Adding CEC command &splitprove.

src/base/abci/abc.c

@@ -32876,10 +32876,10 @@ usage:
 ***********************************************************************/
 int Abc_CommandAbc9SplitProve( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
-    extern Gia_Man_t * Cec_GiaSplitTest( Gia_Man_t * p, int nTimeOut, int nIterMax, int fVerbose );
-    int c, nTimeOut = 1, nIterMax = 0, fVerbose = 0;
+    extern Gia_Man_t * Cec_GiaSplitTest( Gia_Man_t * p, int nTimeOut, int nIterMax, int LookAhead, int fVerbose );
+    int c, nTimeOut = 1, nIterMax = 0, LookAhead = 1, fVerbose = 0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "TIvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "TILvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -32905,6 +32905,20 @@ int Abc_CommandAbc9SplitProve( Abc_Frame_t * pAbc, int argc, char ** argv )
             if ( nIterMax < 0 )
                 goto usage;
             break;
+        case 'L':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-L\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            LookAhead = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( LookAhead <= 0 || LookAhead > 100 )
+            {
+                Abc_Print( -1, "Look-ahead value (\"-L <num>\") should be between 1 and 100.\n", LookAhead );
+                goto usage;
+            }
+            break;
         case 'v':
             fVerbose ^= 1;
             break;
@@ -32924,14 +32938,15 @@ int Abc_CommandAbc9SplitProve( Abc_Frame_t * pAbc, int argc, char ** argv )
         Abc_Print( -1, "Abc_CommandAbc9SplitProve(): The problem is sequential.\n" );
         return 1;
     }
-    Cec_GiaSplitTest( pAbc->pGia, nTimeOut, nIterMax, fVerbose );
+    Cec_GiaSplitTest( pAbc->pGia, nTimeOut, nIterMax, LookAhead, fVerbose );
     return 0;
 
 usage:
-    Abc_Print( -2, "usage: &splitprove [-TI num] [-vh]\n" );
+    Abc_Print( -2, "usage: &splitprove [-TIL num] [-vh]\n" );
     Abc_Print( -2, "\t         proves CEC problem by case-splitting\n" );
     Abc_Print( -2, "\t-T num : runtime limit in seconds per subproblem [default = %d]\n",     nTimeOut );
     Abc_Print( -2, "\t-I num : the max number of iterations (0 = infinity) [default = %d]\n", nIterMax );
+    Abc_Print( -2, "\t-L num : maximum look-ahead during cofactoring [default = %d]\n",       LookAhead );
     Abc_Print( -2, "\t-v     : toggle printing verbose information [default = %s]\n",         fVerbose? "yes": "no" );
     Abc_Print( -2, "\t-h     : print the command usage\n");
     return 1;

src/proof/cec/cecSplit.c

@@ -204,12 +204,14 @@ Gia_Man_t * Gia_PermuteSpecial( Gia_Man_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Gia_SplitCofVar2( Gia_Man_t * p )
+int Gia_SplitCofVar2( Gia_Man_t * p, int LookAhead )
 {
+    abctime clk = Abc_Clock();
     Gia_Man_t * pPart;
     int * pOrder = Gia_PermuteSpecialOrder( p );
     int Cost0, Cost1, CostBest = ABC_INFINITY;
-    int i, iBest = -1, LookAhead = 10;
+    int i, iBest = -1;
+    LookAhead = Abc_MinInt( LookAhead, Gia_ManPiNum(p) );
     for ( i = 0; i < LookAhead; i++ )
     {
         pPart = Gia_ManDupCofactor( p, pOrder[i], 0 );
@@ -222,9 +224,14 @@ int Gia_SplitCofVar2( Gia_Man_t * p )
 
         if ( CostBest > Cost0 + Cost1 )
             CostBest = Cost0 + Cost1, iBest = pOrder[i];
+
+//        printf( "%2d : Var = %4d  Refs = %3d  %6d %6d -> %6d\n", 
+//            i, pOrder[i], Gia_ObjRefNum(p, Gia_ManPi(p, pOrder[i])), 
+//            Cost0, Cost1, Cost0+Cost1 );
     }
     ABC_FREE( pOrder );
     assert( iBest >= 0 );
+//    Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
     return iBest;
 }
 
@@ -359,7 +366,7 @@ void Cec_GiaSplitPrintRefs( Gia_Man_t * p )
   SeeAlso     []
 
 ***********************************************************************/
-int Cec_GiaSplitTest( Gia_Man_t * p, int nTimeOut, int nIterMax, int fVerbose )
+int Cec_GiaSplitTest( Gia_Man_t * p, int nTimeOut, int nIterMax, int LookAhead, int fVerbose )
 {
     abctime clk, clkTotal = Abc_Clock();
     Gia_Man_t * pPart0, * pPart1, * pLast;
@@ -387,7 +394,7 @@ int Cec_GiaSplitTest( Gia_Man_t * p, int nTimeOut, int nIterMax, int fVerbose )
             pLast = (Gia_Man_t *)Vec_PtrPop( vStack );
             // determine cofactoring variable
             Depth = Vec_IntSize(pLast->vCofVars);
-            iVar = Gia_SplitCofVar2( pLast );
+            iVar = Gia_SplitCofVar2( pLast, LookAhead );
             // cofactor
             pPart0 = Gia_ManDupCofactor( pLast, iVar, 0 );
             // create variable