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/**CFile****************************************************************
FileName [sfmSat.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [SAT-based optimization using internal don't-cares.]
Synopsis [SAT-based procedures.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: sfmSat.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "sfmInt.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static word s_Truths6[6] = {
ABC_CONST(0xAAAAAAAAAAAAAAAA),
ABC_CONST(0xCCCCCCCCCCCCCCCC),
ABC_CONST(0xF0F0F0F0F0F0F0F0),
ABC_CONST(0xFF00FF00FF00FF00),
ABC_CONST(0xFFFF0000FFFF0000),
ABC_CONST(0xFFFFFFFF00000000)
};
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Creates order of objects in the SAT solver.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Sfm_NtkOrderObjects( Sfm_Ntk_t * p )
{
int i, iNode;
assert( Vec_IntEntryLast(p->vNodes) == Vec_IntEntry(p->vDivs, Vec_IntSize(p->vLeaves) + Vec_IntSize(p->vNodes)) );
Vec_IntClear( p->vOrder );
Vec_IntForEachEntryReverse( p->vNodes, iNode, i )
Vec_IntPush( p->vOrder, iNode );
Vec_IntForEachEntryStart( p->vDivs, iNode, i, Vec_IntSize(p->vLeaves) + Vec_IntSize(p->vNodes) )
Vec_IntPush( p->vOrder, iNode );
}
/**Function*************************************************************
Synopsis [Converts a window into a SAT solver.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Sfm_NtkWindowToSolver( Sfm_Ntk_t * p )
{
Vec_Int_t * vClause;
int RetValue, Lit, iNode = -1, iFanin, i, k;
clock_t clk = clock();
sat_solver * pSat0 = sat_solver_new();
sat_solver * pSat1 = sat_solver_new();
sat_solver_setnvars( pSat0, 1 + Vec_IntSize(p->vDivs) + 2 * Vec_IntSize(p->vTfo) + Vec_IntSize(p->vRoots) + 100 );
sat_solver_setnvars( pSat1, 1 + Vec_IntSize(p->vDivs) + 2 * Vec_IntSize(p->vTfo) + Vec_IntSize(p->vRoots) + 100 );
// create SAT variables
p->nSatVars = 1;
Vec_IntForEachEntryReverse( p->vNodes, iNode, i )
Sfm_ObjSetSatVar( p, iNode, p->nSatVars++ );
Vec_IntForEachEntryReverse( p->vLeaves, iNode, i )
Sfm_ObjSetSatVar( p, iNode, p->nSatVars++ );
Vec_IntForEachEntryReverse( p->vDivs, iNode, i )
Sfm_ObjSetSatVar( p, iNode, p->nSatVars++ );
// add CNF clauses for the TFI
Sfm_NtkOrderObjects( p );
Vec_IntForEachEntry( p->vOrder, iNode, i )
{
// collect fanin variables
Vec_IntClear( p->vFaninMap );
Sfm_ObjForEachFanin( p, iNode, iFanin, k )
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iFanin) );
Vec_IntPush( p->vFaninMap, Sfm_ObjSatVar(p, iNode) );
// generate CNF
Sfm_TranslateCnf( p->vClauses, (Vec_Str_t *)Vec_WecEntry(p->vCnfs, iNode), p->vFaninMap );
// add clauses
Vec_WecForEachLevel( p->vClauses, vClause, k )
{
if ( Vec_IntSize(vClause) == 0 )
break;
RetValue = sat_solver_addclause( pSat0, Vec_IntArray(vClause), Vec_IntArray(vClause) + Vec_IntSize(vClause) );
assert( RetValue );
RetValue = sat_solver_addclause( pSat1, Vec_IntArray(vClause), Vec_IntArray(vClause) + Vec_IntSize(vClause) );
assert( RetValue );
}
}
// get the last node
iNode = Vec_IntEntryLast( p->vNodes );
// add unit clause
Lit = Abc_Var2Lit( Sfm_ObjSatVar(p, iNode), 1 );
RetValue = sat_solver_addclause( pSat0, &Lit, &Lit + 1 );
assert( RetValue );
// add unit clause
Lit = Abc_Var2Lit( Sfm_ObjSatVar(p, iNode), 0 );
RetValue = sat_solver_addclause( pSat1, &Lit, &Lit + 1 );
assert( RetValue );
// finalize
sat_solver_compress( pSat0 );
sat_solver_compress( pSat1 );
// return the result
assert( p->pSat0 == NULL );
assert( p->pSat1 == NULL );
p->pSat0 = pSat0;
p->pSat1 = pSat1;
p->timeCnf += clock() - clk;
}
/**Function*************************************************************
Synopsis [Takes SAT solver and returns interpolant.]
Description [If interpolant does not exist, records difference variables.]
SideEffects []
SeeAlso []
***********************************************************************/
word Sfm_ComputeInterpolant( Sfm_Ntk_t * p )
{
word * pSign, uCube, uTruth = 0;
int status, i, Div, iVar, nFinal, * pFinal;
int nVars = sat_solver_nvars( p->pSat1 );
int iNewLit = Abc_Var2Lit( nVars, 0 );
sat_solver_setnvars( p->pSat1, nVars + 1 );
while ( 1 )
{
// find onset minterm
status = sat_solver_solve( p->pSat1, &iNewLit, &iNewLit + 1, p->pPars->nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_False )
return uTruth;
assert( status == l_True );
// collect divisor literals
Vec_IntClear( p->vLits );
Vec_IntForEachEntry( p->vDivIds, Div, i )
Vec_IntPush( p->vLits, sat_solver_var_literal(p->pSat1, Div) );
// check against offset
status = sat_solver_solve( p->pSat0, Vec_IntArray(p->vLits), Vec_IntArray(p->vLits) + Vec_IntSize(p->vLits), p->pPars->nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_True )
break;
assert( status == l_False );
// compute cube and add clause
nFinal = sat_solver_final( p->pSat0, &pFinal );
uCube = ~(word)0;
Vec_IntClear( p->vLits );
Vec_IntPush( p->vLits, Abc_LitNot(iNewLit) );
for ( i = 0; i < nFinal; i++ )
{
Vec_IntPush( p->vLits, pFinal[i] );
iVar = Vec_IntFind( p->vDivIds, Abc_Lit2Var(pFinal[i]) ); assert( iVar >= 0 );
uCube &= Abc_LitIsCompl(pFinal[i]) ? s_Truths6[iVar] : ~s_Truths6[iVar];
}
uTruth |= uCube;
status = sat_solver_addclause( p->pSat1, Vec_IntArray(p->vLits), Vec_IntArray(p->vLits) + Vec_IntSize(p->vLits) );
assert( status );
}
assert( status == l_True );
// store the counter-example
Vec_IntForEachEntry( p->vDivVars, iVar, i )
if ( sat_solver_var_value(p->pSat1, iVar) ^ sat_solver_var_value(p->pSat0, iVar) ) // insert 1
{
pSign = Vec_WrdEntryP( p->vDivCexes, i );
assert( !Abc_InfoHasBit( (unsigned *)pSign, p->nCexes) );
Abc_InfoXorBit( (unsigned *)pSign, p->nCexes );
}
p->nCexes++;
return SFM_SAT_SAT;
}
/**Function*************************************************************
Synopsis [Checks resubstitution.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
/*
void Sfm_ComputeInterpolantCheck( Sfm_Ntk_t * p )
{
int iNode = 3;
int iDiv0 = 6;
int iDiv1 = 7;
word uTruth;
// int i;
// Sfm_NtkForEachNode( p, i )
{
Sfm_NtkCreateWindow( p, iNode, 1 );
Sfm_NtkWindowToSolver( p );
// collect SAT variables of divisors
Vec_IntClear( p->vDivIds );
Vec_IntPush( p->vDivIds, Sfm_ObjSatVar(p, iDiv0) );
Vec_IntPush( p->vDivIds, Sfm_ObjSatVar(p, iDiv1) );
uTruth = Sfm_ComputeInterpolant( p->pSat1, p->pSat0, p->vDivIds, p->vLits, p->vDiffs, 0 );
if ( uTruth == SFM_SAT_SAT )
printf( "The problem is SAT.\n" );
else if ( uTruth == SFM_SAT_UNDEC )
printf( "The problem is UNDEC.\n" );
else
Kit_DsdPrintFromTruth( (unsigned *)&uTruth, 2 ); printf( "\n" );
Sfm_NtkCleanVars( p, p->nSatVars );
sat_solver_delete( p->pSat0 ); p->pSat0 = NULL;
sat_solver_delete( p->pSat1 ); p->pSat1 = NULL;
}
}
*/
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
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