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/**CFile****************************************************************
FileName [giaFalse.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Scalable AIG package.]
Synopsis [Detection and elimination of false paths.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: giaFalse.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
***********************************************************************/
#include "gia.h"
#include "misc/vec/vecQue.h"
#include "misc/vec/vecWec.h"
#include "sat/bsat/satStore.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Reconstruct the AIG after detecting false paths.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_ManFalseRebuildOne( Gia_Man_t * pNew, Gia_Man_t * p, Vec_Int_t * vHook, int fVerbose, int fVeryVerbose )
{
Gia_Obj_t * pObj, * pPrev = NULL;
int i, iObjValue, iPrevValue = -1;
if ( fVerbose )
{
printf( "Eliminating path: " );
Vec_IntPrint( vHook );
}
Gia_ManForEachObjVec( vHook, p, pObj, i )
{
if ( fVeryVerbose )
Gia_ObjPrint( p, pObj );
iObjValue = pObj->Value;
pObj->Value = i ? Gia_ManHashAnd(pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj)) : 0;
if ( pPrev )
pPrev->Value = iPrevValue;
iPrevValue = iObjValue;
pPrev = pObj;
}
}
Gia_Man_t * Gia_ManFalseRebuild( Gia_Man_t * p, Vec_Wec_t * vHooks, int fVerbose, int fVeryVerbose )
{
Gia_Man_t * pNew, * pTemp;
Gia_Obj_t * pObj;
int i, Counter = 0;
pNew = Gia_ManStart( 4 * Gia_ManObjNum(p) / 3 );
pNew->pName = Abc_UtilStrsav( p->pName );
pNew->pSpec = Abc_UtilStrsav( p->pSpec );
Gia_ManConst0(p)->Value = 0;
Gia_ManHashAlloc( pNew );
Gia_ManForEachObj1( p, pObj, i )
{
if ( Gia_ObjIsAnd(pObj) )
{
if ( Vec_WecLevelSize(vHooks, i) > 0 )
{
if ( fVerbose )
printf( "Path %d : ", Counter++ );
Gia_ManFalseRebuildOne( pNew, p, Vec_WecEntry(vHooks, i), fVerbose, fVeryVerbose );
}
else
pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
}
else if ( Gia_ObjIsCi(pObj) )
pObj->Value = Gia_ManAppendCi( pNew );
else if ( Gia_ObjIsCo(pObj) )
pObj->Value = Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
}
Gia_ManHashStop( pNew );
Gia_ManSetRegNum( pNew, Gia_ManRegNum(p) );
pNew = Gia_ManCleanup( pTemp = pNew );
Gia_ManStop( pTemp );
return pNew;
}
/**Function*************************************************************
Synopsis [Derive critical path by following minimum slacks.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_ManCollectPath_rec( Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vPath )
{
if ( Gia_ObjIsAnd(pObj) )
{
if ( Gia_ObjLevel(p, Gia_ObjFanin0(pObj)) > Gia_ObjLevel(p, Gia_ObjFanin1(pObj)) )
Gia_ManCollectPath_rec( p, Gia_ObjFanin0(pObj), vPath );
else if ( Gia_ObjLevel(p, Gia_ObjFanin0(pObj)) < Gia_ObjLevel(p, Gia_ObjFanin1(pObj)) )
Gia_ManCollectPath_rec( p, Gia_ObjFanin1(pObj), vPath );
// else if ( rand() & 1 )
// Gia_ManCollectPath_rec( p, Gia_ObjFanin0(pObj), vPath );
else
Gia_ManCollectPath_rec( p, Gia_ObjFanin1(pObj), vPath );
}
Vec_IntPush( vPath, Gia_ObjId(p, pObj) );
}
Vec_Int_t * Gia_ManCollectPath( Gia_Man_t * p, Gia_Obj_t * pObj )
{
Vec_Int_t * vPath = Vec_IntAlloc( p->nLevels );
Gia_ManCollectPath_rec( p, Gia_ObjFanin0(pObj), vPath );
return vPath;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gia_ManCheckFalseOne( Gia_Man_t * p, int iOut, int nTimeOut, Vec_Wec_t * vHooks, int fVerbose, int fVeryVerbose )
{
sat_solver * pSat;
Gia_Obj_t * pObj;
Gia_Obj_t * pPivot = Gia_ManCo( p, iOut );
Vec_Int_t * vLits = Vec_IntAlloc( p->nLevels );
Vec_Int_t * vPath = Gia_ManCollectPath( p, pPivot );
int nLits = 0, * pLits = NULL;
int i, Shift[2], status;
abctime clkStart = Abc_Clock();
// collect objects and assign SAT variables
int iFanin = Gia_ObjFaninId0p( p, pPivot );
Vec_Int_t * vObjs = Gia_ManCollectNodesCis( p, &iFanin, 1 );
Gia_ManForEachObjVec( vObjs, p, pObj, i )
pObj->Value = Vec_IntSize(vObjs) - 1 - i;
assert( Gia_ObjIsCo(pPivot) );
// create SAT solver
pSat = sat_solver_new();
sat_solver_set_runtime_limit( pSat, nTimeOut ? nTimeOut * CLOCKS_PER_SEC + Abc_Clock(): 0 );
sat_solver_setnvars( pSat, Vec_IntSize(vPath) + 2 * Vec_IntSize(vObjs) );
Shift[0] = Vec_IntSize(vPath);
Shift[1] = Vec_IntSize(vPath) + Vec_IntSize(vObjs);
// add CNF for the path
Gia_ManForEachObjVec( vPath, p, pObj, i )
{
sat_solver_add_xor( pSat, i, pObj->Value + Shift[0], pObj->Value + Shift[1], 0 );
Vec_IntPush( vLits, Abc_Var2Lit(i, 0) );
}
// add CNF for the cone
Gia_ManForEachObjVec( vObjs, p, pObj, i )
{
if ( !Gia_ObjIsAnd(pObj) )
continue;
sat_solver_add_and( pSat, pObj->Value + Shift[0],
Gia_ObjFanin0(pObj)->Value + Shift[0], Gia_ObjFanin1(pObj)->Value + Shift[0],
Gia_ObjFaninC0(pObj), Gia_ObjFaninC1(pObj) );
sat_solver_add_and( pSat, pObj->Value + Shift[1],
Gia_ObjFanin0(pObj)->Value + Shift[1], Gia_ObjFanin1(pObj)->Value + Shift[1],
Gia_ObjFaninC0(pObj), Gia_ObjFaninC1(pObj) );
}
// call the SAT solver
status = sat_solver_solve( pSat, Vec_IntArray(vLits), Vec_IntArray(vLits) + Vec_IntSize(vLits), (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0, (ABC_INT64_T)0 );
if ( status == l_False )
{
int iBeg, iEnd;
nLits = sat_solver_final( pSat, &pLits );
iBeg = Abc_Lit2Var(pLits[nLits-1]);
iEnd = Abc_Lit2Var(pLits[0]);
if ( iEnd - iBeg < 20 )
{
// check if nodes on the path are already used
for ( i = iBeg; i <= iEnd; i++ )
if ( Vec_WecLevelSize(vHooks, Vec_IntEntry(vPath, i)) > 0 )
break;
if ( i > iEnd )
{
Vec_Int_t * vHook = Vec_WecEntry(vHooks, Vec_IntEntry(vPath, iEnd));
for ( i = iBeg; i <= iEnd; i++ )
Vec_IntPush( vHook, Vec_IntEntry(vPath, i) );
}
}
}
if ( fVerbose )
{
printf( "PO %6d : Level = %3d ", iOut, Gia_ObjLevel(p, pPivot) );
if ( status == l_Undef )
printf( "Timeout reached after %d seconds. ", nTimeOut );
else if ( status == l_True )
printf( "There is no false path. " );
else
{
printf( "False path contains %d nodes (out of %d): ", nLits, Vec_IntSize(vLits) );
printf( "top = %d ", Vec_IntEntry(vPath, Abc_Lit2Var(pLits[0])) );
if ( fVeryVerbose )
for ( i = 0; i < nLits; i++ )
printf( "%d ", Abc_Lit2Var(pLits[i]) );
printf( " " );
}
Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
}
sat_solver_delete( pSat );
Vec_IntFree( vObjs );
Vec_IntFree( vPath );
Vec_IntFree( vLits );
}
Gia_Man_t * Gia_ManCheckFalse( Gia_Man_t * p, int nSlackMax, int nTimeOut, int fVerbose, int fVeryVerbose )
{
Gia_Man_t * pNew;
Vec_Wec_t * vHooks;
Vec_Que_t * vPrio;
Vec_Flt_t * vWeights;
Gia_Obj_t * pObj;
int i;
srand( 111 );
Gia_ManLevelNum( p );
// create PO weights
vWeights = Vec_FltAlloc( Gia_ManCoNum(p) );
Gia_ManForEachCo( p, pObj, i )
Vec_FltPush( vWeights, Gia_ObjLevel(p, pObj) );
// put POs into the queue
vPrio = Vec_QueAlloc( Gia_ManCoNum(p) );
Vec_QueSetPriority( vPrio, Vec_FltArrayP(vWeights) );
Gia_ManForEachCo( p, pObj, i )
Vec_QuePush( vPrio, i );
// work on each PO in the queue
vHooks = Vec_WecStart( Gia_ManObjNum(p) );
while ( Vec_QueTopPriority(vPrio) >= p->nLevels - nSlackMax )
Gia_ManCheckFalseOne( p, Vec_QuePop(vPrio), nTimeOut, vHooks, fVerbose, fVeryVerbose );
if ( fVerbose )
printf( "Collected %d non-overlapping false paths.\n", Vec_WecSizeUsed(vHooks) );
// reconstruct the AIG
pNew = Gia_ManFalseRebuild( p, vHooks, fVerbose, fVeryVerbose );
// cleanup
Vec_WecFree( vHooks );
Vec_FltFree( vWeights );
Vec_QueFree( vPrio );
return pNew;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
