Detection of threshold functions.

2 files changed, 100 insertions, 53 deletions

diff --git a/src/misc/util/utilIsop.c b/src/misc/util/utilIsop.c
index f42dcabe..a62fc84d 100644
--- a/src/misc/util/utilIsop.c
+++ b/src/misc/util/utilIsop.c
@@ -95,47 +95,6 @@ static inline void Abc_IsopAddLits( int * pCover, int nCost0, int nCost1, int Va
     for ( c = 0; c < nCost1; c++ )
         pCover[nCost0+c] |= (1 << Abc_Var2Lit(Var,1));
 }
-int Abc_Isop6Cover2( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim, int * pCover )
-{
-    word uOn0, uOn1, uOnDc0, uOnDc1, uRes0, uRes1, uRes2;
-    int Var, nCost0, nCost1, nCost2;
-    assert( nVars <= 6 );
-    assert( (uOn & ~uOnDc) == 0 );
-    if ( uOn == 0 )
-    {
-        pRes[0] = 0;
-        return 0;
-    }
-    if ( uOnDc == ~(word)0 )
-    {
-        pRes[0] = ~(word)0;
-        if ( pCover ) pCover[0] = 0;
-        return (1 << 16);
-    }
-    assert( nVars > 0 );
-    // find the topmost var
-    for ( Var = nVars-1; Var >= 0; Var-- )
-        if ( Abc_Tt6HasVar( uOn, Var ) || Abc_Tt6HasVar( uOnDc, Var ) )
-             break;
-    assert( Var >= 0 );
-    // cofactor
-    uOn0   = Abc_Tt6Cofactor0( uOn,   Var );
-    uOn1   = Abc_Tt6Cofactor1( uOn  , Var );
-    uOnDc0 = Abc_Tt6Cofactor0( uOnDc, Var );
-    uOnDc1 = Abc_Tt6Cofactor1( uOnDc, Var );
-    // solve for cofactors
-    nCost0 = Abc_Isop6Cover2( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
-    if ( nCost0 >= nCostLim ) return nCostLim;
-    nCost1 = Abc_Isop6Cover2( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
-    if ( nCost0 + nCost1 >= nCostLim ) return nCostLim;
-    nCost2 = Abc_Isop6Cover2( (uOn0 & ~uRes0) | (uOn1 & ~uRes1), uOnDc0 & uOnDc1, &uRes2, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) + (nCost1 >> 16) : NULL );
-    if ( nCost0 + nCost1 + nCost2 >= nCostLim ) return nCostLim;
-    // derive the final truth table
-    *pRes = uRes2 | (uRes0 & s_Truths6Neg[Var]) | (uRes1 & s_Truths6[Var]);
-    assert( (uOn & ~*pRes) == 0 && (*pRes & ~uOnDc) == 0 );
-    Abc_IsopAddLits( pCover, nCost0, nCost1, Var );
-    return nCost0 + nCost1 + nCost2 + (nCost0 >> 16) + (nCost1 >> 16);
-}
 int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim, int * pCover )
 {
     word uOn0, uOn1, uOnDc0, uOnDc1, uRes0, uRes1, uRes2;
@@ -164,13 +123,10 @@ int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim,
     uOn1   = Abc_Tt6Cofactor1( uOn  , Var );
     uOnDc0 = Abc_Tt6Cofactor0( uOnDc, Var );
     uOnDc1 = Abc_Tt6Cofactor1( uOnDc, Var );
-//R0 = bsop(L0&~(U1 | (L1 &  ~U0)),U0,new_varbs)
     // solve for cofactors
-//    nCost0 = Abc_Isop6Cover( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
-    nCost0 = Abc_Isop6Cover( uOn0 & ~(uOnDc1 | (uOn1 & ~uOnDc0)), uOnDc0, &uRes0, Var, nCostLim, pCover );
+    nCost0 = Abc_Isop6Cover( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
     if ( nCost0 >= nCostLim ) return nCostLim;
-//    nCost1 = Abc_Isop6Cover( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
-    nCost1 = Abc_Isop6Cover( uOn1 & ~(uOnDc0 | (uOn0 & ~uOnDc1)), uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
+    nCost1 = Abc_Isop6Cover( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
     if ( nCost0 + nCost1 >= nCostLim ) return nCostLim;
     nCost2 = Abc_Isop6Cover( (uOn0 & ~uRes0) | (uOn1 & ~uRes1), uOnDc0 & uOnDc1, &uRes2, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) + (nCost1 >> 16) : NULL );
     if ( nCost0 + nCost1 + nCost2 >= nCostLim ) return nCostLim;
@@ -180,7 +136,6 @@ int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim,
     Abc_IsopAddLits( pCover, nCost0, nCost1, Var );
     return nCost0 + nCost1 + nCost2 + (nCost0 >> 16) + (nCost1 >> 16);
 }
-
 int Abc_Isop7Cover( word * pOn, word * pOnDc, word * pRes, int * pCover, int nCostLim )
 {
     word uOn0, uOn1, uOn2, uOnDc2, uRes0, uRes1, uRes2;
@@ -622,13 +577,11 @@ int Abc_Isop( word * pFunc, int nVars, int Type, int nCubeLim, Vec_Int_t * vCove
 ***********************************************************************/
 int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
 {
-    int fVerbose = 1;
+    int Cost, fVerbose = 0;
     word pRes[1024];
-    int Cost;
 //    if ( fVerbose )
 //    Dau_DsdPrintFromTruth( pFunc, nVars ), printf( "         " );
 
-
     Cost = Abc_IsopCheck( pFunc, pFunc, pRes, nVars, ABC_INFINITY, Vec_IntArray(vCover) );
     vCover->nSize = Cost >> 16;
     assert( vCover->nSize <= vCover->nCap );
@@ -646,7 +599,7 @@ int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
     printf( "%5d(%5d) ", Cost >> 16, Cost & 0xFFFF );
     Abc_IsopVerify( pFunc, nVars, pRes, vCover, 0, 1 );
 
-/*
+
     Cost = Abc_EsopCheck( pFunc, nVars, ABC_INFINITY, Vec_IntArray(vCover) );
     vCover->nSize = Cost >> 16;
     assert( vCover->nSize <= vCover->nCap );
@@ -663,12 +616,11 @@ int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
     if ( fVerbose )
     printf( "%5d(%5d)  ", Cost >> 16, Cost & 0xFFFF );
     Abc_IsopVerify( pFunc, nVars, pRes, vCover, 1, 1 );
-*/
+
 
     if ( fVerbose )
     printf( "\n" );
 //Kit_TruthIsopPrintCover( vCover, nVars, 0 );
-
     return 1; 
 }
 
diff --git a/src/misc/util/utilTruth.h b/src/misc/util/utilTruth.h
index 1416034d..0b52b3f4 100644
--- a/src/misc/util/utilTruth.h
+++ b/src/misc/util/utilTruth.h
@@ -1597,6 +1597,101 @@ static inline void Abc_TtReverseBits( word * pTruth, int nVars )
 
 /**Function*************************************************************
 
+  Synopsis    [Checks unateness of a function.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Abc_Tt6PosVar( word t, int iVar )
+{
+    return ((t >> (1<<iVar)) & t & s_Truths6Neg[iVar]) == (t & s_Truths6Neg[iVar]);
+}
+static inline int Abc_Tt6NegVar( word t, int iVar )
+{
+    return ((t << (1<<iVar)) & t & s_Truths6[iVar]) == (t & s_Truths6[iVar]);
+}
+static inline int Abc_TtPosVar( word * t, int nVars, int iVar )
+{
+    assert( iVar < nVars );
+    if ( nVars <= 6 )
+        return Abc_Tt6PosVar( t[0], iVar );
+    if ( iVar < 6 )
+    {
+        int i, Shift = (1 << iVar);
+        int nWords = Abc_TtWordNum( nVars );
+        for ( i = 0; i < nWords; i++ )
+            if ( ((t[i] >> Shift) & t[i] & s_Truths6Neg[iVar]) != (t[i] & s_Truths6Neg[iVar]) )
+                return 0;
+        return 1;
+    }
+    else
+    {
+        int i, Step = (1 << (iVar - 6));
+        word * tLimit = t + Abc_TtWordNum( nVars );
+        for ( ; t < tLimit; t += 2*Step )
+            for ( i = 0; i < Step; i++ )
+                if ( t[i] != (t[i] & t[Step+i]) )
+                    return 0;
+        return 1;
+    }
+}
+static inline int Abc_TtNegVar( word * t, int nVars, int iVar )
+{
+    assert( iVar < nVars );
+    if ( nVars <= 6 )
+        return Abc_Tt6NegVar( t[0], iVar );
+    if ( iVar < 6 )
+    {
+        int i, Shift = (1 << iVar);
+        int nWords = Abc_TtWordNum( nVars );
+        for ( i = 0; i < nWords; i++ )
+            if ( ((t[i] << Shift) & t[i] & s_Truths6[iVar]) != (t[i] & s_Truths6[iVar]) )
+                return 0;
+        return 1;
+    }
+    else
+    {
+        int i, Step = (1 << (iVar - 6));
+        word * tLimit = t + Abc_TtWordNum( nVars );
+        for ( ; t < tLimit; t += 2*Step )
+            for ( i = 0; i < Step; i++ )
+                if ( (t[i] & t[Step+i]) != t[Step+i] )
+                    return 0;
+        return 1;
+    }
+}
+static inline int Abc_TtIsUnate( word * t, int nVars )
+{
+    int i;
+    for ( i = 0; i < nVars; i++ )
+        if ( !Abc_TtNegVar(t, nVars, i) && !Abc_TtPosVar(t, nVars, i) )
+            return 0;
+    return 1;
+}
+static inline int Abc_TtIsPosUnate( word * t, int nVars )
+{
+    int i;
+    for ( i = 0; i < nVars; i++ )
+        if ( !Abc_TtPosVar(t, nVars, i) )
+            return 0;
+    return 1;
+}
+static inline void Abc_TtMakePosUnate( word * t, int nVars )
+{
+    int i, nWords = Abc_TtWordNum(nVars);
+    for ( i = 0; i < nVars; i++ )
+        if ( Abc_TtNegVar(t, nVars, i) )
+            Abc_TtFlip( t, nWords, i );
+        else assert( Abc_TtPosVar(t, nVars, i) );
+}
+
+
+/**Function*************************************************************
+
   Synopsis    [Computes ISOP for 6 variables or less.]
 
   Description []