Adding switch to stop scorr if refinement is too slow.

src/base/abci/abcDar.c

@@ -2302,7 +2302,7 @@ Abc_Ntk_t * Abc_NtkDarLcorr( Abc_Ntk_t * pNtk, int nFramesP, int nConfMax, int f
   SeeAlso     []
  
 ***********************************************************************/
-Abc_Ntk_t * Abc_NtkDarLcorrNew( Abc_Ntk_t * pNtk, int nVarsMax, int nConfMax, int fVerbose )
+Abc_Ntk_t * Abc_NtkDarLcorrNew( Abc_Ntk_t * pNtk, int nVarsMax, int nConfMax, int nLimitMax, int fVerbose )
 {
     Ssw_Pars_t Pars, * pPars = &Pars;
     Aig_Man_t * pMan, * pTemp;
@@ -2314,6 +2314,7 @@ Abc_Ntk_t * Abc_NtkDarLcorrNew( Abc_Ntk_t * pNtk, int nVarsMax, int nConfMax, in
     pPars->fLatchCorrOpt = 1;
     pPars->nBTLimit      = nConfMax;
     pPars->nSatVarMax    = nVarsMax;
+    pPars->nLimitMax     = nLimitMax;
     pPars->fVerbose      = fVerbose;
     pMan = Ssw_SignalCorrespondence( pTemp = pMan, pPars );
     Aig_ManStop( pTemp );

src/proof/cec/cec.h

@@ -149,6 +149,7 @@ struct Cec_ParCor_t_
     int              nBTLimit;      // conflict limit at a node
     int              nLevelMax;     // (scorr only) the max number of levels
     int              nStepsMax;     // (scorr only) the max number of induction steps
+    int              nLimitMax;     // (scorr only) stop after this many iterations if little or no improvement
     int              fLatchCorr;    // consider only latch outputs
     int              fConstCorr;    // consider only constants
     int              fUseRings;     // use rings

src/proof/cec/cecCorr.c

@@ -756,6 +756,21 @@ void Cec_ManRefinedClassPrintStats( Gia_Man_t * p, Vec_Str_t * vStatus, int iIte
     Abc_Print( 1, "%c  ", Gia_ObjIsConst( p, Gia_ObjFaninId0p(p, Gia_ManPo(p, 0)) ) ? '+' : '-' );
     Abc_PrintTime( 1, "T", Time );
 }
+int Cec_ManCountLits( Gia_Man_t * p )
+{ 
+    int i, CounterX = 0, Counter0 = 0, Counter = 0;
+    for ( i = 1; i < Gia_ManObjNum(p); i++ )
+    {
+        if ( Gia_ObjIsNone(p, i) )
+            CounterX++;
+        else if ( Gia_ObjIsConst(p, i) )
+            Counter0++;
+        else if ( Gia_ObjIsHead(p, i) )
+            Counter++;
+    }
+    CounterX -= Gia_ManCoNum(p);
+    return Gia_ManCiNum(p) + Gia_ManAndNum(p) - Counter - CounterX;
+}
 
 /**Function*************************************************************
 
@@ -777,7 +792,7 @@ void Cec_ManLSCorrespondenceBmc( Gia_Man_t * pAig, Cec_ParCor_t * pPars, int nPr
     Vec_Int_t * vCexStore;
     Cec_ManSim_t * pSim;
     Gia_Man_t * pSrm;
-    int fChanges, RetValue;
+    int fChanges, RetValue, i;
     // prepare simulation manager
     Cec_ManSimSetDefaultParams( pParsSim );
     pParsSim->nWords     = pPars->nWords;
@@ -791,7 +806,7 @@ void Cec_ManLSCorrespondenceBmc( Gia_Man_t * pAig, Cec_ParCor_t * pPars, int nPr
     pParsSat->nBTLimit = pPars->nBTLimit;
     pParsSat->fVerbose = pPars->fVerbose;
     fChanges = 1;
-    while ( fChanges )
+    for ( i = 0; fChanges && (!pPars->nLimitMax || i < pPars->nLimitMax); i++ )
     {
         abctime clkBmc = Abc_Clock();
         fChanges = 0;
@@ -918,7 +933,7 @@ int Cec_ManLSCorrespondenceClasses( Gia_Man_t * pAig, Cec_ParCor_t * pPars )
     Cec_ParSat_t ParsSat, * pParsSat = &ParsSat;
     Cec_ManSim_t * pSim;
     Gia_Man_t * pSrm;
-    int r, RetValue;
+    int r, RetValue, nPrev[4] = {0};
     abctime clkTotal = Abc_Clock();
     abctime clkSat = 0, clkSim = 0, clkSrm = 0;
     abctime clk2, clk = Abc_Clock();
@@ -1031,6 +1046,21 @@ int Cec_ManLSCorrespondenceClasses( Gia_Man_t * pAig, Cec_ParCor_t * pPars )
             Cec_ManSimStop( pSim );
             return 0;
         }
+        if ( pPars->nLimitMax )
+        {
+            int nCur = Cec_ManCountLits(pAig);
+            if ( r > 4 && nPrev[0] - nCur <= 4*pPars->nLimitMax )
+            {
+                printf( "Iterative refinement is stopped after iteration %d\n", r );
+                printf( "because refinement does not proceed quickly.\n" );
+                Cec_ManSimStop( pSim );
+                return 0;
+            }
+            nPrev[0] = nPrev[1];
+            nPrev[1] = nPrev[2];
+            nPrev[2] = nPrev[3];
+            nPrev[3] = nCur;
+        }
     }
     if ( pPars->fVerbose )
         Cec_ManRefinedClassPrintStats( pAig, NULL, r+1, Abc_Clock() - clk );

src/proof/ssw/ssw.h

@@ -55,6 +55,7 @@ struct Ssw_Pars_t_
     int              nResimDelta;   // the number of nodes to resimulate
     int              nStepsMax;     // (scorr only) the max number of induction steps
     int              TimeLimit;     // time out in seconds
+    int              nLimitMax;     // the limit on the number of iterations
     int              fPolarFlip;    // uses polarity adjustment
     int              fLatchCorr;    // perform register correspondence
     int              fConstCorr;    // perform constant correspondence

src/proof/ssw/sswCore.c

@@ -236,7 +236,7 @@ Aig_Man_t * Ssw_SignalCorrespondenceRefine( Ssw_Man_t * p )
 {
     int nSatProof, nSatCallsSat, nRecycles, nSatFailsReal, nUniques;
     Aig_Man_t * pAigNew;
-    int RetValue, nIter = -1;
+    int RetValue, nIter = -1, nPrev[4] = {0};
     abctime clk, clkTotal = Abc_Clock();
     // get the starting stats
     p->nLitsBeg  = Ssw_ClassesLitNum( p->ppClasses );
@@ -352,7 +352,7 @@ clk = Abc_Clock();
             {
                 printf( "Iterative refinement is stopped after iteration %d\n", nIter );
                 printf( "because the property output is no longer a candidate constant.\n" );
-                // prepare to quite
+                // prepare to quit
                 p->nLitsEnd  = p->nLitsBeg;
                 p->nNodesEnd = p->nNodesBeg;
                 p->nRegsEnd  = p->nRegsBeg;
@@ -381,6 +381,27 @@ clk = Abc_Clock();
             break;
         if ( p->pPars->pFunc )
             ((int (*)(void *))p->pPars->pFunc)( p->pPars->pData );
+        if ( p->pPars->nLimitMax )
+        {
+            int nCur = Ssw_ClassesCand1Num(p->ppClasses);
+            if ( nIter > 4 && nPrev[0] - nCur <= 4*p->pPars->nLimitMax )
+            {
+                printf( "Iterative refinement is stopped after iteration %d\n", nIter );
+                printf( "because the refinment is very slow.\n" );
+                // prepare to quit
+                p->nLitsEnd  = p->nLitsBeg;
+                p->nNodesEnd = p->nNodesBeg;
+                p->nRegsEnd  = p->nRegsBeg;
+                // cleanup
+                Aig_ManSetPhase( p->pAig );
+                Aig_ManCleanMarkB( p->pAig );
+                return Aig_ManDupSimple( p->pAig );
+            }
+            nPrev[0] = nPrev[1];
+            nPrev[1] = nPrev[2];
+            nPrev[2] = nPrev[3];
+            nPrev[3] = nCur;
+        }
     }
 
 finalize: