    - as a set of node numbers with lag for each, fwd and bwd (two arrays of Seq_RetStep_t_)
    - as a set of latch moves over the nodes, fwd and bwd (two arrays of node pointers Abc_Obj_t *)
*/

static void        Abc_ObjRetimeForward( Abc_Obj_t * pObj );
static int         Abc_ObjRetimeBackward( Abc_Obj_t * pObj, Abc_Ntk_t * pNtk, stmm_table * tTable, Vec_Int_t * vValues );
static void        Abc_ObjRetimeBackwardUpdateEdge( Abc_Obj_t * pObj, int Edge, stmm_table * tTable );
static void        Abc_NtkRetimeSetInitialValues( Abc_Ntk_t * pNtk, stmm_table * tTable, int * pModel );

static void        Seq_NtkImplementRetimingForward( Abc_Ntk_t * pNtk, Vec_Ptr_t * vMoves );
static int         Seq_NtkImplementRetimingBackward( Abc_Ntk_t * pNtk, Vec_Ptr_t * vMoves, int fVerbose );
static void        Abc_ObjRetimeForward( Abc_Obj_t * pObj );
static int         Abc_ObjRetimeBackward( Abc_Obj_t * pObj, Abc_Ntk_t * pNtk, stmm_table * tTable, Vec_Int_t * vValues );
static void        Abc_ObjRetimeBackwardUpdateEdge( Abc_Obj_t * pObj, int Edge, stmm_table * tTable );
static void        Abc_NtkRetimeSetInitialValues( Abc_Ntk_t * pNtk, stmm_table * tTable, int * pModel );

49 50
static Vec_Ptr_t * Abc_NtkUtilRetimingTry( Abc_Ntk_t * pNtk, int fForward );
static Vec_Ptr_t * Abc_NtkUtilRetimingGetMoves( Abc_Ntk_t * pNtk, Vec_Int_t * vSteps, int fForward );
Alan Mishchenko committed
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
static Vec_Int_t * Abc_NtkUtilRetimingSplit( Vec_Str_t * vLags, int fForward );
static void        Abc_ObjRetimeForwardTry( Abc_Obj_t * pObj, int nLatches );  
static void        Abc_ObjRetimeBackwardTry( Abc_Obj_t * pObj, int nLatches );
  

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

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

  Synopsis    [Performs performs optimal delay retiming.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Seq_NtkSeqRetimeDelay( Abc_Ntk_t * pNtk, int nMaxIters, int fInitial, int fVerbose )
{
    Abc_Seq_t * p = pNtk->pManFunc;
    int RetValue;
    if ( !fInitial )
        Seq_NtkLatchSetValues( pNtk, ABC_INIT_DC );
    // get the retiming lags
    p->nMaxIters = nMaxIters;
    if ( !Seq_AigRetimeDelayLags( pNtk, fVerbose ) )
        return;
    // implement this retiming
    RetValue = Seq_NtkImplementRetiming( pNtk, p->vLags, fVerbose );
    if ( RetValue == 0 )
        printf( "Retiming completed but initial state computation has failed.\n" );
}

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

  Synopsis    [Performs most forward retiming.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Seq_NtkSeqRetimeForward( Abc_Ntk_t * pNtk, int fInitial, int fVerbose )
{
    Vec_Ptr_t * vMoves;
    Abc_Obj_t * pNode;
    int i;
    if ( !fInitial )
        Seq_NtkLatchSetValues( pNtk, ABC_INIT_DC );
    // get the forward moves
    vMoves = Abc_NtkUtilRetimingTry( pNtk, 1 );
    // undo the forward moves
108
    Vec_PtrForEachEntryReverse( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
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
        Abc_ObjRetimeBackwardTry( pNode, 1 );
    // implement this forward retiming
    Seq_NtkImplementRetimingForward( pNtk, vMoves );
    Vec_PtrFree( vMoves ); 
}

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

  Synopsis    [Performs most backward retiming.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Seq_NtkSeqRetimeBackward( Abc_Ntk_t * pNtk, int fInitial, int fVerbose )
{
    Vec_Ptr_t * vMoves;
    Abc_Obj_t * pNode;
    int i, RetValue;
    if ( !fInitial )
        Seq_NtkLatchSetValues( pNtk, ABC_INIT_DC );
    // get the backward moves
    vMoves = Abc_NtkUtilRetimingTry( pNtk, 0 );
    // undo the backward moves
136
    Vec_PtrForEachEntryReverse( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
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
        Abc_ObjRetimeForwardTry( pNode, 1 );
    // implement this backward retiming
    RetValue = Seq_NtkImplementRetimingBackward( pNtk, vMoves, fVerbose );
    Vec_PtrFree( vMoves ); 
    if ( RetValue == 0 )
        printf( "Retiming completed but initial state computation has failed.\n" );
}




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

  Synopsis    [Implements the retiming on the sequential AIG.]

  Description [Split the retiming into forward and backward.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Seq_NtkImplementRetiming( Abc_Ntk_t * pNtk, Vec_Str_t * vLags, int fVerbose )
{
    Vec_Int_t * vSteps;
    Vec_Ptr_t * vMoves;
    int RetValue;

    // forward retiming
    vSteps = Abc_NtkUtilRetimingSplit( vLags, 1 );
    // translate each set of steps into moves
    if ( fVerbose )
    printf( "The number of forward steps  = %6d.\n", Vec_IntSize(vSteps) );
    vMoves = Abc_NtkUtilRetimingGetMoves( pNtk, vSteps, 1 );
    if ( fVerbose )
    printf( "The number of forward moves  = %6d.\n", Vec_PtrSize(vMoves) );
    // implement this retiming
    Seq_NtkImplementRetimingForward( pNtk, vMoves );
    Vec_IntFree( vSteps );
    Vec_PtrFree( vMoves );

    // backward retiming
    vSteps = Abc_NtkUtilRetimingSplit( vLags, 0 );
    // translate each set of steps into moves
    if ( fVerbose )
    printf( "The number of backward steps = %6d.\n", Vec_IntSize(vSteps) );
    vMoves = Abc_NtkUtilRetimingGetMoves( pNtk, vSteps, 0 );
    if ( fVerbose )
    printf( "The number of backward moves = %6d.\n", Vec_PtrSize(vMoves) );
    // implement this retiming
    RetValue = Seq_NtkImplementRetimingBackward( pNtk, vMoves, fVerbose );
    Vec_IntFree( vSteps );
    Vec_PtrFree( vMoves );
    return RetValue;
}

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

  Synopsis    [Implements the given retiming on the sequential AIG.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Seq_NtkImplementRetimingForward( Abc_Ntk_t * pNtk, Vec_Ptr_t * vMoves )
{
    Abc_Obj_t * pNode;
    int i;
208
    Vec_PtrForEachEntry( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
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
        Abc_ObjRetimeForward( pNode );
}

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

  Synopsis    [Retimes node forward by one latch.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ObjRetimeForward( Abc_Obj_t * pObj )  
{
    Abc_Obj_t * pFanout;
    int Init0, Init1, Init, i;
    assert( Abc_ObjFaninNum(pObj) == 2 );
    assert( Seq_ObjFaninL0(pObj) >= 1 );
    assert( Seq_ObjFaninL1(pObj) >= 1 );
    // remove the init values from the fanins
    Init0 = Seq_NodeDeleteFirst( pObj, 0 ); 
    Init1 = Seq_NodeDeleteFirst( pObj, 1 );
    assert( Init0 != ABC_INIT_NONE );
    assert( Init1 != ABC_INIT_NONE );
    // take into account the complements in the node
    if ( Abc_ObjFaninC0(pObj) )
    {
        if ( Init0 == ABC_INIT_ZERO )
            Init0 = ABC_INIT_ONE;
        else if ( Init0 == ABC_INIT_ONE )
            Init0 = ABC_INIT_ZERO;
    }
    if ( Abc_ObjFaninC1(pObj) )
    {
        if ( Init1 == ABC_INIT_ZERO )
            Init1 = ABC_INIT_ONE;
        else if ( Init1 == ABC_INIT_ONE )
            Init1 = ABC_INIT_ZERO;
    }
    // compute the value at the output of the node
    if ( Init0 == ABC_INIT_ZERO || Init1 == ABC_INIT_ZERO )
        Init = ABC_INIT_ZERO;
    else if ( Init0 == ABC_INIT_ONE && Init1 == ABC_INIT_ONE )
        Init = ABC_INIT_ONE;
    else
        Init = ABC_INIT_DC;

    // make sure the label is clean
    Abc_ObjForEachFanout( pObj, pFanout, i )
        assert( pFanout->fMarkC == 0 );
    // add the init values to the fanouts
    Abc_ObjForEachFanout( pObj, pFanout, i )
    {
        if ( pFanout->fMarkC )
            continue;
        pFanout->fMarkC = 1;
        if ( Abc_ObjFaninId0(pFanout) != Abc_ObjFaninId1(pFanout) )
            Seq_NodeInsertLast( pFanout, Abc_ObjFanoutEdgeNum(pObj, pFanout), Init );
        else
        {
            assert( Abc_ObjFanin0(pFanout) == pObj );
            Seq_NodeInsertLast( pFanout, 0, Init );
            Seq_NodeInsertLast( pFanout, 1, Init );
        }
    }
    // clean the label
    Abc_ObjForEachFanout( pObj, pFanout, i )
        pFanout->fMarkC = 0;
}


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

  Synopsis    [Implements the given retiming on the sequential AIG.]

  Description [Returns 0 of initial state computation fails.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Seq_NtkImplementRetimingBackward( Abc_Ntk_t * pNtk, Vec_Ptr_t * vMoves, int fVerbose )
{
    Seq_RetEdge_t RetEdge;
    stmm_table * tTable;
    stmm_generator * gen;
    Vec_Int_t * vValues;
    Abc_Ntk_t * pNtkProb, * pNtkMiter, * pNtkCnf;
    Abc_Obj_t * pNode, * pNodeNew;
    int * pModel, RetValue, i, clk;

    // return if the retiming is trivial
    if ( Vec_PtrSize(vMoves) == 0 )
        return 1;

    // create the network for the initial state computation
    // start the table and the array of PO values
    pNtkProb = Abc_NtkAlloc( ABC_NTK_LOGIC, ABC_FUNC_SOP, 1 );
    tTable   = stmm_init_table( stmm_numcmp, stmm_numhash );
    vValues  = Vec_IntAlloc( 100 );

    // perform the backward moves and build the network for initial state computation
    RetValue = 0;
315
    Vec_PtrForEachEntry( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
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
        RetValue |= Abc_ObjRetimeBackward( pNode, pNtkProb, tTable, vValues );

    // add the PIs corresponding to the white spots
    stmm_foreach_item( tTable, gen, (char **)&RetEdge, (char **)&pNodeNew )
        Abc_ObjAddFanin( pNodeNew, Abc_NtkCreatePi(pNtkProb) );

    // add the PI/PO names
    Abc_NtkAddDummyPiNames( pNtkProb );
    Abc_NtkAddDummyPoNames( pNtkProb );

    // make sure everything is okay with the network structure
    if ( !Abc_NtkDoCheck( pNtkProb ) )
    {
        printf( "Seq_NtkImplementRetimingBackward: The internal network check has failed.\n" );
        Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
        Abc_NtkDelete( pNtkProb );
        stmm_free_table( tTable );
        Vec_IntFree( vValues );
        return 0;
    }

    // check if conflict is found
    if ( RetValue )
    {
        printf( "Seq_NtkImplementRetimingBackward: A top level conflict is detected. DC latch values are used.\n" );
        Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
        Abc_NtkDelete( pNtkProb );
        stmm_free_table( tTable );
        Vec_IntFree( vValues );
        return 0;
    }

    // get the miter cone
    pNtkMiter = Abc_NtkCreateTarget( pNtkProb, pNtkProb->vCos, vValues );
    Abc_NtkDelete( pNtkProb );
    Vec_IntFree( vValues );

    if ( fVerbose )
    printf( "The number of ANDs in the AIG = %5d.\n", Abc_NtkNodeNum(pNtkMiter) );

    // transform the miter into a logic network for efficient CNF construction
//    pNtkCnf = Abc_Ntk_Renode( pNtkMiter, 0, 100, 1, 0, 0 );
//    Abc_NtkDelete( pNtkMiter );
    pNtkCnf = pNtkMiter;

    // solve the miter
clk = clock();
//    RetValue = Abc_NtkMiterSat_OldAndRusty( pNtkCnf, 30, 0 );
    RetValue = Abc_NtkMiterSat( pNtkCnf, (sint64)500000, (sint64)50000000, 0, 0, NULL, NULL );
if ( fVerbose )
if ( clock() - clk > 100 )
{
PRT( "SAT solving time", clock() - clk );
}
    pModel = pNtkCnf->pModel;  pNtkCnf->pModel = NULL;
    Abc_NtkDelete( pNtkCnf );

    // analyze the result
    if ( RetValue == -1 || RetValue == 1 )
    {
        Abc_NtkRetimeSetInitialValues( pNtk, tTable, NULL );
        if ( RetValue == 1 )
            printf( "Seq_NtkImplementRetimingBackward: The problem is unsatisfiable. DC latch values are used.\n" );
        else
            printf( "Seq_NtkImplementRetimingBackward: The SAT problem timed out. DC latch values are used.\n" );
        stmm_free_table( tTable );
        return 0;
    }

    // set the values of the latches
    Abc_NtkRetimeSetInitialValues( pNtk, tTable, pModel );
    stmm_free_table( tTable );
    free( pModel );
    return 1;
}

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

  Synopsis    [Retimes node backward by one latch.]

  Description [Constructs the problem for initial state computation.
  Returns 1 if the conflict is found.]
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
int Abc_ObjRetimeBackward( Abc_Obj_t * pObj, Abc_Ntk_t * pNtkNew, stmm_table * tTable, Vec_Int_t * vValues )  
{
    Abc_Obj_t * pFanout;
    Abc_InitType_t Init, Value;
    Seq_RetEdge_t RetEdge;
    Abc_Obj_t * pNodeNew, * pFanoutNew, * pBuffer;
    int i, Edge, fMet0, fMet1, fMetN;

    // make sure the node can be retimed
    assert( Seq_ObjFanoutLMin(pObj) > 0 );
    // get the fanout values
    fMet0 = fMet1 = fMetN = 0;
    Abc_ObjForEachFanout( pObj, pFanout, i )
    {
        if ( Abc_ObjFaninId0(pFanout) == pObj->Id )
        {
            Init = Seq_NodeGetInitLast( pFanout, 0 );
            if ( Init == ABC_INIT_ZERO )
                fMet0 = 1;
            else if ( Init == ABC_INIT_ONE )
                fMet1 = 1;
            else if ( Init == ABC_INIT_NONE )
                fMetN = 1;
        }
        if ( Abc_ObjFaninId1(pFanout) == pObj->Id )
        {
            Init = Seq_NodeGetInitLast( pFanout, 1 );
            if ( Init == ABC_INIT_ZERO )
                fMet0 = 1;
            else if ( Init == ABC_INIT_ONE )
                fMet1 = 1;
            else if ( Init == ABC_INIT_NONE )
                fMetN = 1;
        }
    }

    // consider the case when all fanout latches have don't-care values
    // the new values on the fanin edges will be don't-cares
    if ( !fMet0 && !fMet1 && !fMetN )
    {
        // make sure the label is clean
        Abc_ObjForEachFanout( pObj, pFanout, i )
            assert( pFanout->fMarkC == 0 );
        // update the fanout edges
        Abc_ObjForEachFanout( pObj, pFanout, i )
        {
            if ( pFanout->fMarkC )
                continue;
            pFanout->fMarkC = 1;
            if ( Abc_ObjFaninId0(pFanout) == pObj->Id )
                Seq_NodeDeleteLast( pFanout, 0 );
            if ( Abc_ObjFaninId1(pFanout) == pObj->Id )
                Seq_NodeDeleteLast( pFanout, 1 );
        }
        // clean the label
        Abc_ObjForEachFanout( pObj, pFanout, i )
            pFanout->fMarkC = 0;
        // update the fanin edges
        Abc_ObjRetimeBackwardUpdateEdge( pObj, 0, tTable );
        Abc_ObjRetimeBackwardUpdateEdge( pObj, 1, tTable );
        Seq_NodeInsertFirst( pObj, 0, ABC_INIT_DC );
        Seq_NodeInsertFirst( pObj, 1, ABC_INIT_DC );
        return 0;
    }
    // the initial values on the fanout edges contain 0, 1, or unknown
    // the new values on the fanin edges will be unknown

    // add new AND-gate to the network
    pNodeNew = Abc_NtkCreateNode( pNtkNew );
473
    pNodeNew->pData = Abc_SopCreateAnd2( (Extra_MmFlex_t *)pNtkNew->pManFunc, Abc_ObjFaninC0(pObj), Abc_ObjFaninC1(pObj) );
Alan Mishchenko committed
474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540

    // add PO fanouts if any
    if ( fMet0 )
    {
        Abc_ObjAddFanin( Abc_NtkCreatePo(pNtkNew), pNodeNew );
        Vec_IntPush( vValues, 0 );
    }
    if ( fMet1 )
    {
        Abc_ObjAddFanin( Abc_NtkCreatePo(pNtkNew), pNodeNew );
        Vec_IntPush( vValues, 1 );
    }

    // make sure the label is clean
    Abc_ObjForEachFanout( pObj, pFanout, i )
        assert( pFanout->fMarkC == 0 );
    // perform the changes
    Abc_ObjForEachFanout( pObj, pFanout, i )
    {
        if ( pFanout->fMarkC )
            continue;
        pFanout->fMarkC = 1;
        if ( Abc_ObjFaninId0(pFanout) == pObj->Id )
        {
            Edge = 0;
            Value = Seq_NodeDeleteLast( pFanout, Edge );
            if ( Value == ABC_INIT_NONE )
            {
                // value is unknown, remove it from the table
                RetEdge.iNode  = pFanout->Id;
                RetEdge.iEdge  = Edge;
                RetEdge.iLatch = Seq_ObjFaninL( pFanout, Edge ); // after edge is removed
                if ( !stmm_delete( tTable, (char **)&RetEdge, (char **)&pFanoutNew ) )
                    assert( 0 );
                // create the fanout of the AND gate
                Abc_ObjAddFanin( pFanoutNew, pNodeNew );
            }
        }
        if ( Abc_ObjFaninId1(pFanout) == pObj->Id )
        {
            Edge = 1;
            Value = Seq_NodeDeleteLast( pFanout, Edge );
            if ( Value == ABC_INIT_NONE )
            {
                // value is unknown, remove it from the table
                RetEdge.iNode  = pFanout->Id;
                RetEdge.iEdge  = Edge;
                RetEdge.iLatch = Seq_ObjFaninL( pFanout, Edge ); // after edge is removed
                if ( !stmm_delete( tTable, (char **)&RetEdge, (char **)&pFanoutNew ) )
                    assert( 0 );
                // create the fanout of the AND gate
                Abc_ObjAddFanin( pFanoutNew, pNodeNew );
            }
        }
    }
    // clean the label
    Abc_ObjForEachFanout( pObj, pFanout, i )
        pFanout->fMarkC = 0;

    // update the fanin edges
    Abc_ObjRetimeBackwardUpdateEdge( pObj, 0, tTable );
    Abc_ObjRetimeBackwardUpdateEdge( pObj, 1, tTable );
    Seq_NodeInsertFirst( pObj, 0, ABC_INIT_NONE );
    Seq_NodeInsertFirst( pObj, 1, ABC_INIT_NONE );

    // add the buffer
    pBuffer = Abc_NtkCreateNode( pNtkNew );
541
    pBuffer->pData = Abc_SopCreateBuf( (Extra_MmFlex_t *)pNtkNew->pManFunc );
Alan Mishchenko committed
542 543 544 545 546 547 548 549 550 551
    Abc_ObjAddFanin( pNodeNew, pBuffer );
    // point to it from the table
    RetEdge.iNode  = pObj->Id;
    RetEdge.iEdge  = 0;
    RetEdge.iLatch = 0;
    if ( stmm_insert( tTable, (char *)Seq_RetEdge2Int(RetEdge), (char *)pBuffer ) )
        assert( 0 );

    // add the buffer
    pBuffer = Abc_NtkCreateNode( pNtkNew );
552
    pBuffer->pData = Abc_SopCreateBuf( (Extra_MmFlex_t *)pNtkNew->pManFunc );
Alan Mishchenko committed
553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645
    Abc_ObjAddFanin( pNodeNew, pBuffer );
    // point to it from the table
    RetEdge.iNode  = pObj->Id;
    RetEdge.iEdge  = 1;
    RetEdge.iLatch = 0;
    if ( stmm_insert( tTable, (char *)Seq_RetEdge2Int(RetEdge), (char *)pBuffer ) )
        assert( 0 );

    // report conflict is found
    return fMet0 && fMet1;
}

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

  Synopsis    [Generates the printable edge label with the initial state.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ObjRetimeBackwardUpdateEdge( Abc_Obj_t * pObj, int Edge, stmm_table * tTable )
{
    Abc_Obj_t * pFanoutNew;
    Seq_RetEdge_t RetEdge;
    Abc_InitType_t Init;
    int nLatches, i;

    // get the number of latches on the edge
    nLatches = Seq_ObjFaninL( pObj, Edge );
    for ( i = nLatches - 1; i >= 0; i-- )
    {
        // get the value of this latch
        Init = Seq_NodeGetInitOne( pObj, Edge, i );
        if ( Init != ABC_INIT_NONE )
            continue;
        // get the retiming edge
        RetEdge.iNode  = pObj->Id;
        RetEdge.iEdge  = Edge;
        RetEdge.iLatch = i;
        // remove entry from table and add it with a different key
        if ( !stmm_delete( tTable, (char **)&RetEdge, (char **)&pFanoutNew ) )
            assert( 0 );
        RetEdge.iLatch++;
        if ( stmm_insert( tTable, (char *)Seq_RetEdge2Int(RetEdge), (char *)pFanoutNew ) )
            assert( 0 );
    }
}

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

  Synopsis    [Sets the initial values.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_NtkRetimeSetInitialValues( Abc_Ntk_t * pNtk, stmm_table * tTable, int * pModel )
{
    Abc_Obj_t * pNode;
    stmm_generator * gen;
    Seq_RetEdge_t RetEdge;
    Abc_InitType_t Init;
    int i;

    i = 0;
    stmm_foreach_item( tTable, gen, (char **)&RetEdge, NULL )
    {
        pNode = Abc_NtkObj( pNtk, RetEdge.iNode );
        Init = pModel? (pModel[i]? ABC_INIT_ONE : ABC_INIT_ZERO) : ABC_INIT_DC;
        Seq_NodeSetInitOne( pNode, RetEdge.iEdge, RetEdge.iLatch, Init );
        i++;
    }
}



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

  Synopsis    [Performs forward retiming of the sequential AIG.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
646
Vec_Ptr_t * Abc_NtkUtilRetimingTry( Abc_Ntk_t * pNtk, int fForward )
Alan Mishchenko committed
647 648 649 650 651 652 653 654 655 656 657 658 659 660
{
    Vec_Ptr_t * vNodes, * vMoves;
    Abc_Obj_t * pNode, * pFanout, * pFanin;
    int i, k, nLatches;
    assert( Abc_NtkIsSeq( pNtk ) );
    // assume that all nodes can be retimed
    vNodes = Vec_PtrAlloc( 100 );
    Abc_AigForEachAnd( pNtk, pNode, i )
    {
        Vec_PtrPush( vNodes, pNode );
        pNode->fMarkA = 1;
    }
    // process the nodes
    vMoves = Vec_PtrAlloc( 100 );
661
    Vec_PtrForEachEntry( Abc_Obj_t *, vNodes, pNode, i )
Alan Mishchenko committed
662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
    {
//        printf( "(%d,%d) ", Seq_ObjFaninL0(pNode), Seq_ObjFaninL0(pNode) );
        // unmark the node as processed
        pNode->fMarkA = 0;
        // get the number of latches to retime
        if ( fForward )
            nLatches = Seq_ObjFaninLMin(pNode);
        else
            nLatches = Seq_ObjFanoutLMin(pNode);
        if ( nLatches == 0 )
            continue;
        assert( nLatches > 0 );
        // retime the latches forward
        if ( fForward )
            Abc_ObjRetimeForwardTry( pNode, nLatches );
        else
            Abc_ObjRetimeBackwardTry( pNode, nLatches );
        // write the moves
        for ( k = 0; k < nLatches; k++ )
            Vec_PtrPush( vMoves, pNode );
        // schedule fanouts for updating
        if ( fForward )
        {
            Abc_ObjForEachFanout( pNode, pFanout, k )
            {
                if ( Abc_ObjFaninNum(pFanout) != 2 || pFanout->fMarkA )
                    continue;
                pFanout->fMarkA = 1;
                Vec_PtrPush( vNodes, pFanout );
            }
        }
        else
        {
            Abc_ObjForEachFanin( pNode, pFanin, k )
            {
                if ( Abc_ObjFaninNum(pFanin) != 2 || pFanin->fMarkA )
                    continue;
                pFanin->fMarkA = 1;
                Vec_PtrPush( vNodes, pFanin );
            }
        }
    }
    Vec_PtrFree( vNodes );
    // make sure the marks are clean the the retiming is final
    Abc_AigForEachAnd( pNtk, pNode, i )
    {
        assert( pNode->fMarkA == 0 );
        if ( fForward ) 
            assert( Seq_ObjFaninLMin(pNode) == 0 );
        else
            assert( Seq_ObjFanoutLMin(pNode) == 0 );
    }
    return vMoves;
}

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

  Synopsis    [Translates retiming steps into retiming moves.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
728
Vec_Ptr_t * Abc_NtkUtilRetimingGetMoves( Abc_Ntk_t * pNtk, Vec_Int_t * vSteps, int fForward )
Alan Mishchenko committed
729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
{
    Seq_RetStep_t RetStep;
    Vec_Ptr_t * vMoves;
    Abc_Obj_t * pNode;
    int i, k, iNode, nLatches, Number;
    int fChange;
    assert( Abc_NtkIsSeq( pNtk ) );

/*
    // try implementing all the moves at once
    Vec_IntForEachEntry( vSteps, Number, i )
    {
        // get the retiming step
        RetStep = Seq_Int2RetStep( Number );
        // get the node to be retimed
        pNode = Abc_NtkObj( pNtk, RetStep.iNode );
        assert( RetStep.nLatches > 0 );
        nLatches = RetStep.nLatches;

        if ( fForward )
            Abc_ObjRetimeForwardTry( pNode, nLatches );
        else
            Abc_ObjRetimeBackwardTry( pNode, nLatches );
    }
    // now look if any node has wrong number of latches
    Abc_AigForEachAnd( pNtk, pNode, i )
    {
        if ( Seq_ObjFaninL0(pNode) < 0 )
            printf( "Wrong 0node %d.\n", pNode->Id );
        if ( Seq_ObjFaninL1(pNode) < 0 )
            printf( "Wrong 1node %d.\n", pNode->Id );
    }
    // try implementing all the moves at once
    Vec_IntForEachEntry( vSteps, Number, i )
    {
        // get the retiming step
        RetStep = Seq_Int2RetStep( Number );
        // get the node to be retimed
        pNode = Abc_NtkObj( pNtk, RetStep.iNode );
        assert( RetStep.nLatches > 0 );
        nLatches = RetStep.nLatches;

        if ( !fForward )
            Abc_ObjRetimeForwardTry( pNode, nLatches );
        else
            Abc_ObjRetimeBackwardTry( pNode, nLatches );
    }
*/

    // process the nodes
    vMoves = Vec_PtrAlloc( 100 );
    while ( Vec_IntSize(vSteps) > 0 )
    {
        iNode = 0;
        fChange = 0;
        Vec_IntForEachEntry( vSteps, Number, i )
        {
            // get the retiming step
            RetStep = Seq_Int2RetStep( Number );
            // get the node to be retimed
            pNode = Abc_NtkObj( pNtk, RetStep.iNode );
            assert( RetStep.nLatches > 0 );
            // get the number of latches that can be retimed
            if ( fForward )
                nLatches = Seq_ObjFaninLMin(pNode);
            else
                nLatches = Seq_ObjFanoutLMin(pNode);
            if ( nLatches == 0 )
            {
                Vec_IntWriteEntry( vSteps, iNode++, Seq_RetStep2Int(RetStep) );
                continue;
            }
            assert( nLatches > 0 );
            fChange = 1;
            // get the number of latches to be retimed over this node
            nLatches = ABC_MIN( nLatches, (int)RetStep.nLatches );
            // retime the latches forward
            if ( fForward )
                Abc_ObjRetimeForwardTry( pNode, nLatches );
            else
                Abc_ObjRetimeBackwardTry( pNode, nLatches );
            // write the moves
            for ( k = 0; k < nLatches; k++ )
                Vec_PtrPush( vMoves, pNode );
            // subtract the retiming performed
            RetStep.nLatches -= nLatches;
            // store the node if it is not retimed completely
            if ( RetStep.nLatches > 0 )
                Vec_IntWriteEntry( vSteps, iNode++, Seq_RetStep2Int(RetStep) );
        }
        // reduce the array
        Vec_IntShrink( vSteps, iNode );
        if ( !fChange )
        {
            printf( "Warning: %d strange steps (a minor bug to be fixed later).\n", Vec_IntSize(vSteps) );
/*
            Vec_IntForEachEntry( vSteps, Number, i )
            {
                RetStep = Seq_Int2RetStep( Number );
                printf( "%d(%d) ", RetStep.iNode, RetStep.nLatches );
            }
            printf( "\n" );
*/
            break;
        }
    }
    // undo the tentative retiming
    if ( fForward )
    {
838
        Vec_PtrForEachEntryReverse( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
839 840 841 842
            Abc_ObjRetimeBackwardTry( pNode, 1 );
    }
    else
    {
843
        Vec_PtrForEachEntryReverse( Abc_Obj_t *, vMoves, pNode, i )
Alan Mishchenko committed
844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979
            Abc_ObjRetimeForwardTry( pNode, 1 );
    }
    return vMoves;
}


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

  Synopsis    [Splits retiming into forward and backward.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
Vec_Int_t * Abc_NtkUtilRetimingSplit( Vec_Str_t * vLags, int fForward )
{
    Vec_Int_t * vNodes;
    Seq_RetStep_t RetStep;
    int Value, i;
    vNodes = Vec_IntAlloc( 100 );
    Vec_StrForEachEntry( vLags, Value, i )
    {
        if ( Value < 0 && fForward )
        {
            RetStep.iNode = i;
            RetStep.nLatches = -Value;
            Vec_IntPush( vNodes, Seq_RetStep2Int(RetStep) );
        }
        else if ( Value > 0 && !fForward )
        {
            RetStep.iNode = i;
            RetStep.nLatches = Value;
            Vec_IntPush( vNodes, Seq_RetStep2Int(RetStep) );
        }
    }
    return vNodes;
}

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

  Synopsis    [Retime node forward without initial states.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ObjRetimeForwardTry( Abc_Obj_t * pObj, int nLatches )  
{
    Abc_Obj_t * pFanout;
    int i;
    // make sure it is an AND gate
    assert( Abc_ObjFaninNum(pObj) == 2 );
    // make sure it has enough latches
//    assert( Seq_ObjFaninL0(pObj) >= nLatches );
//    assert( Seq_ObjFaninL1(pObj) >= nLatches );
    // subtract these latches on the fanin side
    Seq_ObjAddFaninL0( pObj, -nLatches );
    Seq_ObjAddFaninL1( pObj, -nLatches );
    // make sure the label is clean
    Abc_ObjForEachFanout( pObj, pFanout, i )
        assert( pFanout->fMarkC == 0 );
    // add these latches on the fanout side
    Abc_ObjForEachFanout( pObj, pFanout, i )
    {
        if ( pFanout->fMarkC )
            continue;
        pFanout->fMarkC = 1;
        if ( Abc_ObjFaninId0(pFanout) != Abc_ObjFaninId1(pFanout) )
            Seq_ObjAddFanoutL( pObj, pFanout, nLatches );
        else
        {
            assert( Abc_ObjFanin0(pFanout) == pObj );
            Seq_ObjAddFaninL0( pFanout, nLatches );
            Seq_ObjAddFaninL1( pFanout, nLatches );
        }
    }
    // clean the label
    Abc_ObjForEachFanout( pObj, pFanout, i )
        pFanout->fMarkC = 0;
}

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

  Synopsis    [Retime node backward without initial states.]

  Description []
               
  SideEffects []

  SeeAlso     []

***********************************************************************/
void Abc_ObjRetimeBackwardTry( Abc_Obj_t * pObj, int nLatches )  
{
    Abc_Obj_t * pFanout;
    int i;
    // make sure it is an AND gate
    assert( Abc_ObjFaninNum(pObj) == 2 );
    // make sure the label is clean
    Abc_ObjForEachFanout( pObj, pFanout, i )
        assert( pFanout->fMarkC == 0 );
    // subtract these latches on the fanout side
    Abc_ObjForEachFanout( pObj, pFanout, i )
    {
        if ( pFanout->fMarkC )
            continue;
        pFanout->fMarkC = 1;
//        assert( Abc_ObjFanoutL(pObj, pFanout) >= nLatches );
        if ( Abc_ObjFaninId0(pFanout) != Abc_ObjFaninId1(pFanout) )
            Seq_ObjAddFanoutL( pObj, pFanout, -nLatches );
        else
        {
            assert( Abc_ObjFanin0(pFanout) == pObj );
            Seq_ObjAddFaninL0( pFanout, -nLatches );
            Seq_ObjAddFaninL1( pFanout, -nLatches );
        }
    }
    // clean the label
    Abc_ObjForEachFanout( pObj, pFanout, i )
        pFanout->fMarkC = 0;
    // add these latches on the fanin side
    Seq_ObjAddFaninL0( pObj, nLatches );
    Seq_ObjAddFaninL1( pObj, nLatches );
}

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


980 981
ABC_NAMESPACE_IMPL_END