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/**CFile****************************************************************
FileName [bmcClp.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [SAT-based bounded model checking.]
Synopsis [INT-FX: Interpolation-based logic sharing extraction.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: bmcClp.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "bmc.h"
#include "misc/vec/vecWec.h"
#include "sat/cnf/cnf.h"
#include "sat/bsat/satStore.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
extern Cnf_Dat_t * Mf_ManGenerateCnf( Gia_Man_t * pGia, int nLutSize, int fCnfObjIds, int fAddOrCla, int fVerbose );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Performs one round of removing literals.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Bmc_CollapseExpandRound( sat_solver * pSat, sat_solver * pSatOn, Vec_Int_t * vLits, Vec_Int_t * vNums, Vec_Int_t * vTemp, int nBTLimit, int fCanon )
{
int k, n, iLit, status;
// try removing one literal at a time
for ( k = Vec_IntSize(vLits) - 1; k >= 0; k-- )
{
int Save = Vec_IntEntry( vLits, k );
if ( Save == -1 )
continue;
// check if this literal when expanded overlaps with the on-set
if ( pSatOn )
{
// it is ok to skip the first round if the literal is positive
if ( fCanon && !Abc_LitIsCompl(Save) )
continue;
// put into new array
Vec_IntClear( vTemp );
Vec_IntForEachEntry( vLits, iLit, n )
if ( iLit != -1 )
Vec_IntPush( vTemp, Abc_LitNotCond(iLit, k==n) );
// check against onset
status = sat_solver_solve( pSatOn, Vec_IntArray(vTemp), Vec_IntLimit(vTemp), nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return -1;
//printf( "%d", status == l_True );
if ( status == l_False )
continue;
// otherwise keep trying to remove it
}
Vec_IntWriteEntry( vLits, k, -1 );
// put into new array
Vec_IntClear( vTemp );
Vec_IntForEachEntry( vLits, iLit, n )
if ( iLit != -1 )
Vec_IntPush( vTemp, iLit );
// check against offset
status = sat_solver_solve( pSat, Vec_IntArray(vTemp), Vec_IntLimit(vTemp), nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return -1;
if ( status == l_True )
Vec_IntWriteEntry( vLits, k, Save );
}
// if ( pSatOn )
// printf( "\n" );
// put into new array
Vec_IntClear( vNums );
Vec_IntForEachEntry( vLits, iLit, n )
if ( iLit != -1 )
Vec_IntPush( vNums, n );
return 0;
}
/**Function*************************************************************
Synopsis [Expends minterm into a cube.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Bmc_CollapseExpand( sat_solver * pSat, sat_solver * pSatOn, Vec_Int_t * vLits, Vec_Int_t * vNums, Vec_Int_t * vTemp, int nBTLimit, int fCanon )
{
// perform one quick reduction if it is non-canonical
if ( !fCanon )
{
int i, k, iLit, status, nFinal, * pFinal;
// check against offset
status = sat_solver_solve( pSat, Vec_IntArray(vLits), Vec_IntLimit(vLits), nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return -1;
assert( status == l_False );
// get subset of literals
nFinal = sat_solver_final( pSat, &pFinal );
// mark unused literals
Vec_IntForEachEntry( vLits, iLit, i )
{
for ( k = 0; k < nFinal; k++ )
if ( iLit == Abc_LitNot(pFinal[k]) )
break;
if ( k == nFinal )
Vec_IntWriteEntry( vLits, i, -1 );
}
}
Bmc_CollapseExpandRound( pSat, pSatOn, vLits, vNums, vTemp, nBTLimit, fCanon );
Bmc_CollapseExpandRound( pSat, NULL, vLits, vNums, vTemp, nBTLimit, fCanon );
return 0;
}
/**Function*************************************************************
Synopsis [Returns SAT solver in the 'sat' state with the given assignment.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Bmc_ComputeCanonical( sat_solver * pSat, Vec_Int_t * vLits, Vec_Int_t * vTemp, int nBTLimit )
{
int i, k, iLit, status = l_Undef;
for ( i = 0; i < Vec_IntSize(vLits); i++ )
{
// copy the first i+1 literals
Vec_IntClear( vTemp );
Vec_IntForEachEntryStop( vLits, iLit, k, i+1 )
Vec_IntPush( vTemp, iLit );
// check if it satisfies the on-set
status = sat_solver_solve( pSat, Vec_IntArray(vTemp), Vec_IntLimit(vTemp), nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
return l_Undef;
if ( status == l_True )
continue;
// if it is UNSAT, try the opposite literal
iLit = Vec_IntEntry( vLits, i );
// if literal is positive, there is no way to flip it
if ( !Abc_LitIsCompl(iLit) )
return l_False;
Vec_IntWriteEntry( vLits, i, Abc_LitNot(iLit) );
Vec_IntForEachEntryStart( vLits, iLit, k, i+1 )
Vec_IntWriteEntry( vLits, k, Abc_LitNot(Abc_LitRegular(iLit)) );
// recheck
i--;
}
assert( status == l_True );
return status;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Str_t * Bmc_CollapseOneInt( Gia_Man_t * p, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose, int fCompl )
{
int fPrintMinterm = 0;
int nVars = Gia_ManCiNum(p);
Vec_Int_t * vVars = Vec_IntAlloc( nVars );
Vec_Int_t * vLits = Vec_IntAlloc( nVars );
Vec_Int_t * vLitsC= Vec_IntAlloc( nVars );
Vec_Int_t * vNums = Vec_IntAlloc( nVars );
Vec_Int_t * vCube = Vec_IntAlloc( nVars );
Vec_Str_t * vSop = Vec_StrAlloc( 100 );
int iOut = 0, iLit, iVar, status, n, Count, Start;
// create SAT solver
Cnf_Dat_t * pCnf = Mf_ManGenerateCnf( p, 8, 0, 0, 0 );
sat_solver * pSat[3] = {
(sat_solver *)Cnf_DataWriteIntoSolver(pCnf, 1, 0),
(sat_solver *)Cnf_DataWriteIntoSolver(pCnf, 1, 0),
fCanon ? (sat_solver *)Cnf_DataWriteIntoSolver(pCnf, 1, 0) : NULL
};
// collect CI variables
int iCiVarBeg = pCnf->nVars - nVars;// - 1;
if ( fReverse )
for ( n = nVars - 1; n >= 0; n-- )
Vec_IntPush( vVars, iCiVarBeg + n );
else
for ( n = 0; n < nVars; n++ )
Vec_IntPush( vVars, iCiVarBeg + n );
// start with all negative literals
Vec_IntForEachEntry( vVars, iVar, n )
Vec_IntPush( vLitsC, Abc_Var2Lit(iVar, 1) );
// check that on-set/off-set is sat
for ( n = 0; n < 2 + fCanon; n++ )
{
iLit = Abc_Var2Lit( iOut + 1, n&1 ); // n=0 => F=1 n=1 => F=0
status = sat_solver_addclause( pSat[n], &iLit, &iLit + 1 );
if ( status == 0 )
{
Vec_StrPrintStr( vSop, ((n&1) ^ fCompl) ? " 1\n" : " 0\n" );
Vec_StrPush( vSop, '\0' );
goto cleanup; // const0/1
}
status = sat_solver_solve( pSat[n], NULL, NULL, nBTLimit, 0, 0, 0 );
if ( status == l_Undef )
{
Vec_StrFreeP( &vSop );
goto cleanup; // timeout
}
if ( status == l_False )
{
Vec_StrPrintStr( vSop, ((n&1) ^ fCompl) ? " 1\n" : " 0\n" );
Vec_StrPush( vSop, '\0' );
goto cleanup; // const0/1
}
}
Vec_StrPush( vSop, '\0' );
// prepare on-set for solving
// if ( fCanon )
// sat_solver_prepare_enum( pSat[0], Vec_IntArray(vVars), Vec_IntSize(vVars) );
Count = 0;
while ( 1 )
{
// get the assignment
if ( fCanon )
status = Bmc_ComputeCanonical( pSat[0], vLitsC, vCube, nBTLimit );
else
{
sat_solver_clean_polarity( pSat[0], Vec_IntArray(vVars), Vec_IntSize(vVars) );
status = sat_solver_solve( pSat[0], NULL, NULL, 0, 0, 0, 0 );
}
if ( status == l_Undef )
{
Vec_StrFreeP( &vSop );
goto cleanup; // timeout
}
if ( status == l_False )
break;
// check number of cubes
if ( Count == nCubeLim )
{
//printf( "The number of cubes exceeded the limit (%d).\n", nCubeLim );
Vec_StrFreeP( &vSop );
goto cleanup; // cube out
}
// collect values
Vec_IntClear( vLits );
Vec_IntClear( vLitsC );
Vec_IntForEachEntry( vVars, iVar, n )
{
iLit = Abc_Var2Lit(iVar, !sat_solver_var_value(pSat[0], iVar));
Vec_IntPush( vLits, iLit );
Vec_IntPush( vLitsC, iLit );
}
// print minterm
if ( fPrintMinterm )
{
printf( "Mint: " );
Vec_IntForEachEntry( vLits, iLit, n )
printf( "%d", !Abc_LitIsCompl(iLit) );
printf( "\n" );
}
// expand the values
status = Bmc_CollapseExpand( pSat[1], fCanon ? pSat[2] : pSat[0], vLits, vNums, vCube, nBTLimit, fCanon );
if ( status < 0 )
{
Vec_StrFreeP( &vSop );
goto cleanup; // timeout
}
// collect cube
Vec_StrPop( vSop );
Start = Vec_StrSize( vSop );
Vec_StrFillExtra( vSop, Start + nVars + 4, '-' );
Vec_StrWriteEntry( vSop, Start + nVars + 0, ' ' );
Vec_StrWriteEntry( vSop, Start + nVars + 1, (char)(fCompl ? '0' : '1') );
Vec_StrWriteEntry( vSop, Start + nVars + 2, '\n' );
Vec_StrWriteEntry( vSop, Start + nVars + 3, '\0' );
Vec_IntClear( vCube );
Vec_IntForEachEntry( vNums, iVar, n )
{
iLit = Vec_IntEntry( vLits, iVar );
Vec_IntPush( vCube, Abc_LitNot(iLit) );
Vec_StrWriteEntry( vSop, Start + iVar, (char)('0' + !Abc_LitIsCompl(iLit)) );
}
if ( fVerbose )
printf( "Cube %4d: %s", Count, Vec_StrArray(vSop) + Start );
Count++;
// add cube
status = sat_solver_addclause( pSat[0], Vec_IntArray(vCube), Vec_IntLimit(vCube) );
if ( status == 0 )
break;
// add cube
if ( fCanon )
status = sat_solver_addclause( pSat[2], Vec_IntArray(vCube), Vec_IntLimit(vCube) );
assert( status == 1 );
}
//printf( "Finished enumerating %d assignments.\n", Count );
cleanup:
Vec_IntFree( vVars );
Vec_IntFree( vLits );
Vec_IntFree( vLitsC );
Vec_IntFree( vNums );
Vec_IntFree( vCube );
sat_solver_delete( pSat[0] );
sat_solver_delete( pSat[1] );
if ( fCanon )
sat_solver_delete( pSat[2] );
Cnf_DataFree( pCnf );
return vSop;
}
Vec_Str_t * Bmc_CollapseOne( Gia_Man_t * p, int nCubeLim, int nBTLimit, int fCanon, int fReverse, int fVerbose )
{
Vec_Str_t * vSopOn, * vSopOff;
int nCubesOn = ABC_INFINITY;
int nCubesOff = ABC_INFINITY;
vSopOn = Bmc_CollapseOneInt( p, nCubeLim, nBTLimit, fCanon, fReverse, fVerbose, 0 );
if ( vSopOn )
nCubesOn = Vec_StrCountEntry(vSopOn,'\n');
Gia_ObjFlipFaninC0( Gia_ManPo(p, 0) );
vSopOff = Bmc_CollapseOneInt( p, Abc_MinInt(nCubeLim, nCubesOn), nBTLimit, fCanon, fReverse, fVerbose, 1 );
Gia_ObjFlipFaninC0( Gia_ManPo(p, 0) );
if ( vSopOff )
nCubesOff = Vec_StrCountEntry(vSopOff,'\n');
if ( vSopOn == NULL )
return vSopOff;
if ( vSopOff == NULL )
return vSopOn;
if ( nCubesOn <= nCubesOff )
{
Vec_StrFree( vSopOff );
return vSopOn;
}
else
{
Vec_StrFree( vSopOn );
return vSopOff;
}
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
