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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 [Converts a window into a SAT solver.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Sfm_NtkWin2Sat( Sfm_Ntk_t * p )
{
Vec_Int_t * vClause;
int RetValue, Lit, iNode = -1, iFanin, i, k, c;
sat_solver * pSat0 = sat_solver_new();
sat_solver * pSat1 = sat_solver_new();
sat_solver_setnvars( pSat0, 1 + Vec_IntSize(p->vLeaves) + Vec_IntSize(p->vNodes) + 2 * Vec_IntSize(p->vTfo) + Vec_IntSize(p->vRoots) );
sat_solver_setnvars( pSat1, 1 + Vec_IntSize(p->vLeaves) + Vec_IntSize(p->vNodes) + 2 * Vec_IntSize(p->vTfo) + Vec_IntSize(p->vRoots) );
// 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 ( c = 0; c < 2; c++ )
{
Vec_Int_t * vObjs = c ? p->vDivs : p->vNodes;
Vec_IntForEachEntryReverse( vObjs, iNode, i )
{
// collect fanin variables
Vec_IntClear( p->vFaninMap );
Sfm_NodeForEachFanin( 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;
}
/**Function*************************************************************
Synopsis [Takes SAT solver and returns interpolant.]
Description [If interpolant does not exist, returns diff SAT variables.]
SideEffects []
SeeAlso []
***********************************************************************/
word Sfm_ComputeInterpolant( sat_solver * pSatOn, sat_solver * pSatOff, Vec_Int_t * vDivIds, Vec_Int_t * vLits, Vec_Int_t * vDiffs, int nBTLimit )
{
word uTruth = 0, uCube;
int status, i, Div, iVar, nFinal, * pFinal;
int nVars = sat_solver_nvars(pSatOn);
int iNewLit = Abc_Var2Lit( nVars, 0 );
int RetValue;
sat_solver_setnvars( pSatOn, nVars + 1 );
while ( 1 )
{
// find onset minterm
status = sat_solver_solve( pSatOn, &iNewLit, &iNewLit + 1, nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_False )
return uTruth;
assert( status == l_True );
// collect literals
Vec_IntClear( vLits );
Vec_IntForEachEntry( vDivIds, Div, i )
// Vec_IntPush( vLits, Abc_LitNot(sat_solver_var_literal(pSatOn, Div)) );
Vec_IntPush( vLits, sat_solver_var_literal(pSatOn, Div) );
// check against offset
status = sat_solver_solve( pSatOff, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits), nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return SFM_SAT_UNDEC;
if ( status == l_True )
{
Vec_IntClear( vDiffs );
for ( i = 0; i < nVars; i++ )
Vec_IntPush( vDiffs, sat_solver_var_value(pSatOn, i) ^ sat_solver_var_value(pSatOff, i) );
return SFM_SAT_SAT;
}
assert( status == l_False );
// compute cube and add clause
nFinal = sat_solver_final( pSatOff, &pFinal );
uCube = ~(word)0;
Vec_IntClear( vLits );
Vec_IntPush( vLits, Abc_LitNot(iNewLit) );
for ( i = 0; i < nFinal; i++ )
{
Vec_IntPush( vLits, pFinal[i] );
iVar = Vec_IntFind( vDivIds, Abc_Lit2Var(pFinal[i]) ); assert( iVar >= 0 );
uCube &= Abc_LitIsCompl(pFinal[i]) ? s_Truths6[iVar] : ~s_Truths6[iVar];
}
uTruth |= uCube;
RetValue = sat_solver_addclause( pSatOn, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits) );
assert( RetValue );
}
assert( 0 );
return 0;
}
/**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_NtkWindow( p, iNode, 1 );
Sfm_NtkWin2Sat( 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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