Logic restructuring after mapping.

1 files changed, 269 insertions, 41 deletions

diff --git a/src/base/acb/acbPush.c b/src/base/acb/acbPush.c
index 08edc4d1..7ede912f 100644
--- a/src/base/acb/acbPush.c
+++ b/src/base/acb/acbPush.c
@@ -33,7 +33,105 @@ ABC_NAMESPACE_IMPL_START
 
 /**Function*************************************************************
 
-  Synopsis    [Check if the node can have its logic pushed.]
+  Synopsis    [Pushing logic to the fanout.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Acb_ObjPushToFanout( Acb_Ntk_t * p, int iObj, int iFaninIndex, int iFanout )
+{
+    word c0, uTruthObjNew, uTruthObj = Acb_ObjTruth( p, iObj ), Gate;
+    word c1, uTruthFanNew, uTruthFan = Acb_ObjTruth( p, iFanout );
+    int DecType = Abc_TtCheckOutAnd( uTruthObj, iFaninIndex, &uTruthObjNew );
+    int iFanin = Acb_ObjFanin( p, iObj, iFaninIndex );
+    int iFanoutObjIndex = Acb_ObjWhatFanin( p, iFanout, iObj );
+    int iFanoutFaninIndex = Acb_ObjWhatFanin( p, iFanout, iFanin );
+    if ( iFanoutFaninIndex == -1 )
+        iFanoutFaninIndex = Acb_ObjFaninNum(p, iFanout); 
+    assert( !Acb_ObjIsCio(p, iObj) );
+    assert( !Acb_ObjIsCio(p, iFanout) );
+    assert( iFanoutFaninIndex >= 0 );
+    assert( iFaninIndex < Acb_ObjFaninNum(p, iObj) );
+    assert( Acb_ObjFanoutNum(p, iObj) == 1 );
+    // compute new function of the fanout
+    c0 = Abc_Tt6Cofactor0( uTruthFan, iFanoutObjIndex );
+    c1 = Abc_Tt6Cofactor1( uTruthFan, iFanoutObjIndex );
+    if ( DecType == 0 ) //  F = i * G
+        Gate =  s_Truths6[iFanoutFaninIndex] & s_Truths6[iFanoutObjIndex];
+    else if ( DecType == 1 ) //  F = ~i * G
+        Gate = ~s_Truths6[iFanoutFaninIndex] & s_Truths6[iFanoutObjIndex];
+    else if ( DecType == 2 ) //  F = ~i + G
+        Gate = ~s_Truths6[iFanoutFaninIndex] | s_Truths6[iFanoutObjIndex];
+    else if ( DecType == 3 ) //  F = i + G
+        Gate =  s_Truths6[iFanoutFaninIndex] | s_Truths6[iFanoutObjIndex];
+    else if ( DecType == 4 ) //  F = i # G
+        Gate =  s_Truths6[iFanoutFaninIndex] ^ s_Truths6[iFanoutObjIndex];
+    else assert( 0 );
+    uTruthFanNew = (~Gate & c0) | (Gate & c1);
+    // update functions
+    Vec_WrdWriteEntry( &p->vObjTruth, iObj, Abc_Tt6RemoveVar(uTruthObjNew, iFaninIndex) );
+    Vec_WrdWriteEntry( &p->vObjTruth, iFanout, uTruthFanNew );
+    // update fanins
+    Acb_ObjRemoveFaninFanoutOne( p, iObj, iFanin );
+    if ( iFanoutFaninIndex == Acb_ObjFaninNum(p, iFanout) ) // adding new
+        Acb_ObjAddFaninFanoutOne( p, iFanout, iFanin );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Pushing logic to the fanin.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Acb_ObjPushToFanin( Acb_Ntk_t * p, int iObj, int iFaninIndex2, int iFanin )
+{
+    word uTruthObjNew, uTruthObj = Acb_ObjTruth( p, iObj );
+    word uTruthFanNew, uTruthFan = Acb_ObjTruth( p, iFanin );
+    int iFaninIndex = Acb_ObjWhatFanin( p, iObj, iFanin );
+    int DecType = Abc_TtCheckDsdAnd( uTruthObj, iFaninIndex, iFaninIndex2, &uTruthObjNew );
+    int iFanin2 = Acb_ObjFanin( p, iObj, iFaninIndex2 );
+    int iFaninFaninIndex = Acb_ObjWhatFanin( p, iFanin, iFanin2 );
+    if ( iFaninFaninIndex == -1 )
+        iFaninFaninIndex = Acb_ObjFaninNum(p, iFanin); 
+    assert( !Acb_ObjIsCio(p, iObj) );
+    assert( !Acb_ObjIsCio(p, iFanin) );
+    assert( iFaninIndex  < Acb_ObjFaninNum(p, iObj) );
+    assert( iFaninIndex2 < Acb_ObjFaninNum(p, iObj) );
+    assert( iFaninIndex != iFaninIndex2 );
+    assert( Acb_ObjFanoutNum(p, iFanin) == 1 );
+    // compute new function of the fanout
+    if ( DecType == 0 )      //  i *  j
+        uTruthFanNew =  uTruthFan &  s_Truths6[iFaninFaninIndex];
+    else if ( DecType == 1 ) //  i * !j
+        uTruthFanNew = ~uTruthFan &  s_Truths6[iFaninFaninIndex];
+    else if ( DecType == 2 ) // !i *  j
+        uTruthFanNew =  uTruthFan & ~s_Truths6[iFaninFaninIndex];
+    else if ( DecType == 3 ) // !i * !j
+        uTruthFanNew = ~uTruthFan & ~s_Truths6[iFaninFaninIndex];
+    else if ( DecType == 4 ) //  i #  j
+        uTruthFanNew =  uTruthFan ^  s_Truths6[iFaninFaninIndex];
+    else assert( 0 );
+    // update functions
+    Vec_WrdWriteEntry( &p->vObjTruth, iObj, Abc_Tt6RemoveVar(uTruthObjNew, iFaninIndex2) );
+    Vec_WrdWriteEntry( &p->vObjTruth, iFanin, uTruthFanNew );
+    // update fanins
+    Acb_ObjRemoveFaninFanoutOne( p, iObj, iFanin2 );
+    if ( iFaninFaninIndex == Acb_ObjFaninNum(p, iFanin) ) // adding new
+        Acb_ObjAddFaninFanoutOne( p, iFanin, iFanin2 );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Removing constants, buffers, duplicated fanins.]
 
   Description []
                
@@ -42,50 +140,155 @@ ABC_NAMESPACE_IMPL_START
   SeeAlso     []
 
 ***********************************************************************/
-int Acb_ObjCheckFaninDsd( Acb_Ntk_t * p, int iObj, int iFanIndex )
+static inline int Acb_ObjFindNodeFanout( Acb_Ntk_t * p, int iObj )
+{
+    int i, iFanout;
+    Acb_ObjForEachFanout( p, iObj, iFanout, i )
+        if ( !Acb_ObjIsCio(p, iFanout) )
+            return iFanout;
+    return -1;
+}
+int Acb_ObjSuppMin_int( Acb_Ntk_t * p, int iObj )
 {
     int k, iFanin, * pFanins;
+    word uTruth = Acb_ObjTruth( p, iObj );
     Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
-        if ( Abc_TtCheckDsdAnd(Acb_ObjTruth(p, iObj), iFanIndex, k, NULL) >= 0 )
-            return 1;
+    {
+        if ( Abc_Tt6HasVar(uTruth, k) )
+            continue;
+        Acb_ObjDeleteFaninIndex( p, iObj, k );
+        Vec_IntRemove( Vec_WecEntry(&p->vFanouts, iFanin), iObj );
+        Vec_WrdWriteEntry( &p->vObjTruth, iObj, Abc_Tt6RemoveVar(uTruth, k) );
+        return 1;
+    }
     return 0;
 }
-int Acb_ObjCountFaninAbsorb( Acb_Ntk_t * p, int iObj, int iFanin, int iFanIndex, int nLutSize )
+void Acb_ObjSuppMin( Acb_Ntk_t * p, int iObj )
 {
-    if ( Acb_ObjSetTravIdCur(p, iFanin) )
-        return 0;
-    if ( Acb_ObjIsCi(p, iFanin) )
-        return 0;
-    if ( Acb_ObjFanoutNum(p, iFanin) > 1 )
-        return 0;
-    if ( !Acb_ObjCheckFaninDsd(p, iObj, iFanIndex) ) 
-        return 0;
-    if ( Acb_ObjFaninNum(p, iFanin) == nLutSize )
-        return 0;
-    return 1;
+    while ( Acb_ObjSuppMin_int(p, iObj) );
 }
-int Acb_NtkObjPushEstimate( Acb_Ntk_t * p, int iObj, int nLutSize )
+void Acb_ObjRemoveDup( Acb_Ntk_t * p, int iObj, int i, int j )
 {
-    int k, iFanin, * pFanins;
-    int Count = Acb_ObjFaninNum(p, iObj);
-    Acb_NtkIncTravId( p );
-    Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
+    word c00, c11, uTruthNew, uTruth = Acb_ObjTruth( p, iObj );
+    assert( !Acb_ObjIsCio(p, iObj) );
+    assert( Acb_ObjFanin(p, iObj, i) == Acb_ObjFanin(p, iObj, j) );
+    c00 = Abc_Tt6Cofactor0( Abc_Tt6Cofactor0(uTruth, i), j );
+    c11 = Abc_Tt6Cofactor1( Abc_Tt6Cofactor1(uTruth, i), j );
+    uTruthNew = (~s_Truths6[i] & c00) | (s_Truths6[i] & c11);
+    Vec_WrdWriteEntry( &p->vObjTruth, iObj, Abc_Tt6RemoveVar(uTruthNew, j) );
+    Acb_ObjDeleteFaninIndex( p, iObj, j );
+    Vec_IntRemove( Vec_WecEntry(&p->vFanouts, iObj), Acb_ObjFanin(p, iObj, j) );
+    Acb_ObjSuppMin( p, iObj );
+}
+int Acb_ObjRemoveDupFanins_int( Acb_Ntk_t * p, int iObj )
+{
+    int i, k, * pFanins = Acb_ObjFanins( p, iObj );
+    for ( i = 0; i < pFanins[0]; i++ )
+    for ( k = i+1; k < pFanins[0]; k++ )
     {
-        Count -= Acb_ObjCountFaninAbsorb( p, iObj, iFanin, k, nLutSize );
-        if ( Count <= 0 )
-            return 1;
+        if ( pFanins[1+i] != pFanins[1+k] )
+            continue;
+        Acb_ObjRemoveDup( p, iObj, i, k );
+        return 1;
     }
-    if ( Acb_ObjFanoutNum(p, iObj) > 1 )
-        return 0;
+    return 0;
+}
+void Acb_ObjRemoveDupFanins( Acb_Ntk_t * p, int iObj )
+{
+    assert( !Acb_ObjIsCio(p, iObj) );
+    while ( Acb_ObjRemoveDupFanins_int(p, iObj) );
+}
+void Acb_ObjRemoveConst( Acb_Ntk_t * p, int iObj )
+{
+    int iFanout;
+    word uTruth = Acb_ObjTruth( p, iObj );
+    assert( !Acb_ObjIsCio(p, iObj) );
+    assert( Acb_ObjFaninNum(p, iObj) == 0 );
+    assert( uTruth == 0 || ~uTruth == 0 );
+    while ( (iFanout = Acb_ObjFindNodeFanout(p, iObj)) >= 0 )
+    {
+        int iObjIndex = Acb_ObjWhatFanin( p, iFanout, iObj );
+        word uTruthF = Acb_ObjTruth( p, iFanout );
+        Acb_ObjRemoveFaninFanoutOne( p, iFanout, iObj );
+        uTruthF = (uTruth & 1) ? Abc_Tt6Cofactor1(uTruthF, iObjIndex) : Abc_Tt6Cofactor0(uTruthF, iObjIndex);
+        Vec_WrdWriteEntry( &p->vObjTruth, iFanout, Abc_Tt6RemoveVar(uTruthF, iObjIndex) );
+        Acb_ObjSuppMin( p, iFanout );
+    }
+    if ( Acb_ObjFanoutNum(p, iObj) == 0 )
+        Acb_ObjCleanType( p, iObj );
+}
+void Acb_ObjRemoveBufInv( Acb_Ntk_t * p, int iObj )
+{
+    int iFanout;
+    word uTruth = Acb_ObjTruth( p, iObj );
+    assert( !Acb_ObjIsCio(p, iObj) );
+    assert( Acb_ObjFaninNum(p, iObj) == 1 );
+    assert( uTruth == s_Truths6[0] || ~uTruth == s_Truths6[0] );
+    while ( (iFanout = Acb_ObjFindNodeFanout(p, iObj)) >= 0 )
+    {
+        int iFanin = Acb_ObjFanin( p, iObj, 0 );
+        int iObjIndex = Acb_ObjWhatFanin( p, iFanout, iObj );
+        Acb_ObjPatchFanin( p, iFanout, iObj, iFanin );
+        if ( uTruth & 1 ) // inv
+        {
+            word uTruthF = Acb_ObjTruth( p, iFanout );
+            Vec_WrdWriteEntry( &p->vObjTruth, iFanout, Abc_Tt6Flip(uTruthF, iObjIndex) );
+        }
+        Acb_ObjRemoveDupFanins( p, iFanout );
+    }
+    while ( (uTruth & 1) == 0 && Acb_ObjFanoutNum(p, iObj) > 0 )
+    {
+        int iFanin = Acb_ObjFanin( p, iObj, 0 );
+        int iFanout = Acb_ObjFanout( p, iObj, 0 );
+        assert( Acb_ObjIsCo(p, iFanout) );
+        Acb_ObjPatchFanin( p, iFanout, iObj, iFanin );
+    }
+    if ( Acb_ObjFanoutNum(p, iObj) == 0 )
+    {
+        Acb_ObjRemoveFaninFanout( p, iObj );
+        Acb_ObjRemoveFanins( p, iObj );
+        Acb_ObjCleanType( p, iObj );
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Check if the node can have its logic pushed.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Acb_ObjFindPushableIndex( Acb_Ntk_t * p, int iObj, int iFanIndex )
+{
+    int k, iFanin, * pFanins;
     Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
-        if ( Abc_TtCheckOutAnd(Acb_ObjTruth(p, iObj), k, NULL) )
-            break;
-    if ( k == Acb_ObjFaninNum(p, iFanin) )
-        return 0;
-    iFanin = Vec_IntEntry( Acb_ObjFanout(p, iObj), 0 );
-    if ( Acb_ObjFaninNum(p, iFanin) == nLutSize )
+        if ( k != iFanIndex && Abc_TtCheckDsdAnd(Acb_ObjTruth(p, iObj), k, iFanIndex, NULL) >= 0 )
+            return k;
+    return -1;
+}
+int Acb_ObjPushToFanins( Acb_Ntk_t * p, int iObj, int nLutSize )
+{
+    int k, k2, iFanin, * pFanins;
+    if ( Acb_ObjFaninNum(p, iObj) < 2 )
         return 0;
-    return 1;
+    Acb_ObjForEachFaninFast( p, iObj, pFanins, iFanin, k )
+    {
+        if ( Acb_ObjIsCi(p, iFanin) )
+            continue;
+        if ( Acb_ObjFanoutNum(p, iFanin) > 1 )
+            continue;
+        if ( Acb_ObjFaninNum(p, iFanin) == nLutSize )
+            continue;
+        if ( (k2 = Acb_ObjFindPushableIndex(p, iObj, k)) == -1 )
+            continue;
+        Acb_ObjPushToFanin( p, iObj, k2, iFanin );
+        return 1;
+    }
+    return 0;
 }
 
 /**Function*************************************************************
@@ -101,18 +304,43 @@ int Acb_NtkObjPushEstimate( Acb_Ntk_t * p, int iObj, int nLutSize )
 ***********************************************************************/
 void Acb_NtkPushLogic( Acb_Ntk_t * p, int nLutSize, int fVerbose )
 {
-    //Vec_Bit_t * vVisited = Vec_BitStart( Acb_NtkObjNumMax(p) );
-    int n = 0, iObj, nNodes = 0;
+    int n = 0, iObj, nNodes = Acb_NtkNodeNum(p), nPushes = 0;
     Acb_NtkCreateFanout( p );  // fanout data structure
+    Acb_NtkForEachNodeSupp( p, iObj, 0 )
+        Acb_ObjRemoveConst( p, iObj );
+    Acb_NtkForEachNodeSupp( p, iObj, 1 )
+        Acb_ObjRemoveBufInv( p, iObj );
     for ( n = 2; n <= nLutSize; n++ )
-        Acb_NtkForEachNode( p, iObj )
+        Acb_NtkForEachNodeSupp( p, iObj, n )
         {
-            if ( !Acb_NtkObjPushEstimate(p, iObj, nLutSize) )
-                continue;
-            nNodes++;
+            while ( Acb_ObjPushToFanins(p, iObj, nLutSize) )
+                nPushes++;
+            if ( Acb_ObjFaninNum(p, iObj) == 1 )
+                Acb_ObjRemoveBufInv( p, iObj );
         }
-    printf( "Performed optimization at %d nodes.\n", nNodes );
-    //Vec_BitFree( vVisited );
+    printf( "Saved %d nodes after %d pushes.\n", nNodes - Acb_NtkNodeNum(p), nPushes );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Pushing logic to the fanin.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Acb_NtkPushLogic2( Acb_Ntk_t * p, int nLutSize, int fVerbose )
+{
+    int iObj;
+    Acb_NtkCreateFanout( p );  // fanout data structure
+    Acb_NtkForEachObj( p, iObj )
+        if ( !Acb_ObjIsCio(p, iObj) )
+            break;
+    Acb_ObjPushToFanout( p, iObj, Acb_ObjFaninNum(p, iObj)-1, Acb_ObjFanout(p, iObj, 0) );
+//    Acb_ObjPushToFanin( p, Acb_ObjFanout(p, iObj, 0), Acb_ObjFaninNum(p, iObj)-1, iObj );
 }
 
 ////////////////////////////////////////////////////////////////////////