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/**CFile****************************************************************
FileName [giaCsat0.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Scalable AIG package.]
Synopsis [Circuit-based SAT solver.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: giaCsat0.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "gia.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static inline int Sat_ObjXValue( Gia_Obj_t * pObj ) { return (pObj->fMark1 << 1) | pObj->fMark0; }
static inline void Sat_ObjSetXValue( Gia_Obj_t * pObj, int v) { pObj->fMark0 = (v & 1); pObj->fMark1 = ((v >> 1) & 1); }
static inline int Sat_VarIsAssigned( Gia_Obj_t * pVar ) { return pVar->Value > 0; }
static inline void Sat_VarAssign( Gia_Obj_t * pVar, int i ) { assert(!pVar->Value); pVar->Value = i; }
static inline void Sat_VarUnassign( Gia_Obj_t * pVar ) { assert(pVar->Value); pVar->Value = 0; }
static inline int Sat_VarValue( Gia_Obj_t * pVar ) { assert(pVar->Value); return pVar->fMark0; }
static inline void Sat_VarSetValue( Gia_Obj_t * pVar, int v ) { assert(pVar->Value); pVar->fMark0 = v; }
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Collects nodes in the cone and initialized them to x.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_SatCollectCone_rec( Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vVisit )
{
if ( Sat_ObjXValue(pObj) == GIA_UND )
return;
assert( pObj->Value == 0 );
if ( Gia_ObjIsAnd(pObj) )
{
Gia_SatCollectCone_rec( p, Gia_ObjFanin0(pObj), vVisit );
Gia_SatCollectCone_rec( p, Gia_ObjFanin1(pObj), vVisit );
}
assert( Sat_ObjXValue(pObj) == 0 );
Sat_ObjSetXValue( pObj, GIA_UND );
Vec_IntPush( vVisit, Gia_ObjId(p, pObj) );
}
/**Function*************************************************************
Synopsis [Collects nodes in the cone and initialized them to x.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_SatCollectCone( Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vVisit )
{
assert( !Gia_IsComplement(pObj) );
assert( !Gia_ObjIsConst0(pObj) );
assert( Sat_ObjXValue(pObj) == 0 );
Vec_IntClear( vVisit );
Gia_SatCollectCone_rec( p, pObj, vVisit );
}
/**Function*************************************************************
Synopsis [Collects nodes in the cone.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_SatVerifyPattern( Gia_Man_t * p, Gia_Obj_t * pRoot, Vec_Int_t * vCex, Vec_Int_t * vVisit )
{
Gia_Obj_t * pObj;
int i, Entry, Value, Value0, Value1;
assert( Gia_ObjIsCo(pRoot) );
assert( !Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) );
// collect nodes and initialized them to x
Gia_SatCollectCone( p, Gia_ObjFanin0(pRoot), vVisit );
// set binary values to nodes in the counter-example
Vec_IntForEachEntry( vCex, Entry, i )
{
pObj = Gia_NotCond( Gia_ManObj( p, Gia_Lit2Var(Entry) ), Gia_LitIsCompl(Entry) );
Sat_ObjSetXValue( Gia_Regular(pObj), Gia_IsComplement(pObj)? GIA_ZER : GIA_ONE );
assert( Sat_ObjXValue(Gia_Regular(pObj)) == (Gia_IsComplement(pObj)? GIA_ZER : GIA_ONE) );
}
// simulate
Gia_ManForEachObjVec( vVisit, p, pObj, i )
{
if ( Gia_ObjIsCi(pObj) )
continue;
assert( Gia_ObjIsAnd(pObj) );
Value0 = Sat_ObjXValue( Gia_ObjFanin0(pObj) );
Value1 = Sat_ObjXValue( Gia_ObjFanin1(pObj) );
Value = Gia_XsimAndCond( Value0, Gia_ObjFaninC0(pObj), Value1, Gia_ObjFaninC1(pObj) );
Sat_ObjSetXValue( pObj, Value );
}
Value = Gia_XsimNotCond( Value, Gia_ObjFaninC0(pRoot) );
if ( Value != GIA_ONE )
printf( "Gia_SatVerifyPattern(): Verification failed.\n" );
assert( Value == GIA_ONE );
// clean the nodes
Gia_ManForEachObjVec( vVisit, p, pObj, i )
Sat_ObjSetXValue( pObj, 0 );
}
/**Function*************************************************************
Synopsis [Undoes the assignment since the given value.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_SatUndo_rec( Gia_Obj_t * pObj, unsigned Value, Vec_Int_t * vCex )
{
if ( pObj->Value < Value )
return;
pObj->Value = 0;
if ( Gia_ObjIsCi(pObj) )
{
if ( vCex ) Vec_IntPush( vCex, Gia_Var2Lit(Gia_ObjCioId(pObj), !pObj->fPhase) );
return;
}
Gia_SatUndo_rec( Gia_ObjFanin0(pObj), Value, vCex );
Gia_SatUndo_rec( Gia_ObjFanin1(pObj), Value, vCex );
}
/**Function*************************************************************
Synopsis [Propagates assignments.]
Description [Returns 1 if UNSAT, 0 if SAT.]
SideEffects []
SeeAlso []
***********************************************************************/
int Gia_SatProp_rec( Gia_Obj_t * pObj, unsigned Phase, unsigned * pValue, int * pnConfs )
{
int Value = *pValue;
if ( pObj->Value )
return pObj->fPhase != Phase;
if ( Gia_ObjIsCi(pObj) )
{
pObj->Value = Value;
pObj->fPhase = Phase;
return 0;
}
if ( Phase ) // output of AND should be 1
{
if ( Gia_SatProp_rec( Gia_ObjFanin0(pObj), !Gia_ObjFaninC0(pObj), pValue, pnConfs ) )
return 1;
if ( Gia_SatProp_rec( Gia_ObjFanin1(pObj), !Gia_ObjFaninC1(pObj), pValue, pnConfs ) )
{
Gia_SatUndo_rec( Gia_ObjFanin0(pObj), Value, NULL );
return 1;
}
/*
if ( Gia_SatProp_rec( Gia_ObjFanin1(pObj), !Gia_ObjFaninC1(pObj), pValue, pnConfs ) )
return 1;
if ( Gia_SatProp_rec( Gia_ObjFanin0(pObj), !Gia_ObjFaninC0(pObj), pValue, pnConfs ) )
{
Gia_SatUndo_rec( Gia_ObjFanin1(pObj), Value, NULL );
return 1;
}
*/
pObj->Value = Value;
pObj->fPhase = 1;
return 0;
}
// output of AND should be 0
(*pValue)++;
if ( !Gia_SatProp_rec( Gia_ObjFanin1(pObj), Gia_ObjFaninC1(pObj), pValue, pnConfs ) )
{
pObj->Value = Value;
pObj->fPhase = 0;
return 0;
}
if ( !*pnConfs )
return 1;
(*pValue)++;
if ( !Gia_SatProp_rec( Gia_ObjFanin0(pObj), Gia_ObjFaninC0(pObj), pValue, pnConfs ) )
{
pObj->Value = Value;
pObj->fPhase = 0;
return 0;
}
if ( !*pnConfs )
return 1;
// cannot be satisfied
(*pnConfs)--;
return 1;
}
/**Function*************************************************************
Synopsis [Procedure to solve SAT for the node.]
Description [Returns 1 if UNSAT, 0 if SAT, and -1 if undecided.]
SideEffects [Precondition: pObj->Value should be 0.]
SeeAlso []
***********************************************************************/
int Gia_SatSolve( Gia_Obj_t * pObj, unsigned Phase, int nConfsMax, Vec_Int_t * vCex )
{
int Value = 1;
int nConfs = nConfsMax? nConfsMax : (1<<30);
assert( !Gia_IsComplement(pObj) );
assert( !Gia_ObjIsConst0(pObj) );
assert( pObj->Value == 0 );
if ( Gia_SatProp_rec( pObj, Phase, &Value, &nConfs ) )
{
// if ( nConfs )
// printf( "UNSAT after %d conflicts\n", nConfsMax - nConfs );
// else
// printf( "UNDEC after %d conflicts\n", nConfsMax );
return nConfs? 1 : -1;
}
Vec_IntClear( vCex );
Gia_SatUndo_rec( pObj, 1, vCex );
// printf( "SAT after %d conflicts\n", nConfsMax - nConfs );
return 0;
}
/**Function*************************************************************
Synopsis [Procedure to test the new SAT solver.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_SatSolveTest( Gia_Man_t * p )
{
int nConfsMax = 1000;
int CountUnsat, CountSat, CountUndec;
Vec_Int_t * vCex;
Vec_Int_t * vVisit;
Gia_Obj_t * pRoot;
int i, RetValue, clk = clock();
// prepare AIG
Gia_ManCleanValue( p );
Gia_ManCleanMark0( p );
Gia_ManCleanMark1( p );
vCex = Vec_IntAlloc( 100 );
vVisit = Vec_IntAlloc( 100 );
// solve for each output
CountUnsat = CountSat = CountUndec = 0;
Gia_ManForEachCo( p, pRoot, i )
{
if ( Gia_ObjIsConst0(Gia_ObjFanin0(pRoot)) )
continue;
//printf( "Output %6d : ", i );
RetValue = Gia_SatSolve( Gia_ObjFanin0(pRoot), !Gia_ObjFaninC0(pRoot), nConfsMax, vCex );
if ( RetValue == 1 )
CountUnsat++;
else if ( RetValue == -1 )
CountUndec++;
else
{
// Gia_Obj_t * pTemp;
// int k;
assert( RetValue == 0 );
CountSat++;
/*
Vec_IntForEachEntry( vCex, pTemp, k )
// printf( "%s%d ", Gia_IsComplement(pTemp)? "!": "", Gia_ObjCioId(Gia_Regular(pTemp)) );
printf( "%s%d ", Gia_IsComplement(pTemp)? "!": "", Gia_ObjId(p,Gia_Regular(pTemp)) );
printf( "\n" );
*/
// Gia_SatVerifyPattern( p, pRoot, vCex, vVisit );
}
// Gia_ManCheckMark0( p );
// Gia_ManCheckMark1( p );
}
Vec_IntFree( vCex );
Vec_IntFree( vVisit );
printf( "Unsat = %d. Sat = %d. Undec = %d. ", CountUnsat, CountSat, CountUndec );
ABC_PRT( "Time", clock() - clk );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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