False path detection.

1 files changed, 216 insertions, 0 deletions

diff --git a/src/aig/gia/giaFalse.c b/src/aig/gia/giaFalse.c
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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 "sat/bsat/satStore.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Compute slacks measured using the number of AIG levels.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Gia_ManComputeSlacks( Gia_Man_t * p )
+{
+    Gia_Obj_t * pObj;
+    int i, nLevels = Gia_ManLevelNum( p );
+    Vec_Int_t * vLevelR = Gia_ManReverseLevel( p );
+    Vec_Int_t * vSlacks = Vec_IntAlloc( Gia_ManObjNum(p) );
+    Gia_ManForEachObj( p, pObj, i )
+        Vec_IntPush( vSlacks, nLevels - Gia_ObjLevelId(p, i) - Vec_IntEntry(vLevelR, i) );
+    assert( Vec_IntSize(vSlacks) == Gia_ManObjNum(p) );
+    Vec_IntFree( vLevelR );
+    return vSlacks;
+}
+
+/**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 * vSlacks, Vec_Int_t * vPath )
+{
+    if ( Gia_ObjIsAnd(pObj) )
+    {
+        int Slack = Vec_IntEntry(vSlacks, Gia_ObjId(p, pObj));
+        int Slack0 = Vec_IntEntry(vSlacks, Gia_ObjFaninId0p(p, pObj));
+        int Slack1 = Vec_IntEntry(vSlacks, Gia_ObjFaninId1p(p, pObj));
+        assert( Slack == Slack0 || Slack == Slack1 );
+        if ( Slack == Slack0 )
+            Gia_ManCollectPath_rec( p, Gia_ObjFanin0(pObj), vSlacks, vPath );
+        else 
+            Gia_ManCollectPath_rec( p, Gia_ObjFanin1(pObj), vSlacks, vPath );
+    }
+    Vec_IntPush( vPath, Gia_ObjId(p, pObj) );
+}
+Vec_Int_t * Gia_ManCollectPath( Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vSlacks )
+{
+    Vec_Int_t * vPath = Vec_IntAlloc( p->nLevels );
+    assert( Gia_ObjIsCo(pObj) );
+    Gia_ManCollectPath_rec( p, Gia_ObjFanin0(pObj), vSlacks, vPath );
+    return vPath;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManCheckFalseOne( Gia_Man_t * p, int iOut, int nTimeOut, Vec_Int_t * vSlacks )
+{
+    sat_solver * pSat;
+    Gia_Obj_t * pObj = Gia_ManCo( p, iOut );
+    Vec_Int_t * vLits = Vec_IntAlloc( p->nLevels );
+    Vec_Int_t * vPath = Gia_ManCollectPath( p, pObj, vSlacks );
+    int i, Shift[2], status, nLits, * pLits;
+    abctime clkStart = Abc_Clock();
+    // collect objects and assign SAT variables
+    int iFanin = Gia_ObjFaninId0p( p, pObj );
+    Vec_Int_t * vObjs = Gia_ManCollectNodesCis( p, &iFanin, 1 );
+    Gia_ManForEachObjVec( vObjs, p, pObj, i )
+        pObj->Value = Vec_IntSize(vObjs) - 1 - i;
+    // 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) ); 
+    }
+    printf( "PO %6d : ", iOut );
+    // 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_Undef )
+        printf( "Timeout reached after %d seconds. ", nTimeOut );
+    else if ( status == l_True )
+        printf( "There is no false path. " );
+    else
+    {
+        assert( status == l_False );
+        // call analize_final
+        nLits = sat_solver_final( pSat, &pLits );
+        printf( "False path contains %d nodes (out of %d):  ", nLits, Vec_IntSize(vLits) );
+        printf( "top = %d  ", Vec_IntEntry(vPath, Abc_Lit2Var(pLits[0])) );
+        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 );
+}
+void Gia_ManCheckFalse( Gia_Man_t * p, int nSlackMax, int nTimeOut )
+{
+    Vec_Que_t * vPrio;
+    Vec_Flt_t * vWeights;
+    Vec_Int_t * vSlacks;
+    Gia_Obj_t * pObj;
+    int i;
+    vSlacks = Gia_ManComputeSlacks(p);
+//Vec_IntPrint( vSlacks );
+    // create PO weights
+    vWeights = Vec_FltAlloc( Gia_ManCoNum(p) );
+    Gia_ManForEachCo( p, pObj, i )
+        Vec_FltPush( vWeights, p->nLevels - Vec_IntEntry(vSlacks, Gia_ObjId(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
+    while ( Vec_QueTopPriority(vPrio) >= p->nLevels - nSlackMax )
+        Gia_ManCheckFalseOne( p, Vec_QuePop(vPrio), nTimeOut, vSlacks );
+    // cleanup
+    Vec_IntFree( vSlacks );
+    Vec_FltFree( vWeights );
+    Vec_QueFree( vPrio );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManCheckFalseTest( Gia_Man_t * p, int nSlackMax )
+{
+    Gia_ManCheckFalse( p, nSlackMax, 0 );
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+