/**CFile****************************************************************
FileName [cgtCore.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Clock gating package.]
Synopsis []
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: cgtCore.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "cgtInt.h"
#include "misc/bar/bar.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [This procedure sets default parameters.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Cgt_SetDefaultParams( Cgt_Par_t * p )
{
memset( p, 0, sizeof(Cgt_Par_t) );
p->nLevelMax = 25; // the max number of levels to look for clock-gates
p->nCandMax = 1000; // the max number of candidates at each node
p->nOdcMax = 0; // the max number of ODC levels to consider
p->nConfMax = 10; // the max number of conflicts at a node
p->nVarsMin = 1000; // the min number of vars to recycle the SAT solver
p->nFlopsMin = 10; // the min number of flops to recycle the SAT solver
p->fAreaOnly = 0; // derive clock-gating to minimize area
p->fVerbose = 0; // verbosity flag
}
/**Function*************************************************************
Synopsis [Returns 1 if simulation does not filter out this candidate.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Cgt_SimulationFilter( Cgt_Man_t * p, Aig_Obj_t * pCandPart, Aig_Obj_t * pMiterPart )
{
unsigned * pInfoCand, * pInfoMiter;
int w, nWords = Abc_BitWordNum( p->nPatts );
pInfoCand = (unsigned *)Vec_PtrEntry( p->vPatts, Aig_ObjId(Aig_Regular(pCandPart)) );
pInfoMiter = (unsigned *)Vec_PtrEntry( p->vPatts, Aig_ObjId(pMiterPart) );
// C => !M -- true is the same as C & M -- false
if ( !Aig_IsComplement(pCandPart) )
{
for ( w = 0; w < nWords; w++ )
if ( pInfoCand[w] & pInfoMiter[w] )
return 0;
}
else
{
for ( w = 0; w < nWords; w++ )
if ( ~pInfoCand[w] & pInfoMiter[w] )
return 0;
}
return 1;
}
/**Function*************************************************************
Synopsis [Saves one simulation pattern.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Cgt_SimulationRecord( Cgt_Man_t * p )
{
Aig_Obj_t * pObj;
int i;
Aig_ManForEachObj( p->pPart, pObj, i )
if ( sat_solver_var_value( p->pSat, p->pCnf->pVarNums[i] ) )
Abc_InfoSetBit( (unsigned *)Vec_PtrEntry(p->vPatts, i), p->nPatts );
p->nPatts++;
if ( p->nPatts == 32 * p->nPattWords )
{
Vec_PtrReallocSimInfo( p->vPatts );
Vec_PtrCleanSimInfo( p->vPatts, p->nPattWords, 2 * p->nPattWords );
p->nPattWords *= 2;
}
}
/**Function*************************************************************
Synopsis [Performs clock-gating for the AIG.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Cgt_ClockGatingRangeCheck( Cgt_Man_t * p, int iStart, int nOutputs )
{
Vec_Ptr_t * vNodes = p->vFanout;
Aig_Obj_t * pMiter, * pCand, * pMiterFrame, * pCandFrame, * pMiterPart, * pCandPart;
int i, k, RetValue, nCalls;
assert( Vec_VecSize(p->vGatesAll) == Aig_ManCoNum(p->pFrame) );
// go through all the registers inputs of this range
for ( i = iStart; i < iStart + nOutputs; i++ )
{
nCalls = p->nCalls;
pMiter = Saig_ManLi( p->pAig, i );
Cgt_ManDetectCandidates( p->pAig, p->vUseful, Aig_ObjFanin0(pMiter), p->pPars->nLevelMax, vNodes );
// go through the candidates of this PO
Vec_PtrForEachEntry( Aig_Obj_t *, vNodes, pCand, k )
{
// get the corresponding nodes from the frames
pCandFrame = (Aig_Obj_t *)pCand->pData;
pMiterFrame = (Aig_Obj_t *)pMiter->pData;
// get the corresponding nodes from the part
pCandPart = (Aig_Obj_t *)pCandFrame->pData;
pMiterPart = (Aig_Obj_t *)pMiterFrame->pData;
// try direct polarity
if ( Cgt_SimulationFilter( p, pCandPart, pMiterPart ) )
{
RetValue = Cgt_CheckImplication( p, pCandPart, pMiterPart );
if ( RetValue == 1 )
{
Vec_VecPush( p->vGatesAll, i, pCand );
continue;
}
if ( RetValue == 0 )
Cgt_SimulationRecord( p );
}
else
p->nCallsFiltered++;
// try reverse polarity
if ( Cgt_SimulationFilter( p, Aig_Not(pCandPart), pMiterPart ) )
{
RetValue = Cgt_CheckImplication( p, Aig_Not(pCandPart), pMiterPart );
if ( RetValue == 1 )
{
Vec_VecPush( p->vGatesAll, i, Aig_Not(pCand) );
continue;
}
if ( RetValue == 0 )
Cgt_SimulationRecord( p );
}
else
p->nCallsFiltered++;
}
if ( p->pPars->fVerbose )
{
// printf( "Flop %3d : Cand = %4d. Gate = %4d. SAT calls = %3d.\n",
// i, Vec_PtrSize(vNodes), Vec_PtrSize(Vec_VecEntry(p->vGatesAll, i)), p->nCalls-nCalls );
}
}
}
/**Function*************************************************************
Synopsis [Performs clock-gating for the AIG.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Cgt_ClockGatingRange( Cgt_Man_t * p, int iStart )
{
int nOutputs, iStop;
abctime clk, clkTotal = Abc_Clock();
int nCallsUnsat = p->nCallsUnsat;
int nCallsSat = p->nCallsSat;
int nCallsUndec = p->nCallsUndec;
int nCallsFiltered = p->nCallsFiltered;
clk = Abc_Clock();
p->pPart = Cgt_ManDupPartition( p->pFrame, p->pPars->nVarsMin, p->pPars->nFlopsMin, iStart, p->pCare, p->vSuppsInv, &nOutputs );
p->pCnf = Cnf_DeriveSimple( p->pPart, nOutputs );
p->pSat = (sat_solver *)Cnf_DataWriteIntoSolver( p->pCnf, 1, 0 );
sat_solver_compress( p->pSat );
p->vPatts = Vec_PtrAllocSimInfo( Aig_ManObjNumMax(p->pPart), p->nPattWords );
Vec_PtrCleanSimInfo( p->vPatts, 0, p->nPattWords );
p->timePrepare += Abc_Clock() - clk;
Cgt_ClockGatingRangeCheck( p, iStart, nOutputs );
iStop = iStart + nOutputs;
if ( p->pPars->fVeryVerbose )
{
printf( "%5d : D =%4d. C =%5d. Var =%6d. Pr =%5d. Cex =%5d. F =%4d. Saved =%6d. ",
iStart, iStop-iStart, Aig_ManCoNum(p->pPart)-nOutputs, p->pSat->size,
p->nCallsUnsat-nCallsUnsat,
p->nCallsSat -nCallsSat,
p->nCallsUndec-nCallsUndec,
p->nCallsFiltered-nCallsFiltered );
ABC_PRT( "Time", Abc_Clock() - clkTotal );
}
Cgt_ManClean( p );
p->nRecycles++;
return iStop;
}
/**Function*************************************************************
Synopsis [Performs clock-gating for the AIG.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Vec_t * Cgt_ClockGatingCandidates( Aig_Man_t * pAig, Aig_Man_t * pCare, Cgt_Par_t * pPars, Vec_Int_t * vUseful )
{
Bar_Progress_t * pProgress = NULL;
Cgt_Par_t Pars;
Cgt_Man_t * p;
Vec_Vec_t * vGatesAll;
int iStart;
abctime clk = Abc_Clock(), clkTotal = Abc_Clock();
// reset random numbers
Aig_ManRandom( 1 );
if ( pPars == NULL )
Cgt_SetDefaultParams( pPars = &Pars );
p = Cgt_ManCreate( pAig, pCare, pPars );
p->vUseful = vUseful;
p->pFrame = Cgt_ManDeriveAigForGating( p );
p->timeAig += Abc_Clock() - clk;
assert( Aig_ManCoNum(p->pFrame) == Saig_ManRegNum(p->pAig) );
pProgress = Bar_ProgressStart( stdout, Aig_ManCoNum(p->pFrame) );
for ( iStart = 0; iStart < Aig_ManCoNum(p->pFrame); )
{
Bar_ProgressUpdate( pProgress, iStart, NULL );
iStart = Cgt_ClockGatingRange( p, iStart );
}
Bar_ProgressStop( pProgress );
vGatesAll = p->vGatesAll;
p->vGatesAll = NULL;
p->timeTotal = Abc_Clock() - clkTotal;
Cgt_ManStop( p );
return vGatesAll;
}
/**Function*************************************************************
Synopsis [Performs clock-gating for the AIG.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Vec_t * Cgt_ClockGatingInt( Aig_Man_t * pAig, Aig_Man_t * pCare, Cgt_Par_t * pPars, Vec_Int_t * vUseful )
{
Vec_Vec_t * vGatesAll, * vGates;
vGatesAll = Cgt_ClockGatingCandidates( pAig, pCare, pPars, vUseful );
if ( pPars->fAreaOnly )
vGates = Cgt_ManDecideArea( pAig, vGatesAll, pPars->nOdcMax, pPars->fVerbose );
else
vGates = Cgt_ManDecideSimple( pAig, vGatesAll, pPars->nOdcMax, pPars->fVerbose );
Vec_VecFree( vGatesAll );
return vGates;
}
Aig_Man_t * Cgt_ClockGating( Aig_Man_t * pAig, Aig_Man_t * pCare, Cgt_Par_t * pPars )
{
Aig_Man_t * pGated;
Vec_Vec_t * vGates = Cgt_ClockGatingInt( pAig, pCare, pPars, NULL );
int nNodesUsed;
if ( pPars->fVerbose )
{
// printf( "Before CG: " );
// Aig_ManPrintStats( pAig );
}
pGated = Cgt_ManDeriveGatedAig( pAig, vGates, pPars->fAreaOnly, &nNodesUsed );
if ( pPars->fVerbose )
{
// printf( "After CG: " );
// Aig_ManPrintStats( pGated );
printf( "Nodes: Before CG = %6d. After CG = %6d. (%6.2f %%). Total after CG = %6d.\n",
Aig_ManNodeNum(pAig), nNodesUsed,
100.0*nNodesUsed/Aig_ManNodeNum(pAig),
Aig_ManNodeNum(pGated) );
}
Vec_VecFree( vGates );
return pGated;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END