Detecting full-adder chains and putting them into white boxes.

6 files changed, 594 insertions, 94 deletions

diff --git a/abclib.dsp b/abclib.dsp
index 5559b243..6a54f379 100644
--- a/abclib.dsp
+++ b/abclib.dsp
@@ -3815,6 +3815,10 @@ SOURCE=.\src\aig\gia\giaEra2.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\src\aig\gia\giaFadds.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\src\aig\gia\giaFalse.c
 # End Source File
 # Begin Source File
diff --git a/src/aig/gia/gia.h b/src/aig/gia/gia.h
index 683c868a..ad65fcdc 100644
--- a/src/aig/gia/gia.h
+++ b/src/aig/gia/gia.h
@@ -719,6 +719,13 @@ static inline int Gia_ManAppendMux( Gia_Man_t * p, int iCtrl, int iData1, int iD
     int iTemp1 = Gia_ManAppendAnd( p, iCtrl, iData1 );
     return Abc_LitNotCond( Gia_ManAppendAnd( p, Abc_LitNot(iTemp0), Abc_LitNot(iTemp1) ), 1 );
 }
+static inline int Gia_ManAppendMaj( Gia_Man_t * p, int iData0, int iData1, int iData2 )  
+{ 
+    int iTemp0 = Gia_ManAppendOr( p, iData1, iData2 );
+    int iTemp1 = Gia_ManAppendAnd( p, iData0, iTemp0 );
+    int iTemp2 = Gia_ManAppendAnd( p, iData1, iData2 );
+    return Gia_ManAppendOr( p, iTemp1, iTemp2 );
+}
 static inline int Gia_ManAppendXor( Gia_Man_t * p, int iLit0, int iLit1 )  
 { 
     return Gia_ManAppendMux( p, iLit0, Abc_LitNot(iLit1), iLit1 );
diff --git a/src/aig/gia/giaFadds.c b/src/aig/gia/giaFadds.c
index d74eb577..4c2b9481 100644
--- a/src/aig/gia/giaFadds.c
+++ b/src/aig/gia/giaFadds.c
@@ -19,6 +19,8 @@
 ***********************************************************************/
 
 #include "gia.h"
+#include "misc/vec/vecWec.h"
+#include "misc/tim/tim.h"
 
 ABC_NAMESPACE_IMPL_START
 
@@ -27,14 +29,63 @@ ABC_NAMESPACE_IMPL_START
 ///                        DECLARATIONS                              ///
 ////////////////////////////////////////////////////////////////////////
 
+#define Dtc_ForEachCut( pList, pCut, i ) for ( i = 0, pCut = pList + 1; i < pList[0]; i++, pCut += pCut[0] + 1 )
+#define Dtc_ForEachFadd( vFadds, i )     for ( i = 0; i < Vec_IntSize(vFadds)/5; i++ )
+
 ////////////////////////////////////////////////////////////////////////
 ///                     FUNCTION DEFINITIONS                         ///
 ////////////////////////////////////////////////////////////////////////
 
+/**Function*************************************************************
+
+  Synopsis    [Derive GIA with boxes containing adder-chains.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManIllustrateBoxes( Gia_Man_t * p )
+{
+    Tim_Man_t * pManTime = (Tim_Man_t *)p->pManTime;
+    int nBoxes = Tim_ManBoxNum( pManTime );
+    int i, k, curCi, curCo, nBoxIns, nBoxOuts;
+    Gia_Obj_t * pObj;
+    // walk through the boxes
+    curCi = Tim_ManPiNum(pManTime);
+    curCo = 0;
+    for ( i = 0; i < Tim_ManBoxNum(pManTime); i++ )
+    {
+        nBoxIns = Tim_ManBoxInputNum(pManTime, i);
+        nBoxOuts = Tim_ManBoxOutputNum(pManTime, i);
+        printf( "Box %4d  [%d x %d] :   ", i, nBoxIns, nBoxOuts );
+        printf( "Input obj IDs = " );
+        for ( k = 0; k < nBoxIns; k++ )
+        {
+            pObj = Gia_ManCo( p, curCo + k );
+            printf( "%d ", Gia_ObjId(p, pObj) );
+        }
+        printf( "  Output obj IDs = " );
+        for ( k = 0; k < nBoxOuts; k++ )
+        {
+            pObj = Gia_ManCi( p, curCi + k );
+            printf( "%d ", Gia_ObjId(p, pObj) );
+        }
+        curCo += nBoxIns;
+        curCi += nBoxOuts;
+        printf( "\n" );
+    }
+    curCo += Tim_ManPoNum(pManTime);
+    // verify counts
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
+}
 
 /**Function*************************************************************
 
-  Synopsis    []
+  Synopsis    [Detecting FADDs in the AIG.]
 
   Description []
                
@@ -43,7 +94,6 @@ ABC_NAMESPACE_IMPL_START
   SeeAlso     []
 
 ***********************************************************************/
-#define Dtc_ForEachCut( pList, pCut, i ) for ( i = 0, pCut = pList + 1; i < pList[0]; i++, pCut += pCut[0] + 1 )
 int Dtc_ManCutMergeOne( int * pCut0, int * pCut1, int * pCut )
 {
     int i, k;
@@ -108,21 +158,20 @@ void Dtc_ObjCleanTruth_rec( Gia_Obj_t * pObj )
     Dtc_ObjCleanTruth_rec( Gia_ObjFanin0(pObj) );
     Dtc_ObjCleanTruth_rec( Gia_ObjFanin1(pObj) );
 }
-int Dtc_ObjComputeTruth( Gia_Man_t * p, int iObj, int * pCut )
+int Dtc_ObjComputeTruth( Gia_Man_t * p, int iObj, int * pCut, int * pTruth )
 {
     unsigned Truth, Truths[3] = { 0xAA, 0xCC, 0xF0 }; int i;
     for ( i = 1; i <= pCut[0]; i++ )
         Gia_ManObj(p, pCut[i])->Value = Truths[i-1];
     Truth = 0xFF & Dtc_ObjComputeTruth_rec( Gia_ManObj(p, iObj) );
     Dtc_ObjCleanTruth_rec( Gia_ManObj(p, iObj) );
-    if ( Truth == 0x69 || Truth == 0x96 )
+    if ( pTruth ) 
+        *pTruth = Truth;
+    if ( Truth == 0x96 || Truth == 0x69 )
         return 1;
-    if ( Truth == 0x8E || Truth == 0x4D || Truth == 0x2B || Truth == 0xE8 ||
-         Truth == 0x71 || Truth == 0xB2 || Truth == 0xD4 || Truth == 0x17 )
-    {
-//        printf( "%2x ", Truth );
+    if ( Truth == 0xE8 || Truth == 0xD4 || Truth == 0xB2 || Truth == 0x71 ||
+         Truth == 0x17 || Truth == 0x2B || Truth == 0x4D || Truth == 0x8E )
         return 2;
-    }
     return 0;
 }
 void Dtc_ManCutMerge( Gia_Man_t * p, int iObj, int * pList0, int * pList1, Vec_Int_t * vCuts, Vec_Int_t * vCutsXor, Vec_Int_t * vCutsMaj )
@@ -143,7 +192,7 @@ void Dtc_ManCutMerge( Gia_Man_t * p, int iObj, int * pList0, int * pList1, Vec_I
             Vec_IntPush( vCuts, pCut[c] );
         if ( pCut[0] != 3 )
             continue;
-        Type = Dtc_ObjComputeTruth( p, iObj, pCut );
+        Type = Dtc_ObjComputeTruth( p, iObj, pCut, NULL );
         if ( Type == 0 )
             continue;
         vTemp = Type == 1 ? vCutsXor : vCutsMaj;
@@ -152,7 +201,7 @@ void Dtc_ManCutMerge( Gia_Man_t * p, int iObj, int * pList0, int * pList1, Vec_I
         Vec_IntPush( vTemp, iObj );
     }
 }
-void Dtc_ManComputeCuts( Gia_Man_t * p, Vec_Int_t ** pvCutsXor, Vec_Int_t ** pvCutsMaj )
+void Dtc_ManComputeCuts( Gia_Man_t * p, Vec_Int_t ** pvCutsXor, Vec_Int_t ** pvCutsMaj, int fVerbose )
 {
     Gia_Obj_t * pObj; 
     int * pList0, * pList1, i, nCuts = 0;
@@ -178,23 +227,14 @@ void Dtc_ManComputeCuts( Gia_Man_t * p, Vec_Int_t ** pvCutsXor, Vec_Int_t ** pvC
         Vec_IntAppend( vCuts, vTemp );
         nCuts += Vec_IntSize( vTemp );
     }
-    printf( "Nodes = %d.  Cuts = %d.  Cuts/Node = %.2f.  Ints/Node = %.2f.\n", 
-        Gia_ManAndNum(p), nCuts, 1.0*nCuts/Gia_ManAndNum(p), 1.0*Vec_IntSize(vCuts)/Gia_ManAndNum(p) );
+    if ( fVerbose )
+        printf( "Nodes = %d.  Cuts = %d.  Cuts/Node = %.2f.  Ints/Node = %.2f.\n", 
+            Gia_ManAndNum(p), nCuts, 1.0*nCuts/Gia_ManAndNum(p), 1.0*Vec_IntSize(vCuts)/Gia_ManAndNum(p) );
     Vec_IntFree( vTemp );
     Vec_IntFree( vCuts );
     *pvCutsXor = vCutsXor;
     *pvCutsMaj = vCutsMaj;
 }
-int Dtc_ManCompare( int * pCut0, int * pCut1 )
-{
-    if ( pCut0[0] < pCut1[0] ) return -1;
-    if ( pCut0[0] > pCut1[0] ) return  1;
-    if ( pCut0[1] < pCut1[1] ) return -1;
-    if ( pCut0[1] > pCut1[1] ) return  1;
-    if ( pCut0[2] < pCut1[2] ) return -1;
-    if ( pCut0[2] > pCut1[2] ) return  1;
-    return 0;
-}
 Vec_Int_t * Dtc_ManFindCommonCuts( Gia_Man_t * p, Vec_Int_t * vCutsXor, Vec_Int_t * vCutsMaj )
 {
     int * pCuts0 = Vec_IntArray(vCutsXor);
@@ -222,13 +262,13 @@ Vec_Int_t * Dtc_ManFindCommonCuts( Gia_Man_t * p, Vec_Int_t * vCutsXor, Vec_Int_
         else if ( pCuts0[i] > pCuts1[i] )
             pCuts1 += 4;
     }
+    assert( Vec_IntSize(vFadds) % 5 == 0 );
     return vFadds;
 }
 void Dtc_ManPrintFadds( Vec_Int_t * vFadds )
 {
-    int i, nObjs = Vec_IntSize(vFadds)/5;
-    assert( Vec_IntSize(vFadds) % 5 == 0 );
-    for ( i = 0; i < nObjs; i++ )
+    int i;
+    Dtc_ForEachFadd( vFadds, i )
     {
         printf( "%6d : ", i );
         printf( "%6d ", Vec_IntEntry(vFadds, 5*i+0) );
@@ -240,34 +280,213 @@ void Dtc_ManPrintFadds( Vec_Int_t * vFadds )
         printf( "\n" );
     }
 }
-void Dtc_ManSortChains( Gia_Man_t * p, Vec_Int_t * vFadds )
+int Dtc_ManCompare( int * pCut0, int * pCut1 )
 {
-    Vec_Int_t * vMap = Vec_IntStartFull( Gia_ManObjNum(p) );
-    int i, iFadd, Count = 0, nObjs = Vec_IntSize(vFadds)/5;
-    assert( Vec_IntSize(vFadds) % 5 == 0 );
-    for ( i = 0; i < nObjs; i++ )
+    if ( pCut0[0] < pCut1[0] ) return -1;
+    if ( pCut0[0] > pCut1[0] ) return  1;
+    if ( pCut0[1] < pCut1[1] ) return -1;
+    if ( pCut0[1] > pCut1[1] ) return  1;
+    if ( pCut0[2] < pCut1[2] ) return -1;
+    if ( pCut0[2] > pCut1[2] ) return  1;
+    return 0;
+}
+int Dtc_ManCompare2( int * pCut0, int * pCut1 )
+{
+    if ( pCut0[4] < pCut1[4] ) return -1;
+    if ( pCut0[4] > pCut1[4] ) return  1;
+    return 0;
+}
+// returns array of 5-tuples containing inputs/sum/cout of each full adder
+Vec_Int_t * Gia_ManDetectFullAdders( Gia_Man_t * p, int fVerbose )
+{
+    Vec_Int_t * vCutsXor, * vCutsMaj, * vFadds;
+    Dtc_ManComputeCuts( p, &vCutsXor, &vCutsMaj, fVerbose );
+    qsort( Vec_IntArray(vCutsXor), Vec_IntSize(vCutsXor)/4, 16, (int (*)(const void *, const void *))Dtc_ManCompare );
+    qsort( Vec_IntArray(vCutsMaj), Vec_IntSize(vCutsMaj)/4, 16, (int (*)(const void *, const void *))Dtc_ManCompare );
+    vFadds = Dtc_ManFindCommonCuts( p, vCutsXor, vCutsMaj );
+    qsort( Vec_IntArray(vFadds), Vec_IntSize(vFadds)/5, 20, (int (*)(const void *, const void *))Dtc_ManCompare2 );
+    if ( fVerbose )
+        printf( "XOR3 cuts = %d.  MAJ cuts = %d.  Fadds = %d.\n", Vec_IntSize(vCutsXor)/4, Vec_IntSize(vCutsMaj)/4, Vec_IntSize(vFadds)/5 );
+    //Dtc_ManPrintFadds( vFadds );
+    Vec_IntFree( vCutsXor );
+    Vec_IntFree( vCutsMaj );
+    return vFadds;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Map each MAJ into the topmost MAJ of its chain.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+// maps MAJ nodes into FADD indexes
+Vec_Int_t * Gia_ManCreateMap( Gia_Man_t * p, Vec_Int_t * vFadds )
+{
+    Vec_Int_t * vMap = Vec_IntStartFull( Gia_ManObjNum(p) );  int i;
+    Dtc_ForEachFadd( vFadds, i )
         Vec_IntWriteEntry( vMap, Vec_IntEntry(vFadds, 5*i+4), i );
-    for ( i = 0; i < nObjs; i++ )
+    return vMap;
+}
+// find chain length (for each MAJ, how many FADDs are rooted in its first input)
+int Gia_ManFindChains_rec( Gia_Man_t * p, int iMaj, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Int_t * vLength )
+{
+    assert( Vec_IntEntry(vMap, iMaj) >= 0 ); // MAJ
+    if ( Vec_IntEntry(vLength, iMaj) >= 0 )
+        return Vec_IntEntry(vLength, iMaj);
+    assert( Gia_ObjIsAnd(Gia_ManObj(p, iMaj)) );
     {
-        int fFound = 0;
-        if ( (iFadd = Vec_IntEntry( vMap, Vec_IntEntry(vFadds, 5*i+0) )) >= 0 )
-            printf( "%d -> %d\n", iFadd, i ), fFound++;
-        if ( (iFadd = Vec_IntEntry( vMap, Vec_IntEntry(vFadds, 5*i+1) )) >= 0 )
-            printf( "%d -> %d\n", iFadd, i ), fFound++;
-        if ( (iFadd = Vec_IntEntry( vMap, Vec_IntEntry(vFadds, 5*i+2) )) >= 0 )
-            printf( "%d -> %d\n", iFadd, i ), fFound++;
-        if ( !fFound )
+        int iFadd = Vec_IntEntry( vMap, iMaj );
+        int iXor0 = Vec_IntEntry( vFadds, 5*iFadd+0 );
+        int iXor1 = Vec_IntEntry( vFadds, 5*iFadd+1 );
+        int iXor2 = Vec_IntEntry( vFadds, 5*iFadd+2 );
+        int iLen0 = Vec_IntEntry( vMap, iXor0 ) == -1 ? 0 : Gia_ManFindChains_rec( p, iXor0, vFadds, vMap, vLength );
+        int iLen1 = Vec_IntEntry( vMap, iXor1 ) == -1 ? 0 : Gia_ManFindChains_rec( p, iXor1, vFadds, vMap, vLength );
+        int iLen2 = Vec_IntEntry( vMap, iXor2 ) == -1 ? 0 : Gia_ManFindChains_rec( p, iXor2, vFadds, vMap, vLength );
+        int iLen = Abc_MaxInt( iLen0, Abc_MaxInt(iLen1, iLen2) );
+        if ( iLen0 < iLen )
+        {
+            if ( iLen == iLen1 )
+            {
+                ABC_SWAP( int, Vec_IntArray(vFadds)[5*iFadd+0], Vec_IntArray(vFadds)[5*iFadd+1] );
+            }
+            else if ( iLen == iLen2 )
+            {
+                ABC_SWAP( int, Vec_IntArray(vFadds)[5*iFadd+0], Vec_IntArray(vFadds)[5*iFadd+2] );
+            }
+        }
+        Vec_IntWriteEntry( vLength, iMaj, iLen + 1 );
+        return iLen + 1;
+    }
+}
+// for each FADD find the longest chain and reorder its inputs
+void Gia_ManFindChains( Gia_Man_t * p, Vec_Int_t * vFadds, Vec_Int_t * vMap )
+{
+    int i;
+    // for each FADD find the longest chain rooted in it
+    Vec_Int_t * vLength = Vec_IntStartFull( Gia_ManObjNum(p) );
+    Dtc_ForEachFadd( vFadds, i )
+        Gia_ManFindChains_rec( p, Vec_IntEntry(vFadds, 5*i+4), vFadds, vMap, vLength );
+    Vec_IntFree( vLength );
+}
+// collect one carry-chain
+void Gia_ManCollectOneChain( Gia_Man_t * p, Vec_Int_t * vFadds, int iFaddTop, Vec_Int_t * vMap, Vec_Int_t * vChain )
+{
+    int iFadd;
+    Vec_IntClear( vChain );
+    for ( iFadd = iFaddTop; iFadd >= 0 && 
+          !Gia_ObjIsTravIdCurrentId(p, Vec_IntEntry(vFadds, 5*iFadd+3)) && 
+          !Gia_ObjIsTravIdCurrentId(p, Vec_IntEntry(vFadds, 5*iFadd+4)); 
+          iFadd = Vec_IntEntry(vMap, Vec_IntEntry(vFadds, 5*iFadd+0)) )
+          {
+                Vec_IntPush( vChain, iFadd );
+          }
+    Vec_IntReverseOrder( vChain );
+}
+void Gia_ManMarkWithTravId_rec( Gia_Man_t * p, int Id )
+{
+    Gia_Obj_t * pObj;
+    if ( Gia_ObjIsTravIdCurrentId(p, Id) )
+        return;
+    Gia_ObjSetTravIdCurrentId(p, Id);
+    pObj = Gia_ManObj( p, Id );
+    if ( Gia_ObjIsAnd(pObj) )
+        Gia_ManMarkWithTravId_rec( p, Gia_ObjFaninId0(pObj, Id) );
+    if ( Gia_ObjIsAnd(pObj) )
+        Gia_ManMarkWithTravId_rec( p, Gia_ObjFaninId1(pObj, Id) );
+}
+// returns mapping of each MAJ into the topmost elements of its chain
+Vec_Wec_t * Gia_ManCollectTopmost( Gia_Man_t * p, Vec_Int_t * vFadds, Vec_Int_t * vMap, int nFaddMin )
+{
+    int i, j, iFadd;
+    Vec_Int_t * vChain  = Vec_IntAlloc( 100 );
+    Vec_Wec_t * vChains = Vec_WecAlloc( Vec_IntSize(vFadds)/5 );
+    // erase elements appearing as FADD inputs
+    Vec_Bit_t * vMarksTop = Vec_BitStart( Vec_IntSize(vFadds)/5 );
+    Dtc_ForEachFadd( vFadds, i )
+        if ( (iFadd = Vec_IntEntry(vMap, Vec_IntEntry(vFadds, 5*i+0))) >= 0 )
+            Vec_BitWriteEntry( vMarksTop, iFadd, 1 );
+    // compress the remaining ones
+    Gia_ManIncrementTravId( p );
+    Dtc_ForEachFadd( vFadds, i )
+    {
+        if ( Vec_BitEntry(vMarksTop, i) )
+            continue;
+        Gia_ManCollectOneChain( p, vFadds, i, vMap, vChain );
+        if ( Vec_IntSize(vChain) < nFaddMin )
+            continue;
+        Vec_IntAppend( Vec_WecPushLevel(vChains), vChain );
+        Vec_IntForEachEntry( vChain, iFadd, j )
+        {
+            assert( !Gia_ObjIsTravIdCurrentId(p, Vec_IntEntry(vFadds, 5*iFadd+3)) );
+            assert( !Gia_ObjIsTravIdCurrentId(p, Vec_IntEntry(vFadds, 5*iFadd+4)) );
+            Gia_ManMarkWithTravId_rec( p, Vec_IntEntry(vFadds, 5*iFadd+3) );
+            Gia_ManMarkWithTravId_rec( p, Vec_IntEntry(vFadds, 5*iFadd+4) );
+        }
+    }
+    // cleanup
+    Vec_BitFree( vMarksTop );
+    Vec_IntFree( vChain );
+    return vChains;
+}
+// prints chains beginning in majority nodes contained in vTops
+void Gia_ManPrintChains( Gia_Man_t * p, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Wec_t * vChains )
+{
+    Vec_Int_t * vChain;
+    int i, k, iFadd, Count = 0;
+    Vec_WecForEachLevel( vChains, vChain, i )
+    {
+        Count += Vec_IntSize(vChain);
+        if ( i < 10 )
+        {
+            printf( "Chain %4d : %4d    ", i, Vec_IntSize(vChain) );
+            Vec_IntForEachEntry( vChain, iFadd, k )
+            {
+                printf( "%d(%d) ", iFadd, Vec_IntEntry(vFadds, 5*iFadd+4) );
+                if ( k != Vec_IntSize(vChain) - 1 )
+                    printf( "-> " );
+                if ( k > 6 )
+                {
+                    printf( "..." );
+                    break;
+                }
+            }
             printf( "\n" );
-        if ( fFound > 1 )
-            Count++;
+        }
+        else if ( i == 10 )
+            printf( "...\n" );
+
     }
-//    printf( "%d \n", Count );
-    Vec_IntFree( vMap );
+    printf( "Total chains = %d. Total full-adders = %d.\n", Vec_WecSize(vChains), Count );
+}
+// map SUM bits and topmost MAJ into topmost FADD number
+Vec_Int_t * Gia_ManFindMapping( Gia_Man_t * p, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Wec_t * vChains )
+{
+    Vec_Int_t * vChain;
+    int i, k, iFadd;
+    Vec_Int_t * vMap2Chain = Vec_IntStartFull( Gia_ManObjNum(p) );
+    Vec_WecForEachLevel( vChains, vChain, i )
+    {
+        Vec_IntForEachEntry( vChain, iFadd, k )
+        {
+            //printf( "Chain %d: setting SUM %d (obj %d)\n", i, k, Vec_IntEntry(vFadds, 5*iFadd+3) );
+            assert( Vec_IntEntry(vMap2Chain, Vec_IntEntry(vFadds, 5*iFadd+3)) == -1 );
+            Vec_IntWriteEntry( vMap2Chain, Vec_IntEntry(vFadds, 5*iFadd+3), i );
+        }
+        //printf( "Chain %d: setting CARRY (obj %d)\n", i, Vec_IntEntry(vFadds, 5*iFadd+4) );
+        assert( Vec_IntEntry(vMap2Chain, Vec_IntEntry(vFadds, 5*iFadd+4)) == -1 );
+        Vec_IntWriteEntry( vMap2Chain, Vec_IntEntry(vFadds, 5*iFadd+4), i );
+    }
+    return vMap2Chain;
 }
 
 /**Function*************************************************************
 
-  Synopsis    []
+  Synopsis    [Derive GIA with boxes containing adder-chains.]
 
   Description []
                
@@ -276,19 +495,228 @@ void Dtc_ManSortChains( Gia_Man_t * p, Vec_Int_t * vFadds )
   SeeAlso     []
 
 ***********************************************************************/
-void Gia_ManDetectCarryChains( Gia_Man_t * p )
+Vec_Int_t * Gia_ManCollectTruthTables( Gia_Man_t * p, Vec_Int_t * vFadds )
 {
-    Vec_Int_t * vCutsXor, * vCutsMaj, * vFadds;
-    Dtc_ManComputeCuts( p, &vCutsXor, &vCutsMaj );
-    qsort( Vec_IntArray(vCutsXor), Vec_IntSize(vCutsXor)/4, 16, (int (*)(const void *, const void *))Dtc_ManCompare );
-    qsort( Vec_IntArray(vCutsMaj), Vec_IntSize(vCutsMaj)/4, 16, (int (*)(const void *, const void *))Dtc_ManCompare );
-    vFadds = Dtc_ManFindCommonCuts( p, vCutsXor, vCutsMaj );
-    printf( "XOR3 cuts = %d.  MAJ cuts = %d.  Fadds = %d.\n", Vec_IntSize(vCutsXor)/4, Vec_IntSize(vCutsMaj)/4, Vec_IntSize(vFadds)/5 );
-//    Dtc_ManPrintFadds( vFadds );
-    Dtc_ManSortChains( p, vFadds );
-    Vec_IntFree( vCutsXor );
-    Vec_IntFree( vCutsMaj );
+    int i, k, Type, Truth, pCut[4] = {3};
+    Vec_Int_t * vTruths = Vec_IntAlloc( 2*Vec_IntSize(vFadds)/5 );
+    Gia_ManCleanValue( p );
+    Dtc_ForEachFadd( vFadds, i )
+    {
+        for ( k = 0; k < 3; k++ )
+            pCut[k+1] = Vec_IntEntry( vFadds, 5*i+k );
+        Type = Dtc_ObjComputeTruth( p, Vec_IntEntry(vFadds, 5*i+3), pCut, &Truth );
+        assert( Type == 1 );
+        Vec_IntPush( vTruths, Truth );
+        Type = Dtc_ObjComputeTruth( p, Vec_IntEntry(vFadds, 5*i+4), pCut, &Truth );
+        assert( Type == 2 );
+        Vec_IntPush( vTruths, Truth );
+    }
+    return vTruths;
+}
+float * Gia_ManGenerateDelayTableFloat( int nIns, int nOuts )
+{
+    int i, Total = nIns * nOuts;
+    float * pDelayTable = ABC_ALLOC( float, Total + 3 );
+    pDelayTable[0] = 0;
+    pDelayTable[1] = nIns;
+    pDelayTable[2] = nOuts;
+    for ( i = 0; i < Total; i++ )
+        pDelayTable[i+3] = 1;
+    pDelayTable[i+3 - nIns] = -ABC_INFINITY;
+    return pDelayTable;
+}
+Tim_Man_t * Gia_ManGenerateTim( int nPis, int nPos, int nBoxes, int nIns, int nOuts )
+{
+    Tim_Man_t * pMan;
+    int i, curPi, curPo;
+    Vec_Ptr_t * vDelayTables = Vec_PtrAlloc( 1 );
+    Vec_PtrPush( vDelayTables, Gia_ManGenerateDelayTableFloat(nIns, nOuts) );
+    pMan = Tim_ManStart( nPis + nOuts * nBoxes, nPos + nIns * nBoxes );
+    Tim_ManSetDelayTables( pMan, vDelayTables );
+    curPi = nPis;
+    curPo = 0;
+    for ( i = 0; i < nBoxes; i++ )
+    {
+        Tim_ManCreateBox( pMan, curPo, nIns, curPi, nOuts, 0 );
+        curPi += nOuts;
+        curPo += nIns;
+    }
+    curPo += nPos;
+    assert( curPi == Tim_ManCiNum(pMan) );
+    assert( curPo == Tim_ManCoNum(pMan) );
+    //Tim_ManPrint( pMan );
+    return pMan;
+}
+Gia_Man_t * Gia_ManGenerateExtraAig( int nBoxes, int nIns, int nOuts )
+{
+    Gia_Man_t * pNew = Gia_ManStart( nBoxes * 20 );
+    int i, k, pInLits[16], pOutLits[16];
+    assert( nIns < 16 && nOuts < 16 );
+    for ( i = 0; i < nIns; i++ )
+        pInLits[i] = Gia_ManAppendCi( pNew );
+    pOutLits[0] = Gia_ManAppendXor( pNew, Gia_ManAppendXor(pNew, pInLits[0], pInLits[1]), pInLits[2] );
+    pOutLits[1] = Gia_ManAppendMaj( pNew, pInLits[0], pInLits[1], pInLits[2] );
+    for ( i = 0; i < nBoxes; i++ )
+        for ( k = 0; k < nOuts; k++ )
+            Gia_ManAppendCo( pNew, pOutLits[k] );
+    return pNew;
+}
+void Gia_ManDupFadd( Gia_Man_t * pNew, Gia_Man_t * p, Vec_Int_t * vChain, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Wec_t * vChains, Vec_Int_t * vMap2Chain, Vec_Int_t * vTruths )
+{
+    extern void Gia_ManDupWithFaddBoxes_rec( Gia_Man_t * pNew, Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Wec_t * vChains, Vec_Int_t * vMap2Chain, Vec_Int_t * vTruths );
+    int i, k, iFadd, iCiLit, pLits[3];
+    Gia_Obj_t * pObj;
+    // construct FADD inputs
+    Vec_IntForEachEntry( vChain, iFadd, i )
+        for ( k = 0; k < 3; k++ )
+        {
+            if ( i && !k ) continue;
+            pObj = Gia_ManObj( p, Vec_IntEntry(vFadds, 5*iFadd+k) );
+            Gia_ManDupWithFaddBoxes_rec( pNew, p, pObj, vFadds, vMap, vChains, vMap2Chain, vTruths );
+        }
+    // construct boxes
+    iCiLit = 0;
+    Vec_IntForEachEntry( vChain, iFadd, i )
+    {
+        int iXorTruth = Vec_IntEntry( vTruths, 2*iFadd+0 );
+        int iMajTruth = Vec_IntEntry( vTruths, 2*iFadd+1 );
+        for ( k = 0; k < 3; k++ )
+        {
+            pObj = Gia_ManObj( p, Vec_IntEntry(vFadds, 5*iFadd+k) );
+            pLits[k] = (!k && iCiLit) ? iCiLit : pObj->Value;
+            assert( pLits[k] >= 0 );
+        }
+        // normalize truth table
+        //    if ( Truth == 0xE8 || Truth == 0xD4 || Truth == 0xB2 || Truth == 0x71 ||
+        //         Truth == 0x17 || Truth == 0x2B || Truth == 0x4D || Truth == 0x8E )
+        if ( iMajTruth == 0x4D )
+            pLits[0] = Abc_LitNot(pLits[0]), iMajTruth = 0x8E, iXorTruth = 0xFF & ~iXorTruth;
+        else if ( iMajTruth == 0xD4 )
+            pLits[0] = Abc_LitNot(pLits[0]), iMajTruth = 0xE8, iXorTruth = 0xFF & ~iXorTruth;
+        else if ( iMajTruth == 0x2B )
+            pLits[1] = Abc_LitNot(pLits[1]), iMajTruth = 0x8E, iXorTruth = 0xFF & ~iXorTruth;
+        else if ( iMajTruth == 0xB2 )
+            pLits[1] = Abc_LitNot(pLits[1]), iMajTruth = 0xE8, iXorTruth = 0xFF & ~iXorTruth;
+        if ( iMajTruth == 0x8E )
+            pLits[2] = Abc_LitNot(pLits[2]), iMajTruth = 0xE8, iXorTruth = 0xFF & ~iXorTruth;
+        else if ( iMajTruth == 0x71 )
+            pLits[2] = Abc_LitNot(pLits[2]), iMajTruth = 0x17, iXorTruth = 0xFF & ~iXorTruth;
+        else assert( iMajTruth == 0xE8 || iMajTruth == 0x17 );
+        // normalize carry-in
+        if ( Abc_LitIsCompl(pLits[0]) )
+        {
+            for ( k = 0; k < 3; k++ )
+                pLits[k] = Abc_LitNot(pLits[k]);
+            iXorTruth = 0xFF & ~iXorTruth;
+            iMajTruth = 0xFF & ~iMajTruth;
+        }
+        // add COs
+        assert( !Abc_LitIsCompl(pLits[0]) );
+        for ( k = 0; k < 3; k++ )
+            Gia_ManAppendCo( pNew, pLits[k] );
+        // create CI
+        assert( iXorTruth == 0x96 || iXorTruth == 0x69 );
+        pObj = Gia_ManObj( p, Vec_IntEntry(vFadds, 5*iFadd+3) );
+        pObj->Value = Abc_LitNotCond( Gia_ManAppendCi(pNew), (int)(iXorTruth == 0x69) );
+        // create CI
+        assert( iMajTruth == 0xE8 || iMajTruth == 0x17 );
+        iCiLit = Abc_LitNotCond( Gia_ManAppendCi(pNew), (int)(iMajTruth == 0x17) );
+    }   
+    // assign carry out
+    assert( iFadd == Vec_IntEntryLast(vChain) );
+    pObj = Gia_ManObj( p, Vec_IntEntry(vFadds, 5*iFadd+4) );
+    pObj->Value = iCiLit;
+}
+void Gia_ManDupWithFaddBoxes_rec( Gia_Man_t * pNew, Gia_Man_t * p, Gia_Obj_t * pObj, Vec_Int_t * vFadds, Vec_Int_t * vMap, Vec_Wec_t * vChains, Vec_Int_t * vMap2Chain, Vec_Int_t * vTruths )
+{
+    int iChain;
+    if ( ~pObj->Value )
+        return;
+    assert( Gia_ObjIsAnd(pObj) );
+    iChain = Vec_IntEntry( vMap2Chain, Gia_ObjId(p, pObj) );
+/*
+    assert( iChain == -1 );
+    if ( iChain >= 0 )
+    {
+        Gia_ManDupFadd( pNew, p, Vec_WecEntry(vChains, iChain), vFadds, vMap, vChains, vMap2Chain, vTruths );
+        assert( ~pObj->Value );
+        return;
+    }
+*/
+    Gia_ManDupWithFaddBoxes_rec( pNew, p, Gia_ObjFanin0(pObj), vFadds, vMap, vChains, vMap2Chain, vTruths );
+    Gia_ManDupWithFaddBoxes_rec( pNew, p, Gia_ObjFanin1(pObj), vFadds, vMap, vChains, vMap2Chain, vTruths );
+    pObj->Value = Gia_ManAppendAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+}
+Gia_Man_t * Gia_ManDupWithFaddBoxes( Gia_Man_t * p, int nFaddMin, int fVerbose )
+{
+    Gia_Man_t * pNew, * pTemp;
+    Vec_Int_t * vFadds, * vMap, * vMap2Chain, * vTruths, * vChain;
+    Vec_Wec_t * vChains;
+    Gia_Obj_t * pObj;  
+    int i, nBoxes;
+
+    // detect FADDs
+    vFadds = Gia_ManDetectFullAdders( p, fVerbose );
+    assert( Vec_IntSize(vFadds) % 5 == 0 );
+    // map MAJ into its FADD
+    vMap = Gia_ManCreateMap( p, vFadds );
+    // for each FADD, find the longest chain and reorder its inputs
+    Gia_ManFindChains( p, vFadds, vMap );
+    // returns the set of topmost MAJ nodes
+    vChains = Gia_ManCollectTopmost( p, vFadds, vMap, nFaddMin );
+    if ( fVerbose )
+        Gia_ManPrintChains( p, vFadds, vMap, vChains );
+    if ( Vec_WecSize(vChains) == 0 )
+    {
+        Vec_IntFree( vFadds );
+        Vec_IntFree( vMap );
+        Vec_WecFree( vChains );
+        return Gia_ManDup( p );
+    }
+    // returns mapping of each MAJ into the topmost elements of its chain
+    vMap2Chain = Gia_ManFindMapping( p, vFadds, vMap, vChains );
+    // compute truth tables for FADDs
+    vTruths = Gia_ManCollectTruthTables( p, vFadds );
+
+    // duplicate
+    Gia_ManFillValue( p );
+    pNew = Gia_ManStart( Gia_ManObjNum(p) );
+    pNew->pName = Abc_UtilStrsav( p->pName );
+    pNew->pSpec = Abc_UtilStrsav( p->pSpec );
+    Gia_ManConst0(p)->Value = 0;
+    Gia_ManForEachCi( p, pObj, i )
+        pObj->Value = Gia_ManAppendCi( pNew );
+    Vec_WecForEachLevel( vChains, vChain, i )
+        Gia_ManDupFadd( pNew, p, vChain, vFadds, vMap, vChains, vMap2Chain, vTruths );
+    Gia_ManForEachCo( p, pObj, i )
+        Gia_ManDupWithFaddBoxes_rec( pNew, p, Gia_ObjFanin0(pObj), vFadds, vMap, vChains, vMap2Chain, vTruths );
+    Gia_ManForEachCo( p, pObj, i )
+        Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
+    Gia_ManSetRegNum( pNew, Gia_ManRegNum(p) );
+    assert( !Gia_ManHasDangling(pNew) );
+
+    // cleanup
     Vec_IntFree( vFadds );
+    Vec_IntFree( vMap );
+    Vec_WecFree( vChains );
+    Vec_IntFree( vMap2Chain );
+    Vec_IntFree( vTruths );
+
+    // normalize
+    pNew = Gia_ManDupNormalize( pTemp = pNew );
+    Gia_ManStop( pTemp );
+    
+    // other information
+    nBoxes = (Gia_ManCiNum(pNew) - Gia_ManCiNum(p)) / 2;
+    assert( nBoxes == (Gia_ManCoNum(pNew) - Gia_ManCoNum(p)) / 3 );
+    pNew->pManTime  = Gia_ManGenerateTim( Gia_ManCiNum(p), Gia_ManCoNum(p), nBoxes, 3, 2 );
+    pNew->pAigExtra = Gia_ManGenerateExtraAig( nBoxes, 3, 2 );
+
+    //pNew = Gia_ManDupCollapse( pTemp = pNew, pNew->pAigExtra, NULL );
+    //Gia_ManStop( pTemp );
+
+    //Gia_ManIllustrateBoxes( pNew );
+    return pNew;
 }
 
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/aig/gia/giaTim.c b/src/aig/gia/giaTim.c
index 290cae7d..12c379c0 100644
--- a/src/aig/gia/giaTim.c
+++ b/src/aig/gia/giaTim.c
@@ -117,7 +117,7 @@ Vec_Int_t * Gia_ManOrderWithBoxes( Gia_Man_t * p )
     // include primary inputs
     for ( i = 0; i < Tim_ManPiNum(pManTime); i++ )
     {
-        pObj = Gia_ManPi( p, i );
+        pObj = Gia_ManCi( p, i );
         Vec_IntPush( vNodes, Gia_ObjId(p, pObj) );
         Gia_ObjSetTravIdCurrent( p, pObj );
         assert( Gia_ObjId(p, pObj) == i+1 );
@@ -130,7 +130,7 @@ Vec_Int_t * Gia_ManOrderWithBoxes( Gia_Man_t * p )
         // add internal nodes
         for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
         {
-            pObj = Gia_ManPo( p, curCo + k );
+            pObj = Gia_ManCo( p, curCo + k );
             if ( Gia_ManOrderWithBoxes_rec( p, Gia_ObjFanin0(pObj), vNodes ) )
             {
                 int iCiNum  = p->iData2;
@@ -151,14 +151,14 @@ Vec_Int_t * Gia_ManOrderWithBoxes( Gia_Man_t * p )
         // add POs corresponding to box inputs
         for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
         {
-            pObj = Gia_ManPo( p, curCo + k );
+            pObj = Gia_ManCo( p, curCo + k );
             Vec_IntPush( vNodes, Gia_ObjId(p, pObj) );
         }
         curCo += Tim_ManBoxInputNum(pManTime, i);
         // add PIs corresponding to box outputs
         for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
         {
-            pObj = Gia_ManPi( p, curCi + k );
+            pObj = Gia_ManCi( p, curCi + k );
             Vec_IntPush( vNodes, Gia_ObjId(p, pObj) );
             Gia_ObjSetTravIdCurrent( p, pObj );
         }
@@ -167,19 +167,19 @@ Vec_Int_t * Gia_ManOrderWithBoxes( Gia_Man_t * p )
     // add remaining nodes
     for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
     {
-        pObj = Gia_ManPo( p, i );
+        pObj = Gia_ManCo( p, i );
         Gia_ManOrderWithBoxes_rec( p, Gia_ObjFanin0(pObj), vNodes );
     }
     // add POs
     for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
     {
-        pObj = Gia_ManPo( p, i );
+        pObj = Gia_ManCo( p, i );
         Vec_IntPush( vNodes, Gia_ObjId(p, pObj) );
     }
     curCo += Tim_ManPoNum(pManTime);
     // verify counts
-    assert( curCi == Gia_ManPiNum(p) );
-    assert( curCo == Gia_ManPoNum(p) );
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
     assert( Vec_IntSize(vNodes) == Gia_ManObjNum(p) );
     return vNodes;
 }
@@ -292,8 +292,8 @@ Gia_Man_t * Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * v
     Gia_Man_t * pNew, * pTemp;
     Gia_Obj_t * pObj, * pObjBox;
     int i, k, curCi, curCo;
-    assert( Gia_ManRegNum(p) == 0 );
-    assert( Gia_ManPiNum(p) == Tim_ManPiNum(pManTime) + Gia_ManPoNum(pBoxes) );
+    //assert( Gia_ManRegNum(p) == 0 );
+    assert( Gia_ManCiNum(p) == Tim_ManPiNum(pManTime) + Gia_ManCoNum(pBoxes) );
     pNew = Gia_ManStart( Gia_ManObjNum(p) );
     pNew->pName = Abc_UtilStrsav( p->pName );
     pNew->pSpec = Abc_UtilStrsav( p->pSpec );
@@ -307,7 +307,7 @@ Gia_Man_t * Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * v
     Gia_ObjSetTravIdCurrent( p, Gia_ManConst0(p) );
     for ( i = 0; i < Tim_ManPiNum(pManTime); i++ )
     {
-        pObj = Gia_ManPi( p, i );
+        pObj = Gia_ManCi( p, i );
         pObj->Value = Gia_ManAppendCi(pNew);
         Gia_ObjSetTravIdCurrent( p, pObj );
     }
@@ -326,13 +326,13 @@ Gia_Man_t * Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * v
             int fSkip = (vBoxPres != NULL && !Vec_IntEntry(vBoxPres, i));
             for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
             {
-                pObj = Gia_ManPo( p, curCo + k );
+                pObj = Gia_ManCo( p, curCo + k );
                 Gia_ManDupCollapse_rec( p, Gia_ObjFanin0(pObj), pNew );
                 pObj->Value = fSkip ? -1 : Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
             }
             for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
             {
-                pObj = Gia_ManPi( p, curCi + k );
+                pObj = Gia_ManCi( p, curCi + k );
                 pObj->Value = fSkip ? 0 : Gia_ManAppendCi(pNew);
                 Gia_ObjSetTravIdCurrent( p, pObj );
             }
@@ -342,20 +342,20 @@ Gia_Man_t * Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * v
             for ( k = 0; k < Tim_ManBoxInputNum(pManTime, i); k++ )
             {
                 // build logic
-                pObj = Gia_ManPo( p, curCo + k );
+                pObj = Gia_ManCo( p, curCo + k );
                 Gia_ManDupCollapse_rec( p, Gia_ObjFanin0(pObj), pNew );
                 // transfer to the PI
-                pObjBox = Gia_ManPi( pBoxes, k );
+                pObjBox = Gia_ManCi( pBoxes, k );
                 pObjBox->Value = Gia_ObjFanin0Copy(pObj);
                 Gia_ObjSetTravIdCurrent( pBoxes, pObjBox );
             }
             for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
             {
                 // build logic
-                pObjBox = Gia_ManPo( pBoxes, curCi - Tim_ManPiNum(pManTime) + k );
+                pObjBox = Gia_ManCo( pBoxes, curCi - Tim_ManPiNum(pManTime) + k );
                 Gia_ManDupCollapse_rec( pBoxes, Gia_ObjFanin0(pObjBox), pNew );
                 // transfer to the PI
-                pObj = Gia_ManPi( p, curCi + k );
+                pObj = Gia_ManCi( p, curCi + k );
                 pObj->Value = Gia_ObjFanin0Copy(pObjBox);
                 Gia_ObjSetTravIdCurrent( p, pObj );
             }
@@ -366,21 +366,21 @@ Gia_Man_t * Gia_ManDupCollapse( Gia_Man_t * p, Gia_Man_t * pBoxes, Vec_Int_t * v
     // add remaining nodes
     for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
     {
-        pObj = Gia_ManPo( p, i );
+        pObj = Gia_ManCo( p, i );
         Gia_ManDupCollapse_rec( p, Gia_ObjFanin0(pObj), pNew );
         pObj->Value = Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
     }
     curCo += Tim_ManPoNum(pManTime);
     // verify counts
-    assert( curCi == Gia_ManPiNum(p) );
-    assert( curCo == Gia_ManPoNum(p) );
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
     Gia_ManSetRegNum( pNew, Gia_ManRegNum(p) );
     Gia_ManHashStop( pNew );
     pNew = Gia_ManCleanup( pTemp = pNew );
     Gia_ManCleanupRemap( p, pTemp );
     Gia_ManStop( pTemp );
-    assert( Tim_ManPoNum(pManTime) == Gia_ManPoNum(pNew) );
-    assert( Tim_ManPiNum(pManTime) == Gia_ManPiNum(pNew) );
+    assert( Tim_ManPoNum(pManTime) == Gia_ManCoNum(pNew) );
+    assert( Tim_ManPiNum(pManTime) == Gia_ManCiNum(pNew) );
     return pNew;
 }
 
@@ -426,7 +426,7 @@ int Gia_ManLevelWithBoxes( Gia_Man_t * p )
     Gia_ObjSetTravIdCurrent( p, Gia_ManConst0(p) );
     for ( i = 0; i < Tim_ManPiNum(pManTime); i++ )
     {
-        pObj = Gia_ManPi( p, i );
+        pObj = Gia_ManCi( p, i );
         Gia_ObjSetLevel( p, pObj, Tim_ManGetCiArrival(pManTime, i) / nAnd2Delay );
         Gia_ObjSetTravIdCurrent( p, pObj );
     }
@@ -441,7 +441,7 @@ int Gia_ManLevelWithBoxes( Gia_Man_t * p )
         // compute level for TFI of box inputs
         for ( k = 0; k < nBoxInputs; k++ )
         {
-            pObj = Gia_ManPo( p, curCo + k );
+            pObj = Gia_ManCo( p, curCo + k );
             if ( Gia_ManLevelWithBoxes_rec( p, Gia_ObjFanin0(pObj) ) )
             {
                 printf( "Boxes are not in a topological order. Switching to level computation without boxes.\n" );
@@ -453,12 +453,12 @@ int Gia_ManLevelWithBoxes( Gia_Man_t * p )
         // compute level for box outputs
         for ( k = 0; k < nBoxOutputs; k++ )
         {
-            pObj = Gia_ManPi( p, curCi + k );
+            pObj = Gia_ManCi( p, curCi + k );
             Gia_ObjSetTravIdCurrent( p, pObj );
             // evaluate delay of this output
             LevelMax = 0;
             assert( nBoxInputs == (int)pDelayTable[1] );
-            for ( j = 0; j < nBoxInputs && (pObjIn = Gia_ManPo(p, curCo + j)); j++ )
+            for ( j = 0; j < nBoxInputs && (pObjIn = Gia_ManCo(p, curCo + j)); j++ )
                 if ( (int)pDelayTable[3+k*nBoxInputs+j] != -ABC_INFINITY )
                     LevelMax = Abc_MaxInt( LevelMax, Gia_ObjLevel(p, pObjIn) + ((int)pDelayTable[3+k*nBoxInputs+j] / nAnd2Delay) );
             // set box output level
@@ -471,15 +471,15 @@ int Gia_ManLevelWithBoxes( Gia_Man_t * p )
     p->nLevels = 0;
     for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
     {
-        pObj = Gia_ManPo( p, i );
+        pObj = Gia_ManCo( p, i );
         Gia_ManLevelWithBoxes_rec( p, Gia_ObjFanin0(pObj) );
         Gia_ObjSetCoLevel( p, pObj );
         p->nLevels = Abc_MaxInt( p->nLevels, Gia_ObjLevel(p, pObj) );
     }
     curCo += Tim_ManPoNum(pManTime);
     // verify counts
-    assert( curCi == Gia_ManPiNum(p) );
-    assert( curCo == Gia_ManPoNum(p) );
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
 //    printf( "Max level is %d.\n", p->nLevels );
     return p->nLevels;
 }
@@ -528,7 +528,7 @@ int Gia_ManLutLevelWithBoxes( Gia_Man_t * p )
     Gia_ObjSetTravIdCurrent( p, Gia_ManConst0(p) );
     for ( i = 0; i < Tim_ManPiNum(pManTime); i++ )
     {
-        pObj = Gia_ManPi( p, i );
+        pObj = Gia_ManCi( p, i );
 //        Gia_ObjSetLevel( p, pObj, Tim_ManGetCiArrival(pManTime, i) / nAnd2Delay );
         Gia_ObjSetLevel( p, pObj, 0 );
         Gia_ObjSetTravIdCurrent( p, pObj );
@@ -544,7 +544,7 @@ int Gia_ManLutLevelWithBoxes( Gia_Man_t * p )
         // compute level for TFI of box inputs
         for ( k = 0; k < nBoxInputs; k++ )
         {
-            pObj = Gia_ManPo( p, curCo + k );
+            pObj = Gia_ManCo( p, curCo + k );
             if ( Gia_ManLutLevelWithBoxes_rec( p, Gia_ObjFanin0(pObj) ) )
             {
                 printf( "Boxes are not in a topological order. Switching to level computation without boxes.\n" );
@@ -556,12 +556,12 @@ int Gia_ManLutLevelWithBoxes( Gia_Man_t * p )
         // compute level for box outputs
         for ( k = 0; k < nBoxOutputs; k++ )
         {
-            pObj = Gia_ManPi( p, curCi + k );
+            pObj = Gia_ManCi( p, curCi + k );
             Gia_ObjSetTravIdCurrent( p, pObj );
             // evaluate delay of this output
             LevelMax = 0;
             assert( nBoxInputs == (int)pDelayTable[1] );
-            for ( j = 0; j < nBoxInputs && (pObjIn = Gia_ManPo(p, curCo + j)); j++ )
+            for ( j = 0; j < nBoxInputs && (pObjIn = Gia_ManCo(p, curCo + j)); j++ )
                 if ( (int)pDelayTable[3+k*nBoxInputs+j] != -ABC_INFINITY )
 //                    LevelMax = Abc_MaxInt( LevelMax, Gia_ObjLevel(p, pObjIn) + ((int)pDelayTable[3+k*nBoxInputs+j] / nAnd2Delay) );
                     LevelMax = Abc_MaxInt( LevelMax, Gia_ObjLevel(p, pObjIn) + 1 );
@@ -575,15 +575,15 @@ int Gia_ManLutLevelWithBoxes( Gia_Man_t * p )
     p->nLevels = 0;
     for ( i = Tim_ManCoNum(pManTime) - Tim_ManPoNum(pManTime); i < Tim_ManCoNum(pManTime); i++ )
     {
-        pObj = Gia_ManPo( p, i );
+        pObj = Gia_ManCo( p, i );
         Gia_ManLutLevelWithBoxes_rec( p, Gia_ObjFanin0(pObj) );
         Gia_ObjSetCoLevel( p, pObj );
         p->nLevels = Abc_MaxInt( p->nLevels, Gia_ObjLevel(p, pObj) );
     }
     curCo += Tim_ManPoNum(pManTime);
     // verify counts
-    assert( curCi == Gia_ManPiNum(p) );
-    assert( curCo == Gia_ManPoNum(p) );
+    assert( curCi == Gia_ManCiNum(p) );
+    assert( curCo == Gia_ManCoNum(p) );
 //    printf( "Max level is %d.\n", p->nLevels );
     return p->nLevels;
 }
@@ -714,14 +714,14 @@ Gia_Man_t * Gia_ManUpdateExtraAig( void * pTime, Gia_Man_t * p, Vec_Int_t * vBox
     Vec_Int_t * vOutPres = Vec_IntAlloc( 100 );
     int i, k, curPo = 0;
     assert( Vec_IntSize(vBoxPres) == Tim_ManBoxNum(pManTime) );
-    assert( Gia_ManPoNum(p) == Tim_ManCiNum(pManTime) - Tim_ManPiNum(pManTime) );
+    assert( Gia_ManCoNum(p) == Tim_ManCiNum(pManTime) - Tim_ManPiNum(pManTime) );
     for ( i = 0; i < Tim_ManBoxNum(pManTime); i++ )
     {
         for ( k = 0; k < Tim_ManBoxOutputNum(pManTime, i); k++ )
             Vec_IntPush( vOutPres, Vec_IntEntry(vBoxPres, i) );
         curPo += Tim_ManBoxOutputNum(pManTime, i);
     }
-    assert( curPo == Gia_ManPoNum(p) );
+    assert( curPo == Gia_ManCoNum(p) );
 //    if ( Vec_IntSize(vOutPres) > 0 )
         pNew = Gia_ManDupOutputVec( p, vOutPres );
     Vec_IntFree( vOutPres );
diff --git a/src/aig/gia/module.make b/src/aig/gia/module.make
index 4e830971..0c456333 100644
--- a/src/aig/gia/module.make
+++ b/src/aig/gia/module.make
@@ -21,6 +21,7 @@ SRC +=    src/aig/gia/giaAig.c \
     src/aig/gia/giaEquiv.c \
     src/aig/gia/giaEra.c \
     src/aig/gia/giaEra2.c \
+    src/aig/gia/giaFadds.c \
     src/aig/gia/giaFalse.c \
     src/aig/gia/giaFanout.c \
     src/aig/gia/giaForce.c \
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index 7bd2b617..c0591571 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -439,6 +439,7 @@ static int Abc_CommandAbc9Maxi               ( Abc_Frame_t * pAbc, int argc, cha
 static int Abc_CommandAbc9Bmci               ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9PoXsim             ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Demiter            ( Abc_Frame_t * pAbc, int argc, char ** argv );
+static int Abc_CommandAbc9Fadds              ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9PoPart2            ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9CexCut             ( Abc_Frame_t * pAbc, int argc, char ** argv );
 //static int Abc_CommandAbc9CexMerge           ( Abc_Frame_t * pAbc, int argc, char ** argv );
@@ -1040,6 +1041,7 @@ void Abc_Init( Abc_Frame_t * pAbc )
     Cmd_CommandAdd( pAbc, "ABC9",         "&bmci",         Abc_CommandAbc9Bmci,         0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&poxsim",       Abc_CommandAbc9PoXsim,       0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&demiter",      Abc_CommandAbc9Demiter,      0 );
+    Cmd_CommandAdd( pAbc, "ABC9",         "&fadds",        Abc_CommandAbc9Fadds,        0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&popart2",      Abc_CommandAbc9PoPart2,      0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&cexcut",       Abc_CommandAbc9CexCut,       0 );
 //    Cmd_CommandAdd( pAbc, "ABC9",         "&cexmerge",     Abc_CommandAbc9CexMerge,     0 );
@@ -36557,6 +36559,64 @@ usage:
   SeeAlso     []
 
 ***********************************************************************/
+int Abc_CommandAbc9Fadds( Abc_Frame_t * pAbc, int argc, char ** argv )
+{
+    extern Gia_Man_t * Gia_ManDupWithFaddBoxes( Gia_Man_t * p, int nFaddMin, int fVerbose );
+    Gia_Man_t * pTemp;
+    int c, nFaddMin = 3, fVerbose = 0;
+    Extra_UtilGetoptReset();
+    while ( ( c = Extra_UtilGetopt( argc, argv, "Nvh" ) ) != EOF )
+    {
+        switch ( c )
+        {
+        case 'N':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-N\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nFaddMin = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nFaddMin < 0 )
+                goto usage;
+            break;
+        case 'v':
+            fVerbose ^= 1;
+            break;
+        case 'h':
+            goto usage;
+        default:
+            goto usage;
+        }
+    }
+    if ( pAbc->pGia == NULL )
+    {
+        Abc_Print( -1, "Abc_CommandAbc9Fadds(): There is no AIG.\n" );
+        return 0;
+    }
+    pTemp = Gia_ManDupWithFaddBoxes( pAbc->pGia, nFaddMin, fVerbose );
+    Abc_FrameUpdateGia( pAbc, pTemp );
+    return 0;
+usage:
+    Abc_Print( -2, "usage: &fadds [-N num] [-vh]\n" );
+    Abc_Print( -2, "\t         detects full-adder chains and puts them into white boxes\n" );
+    Abc_Print( -2, "\t-N num : the minimum length of full-adder chain to box [default = %d]\n", nFaddMin );
+    Abc_Print( -2, "\t-v     : toggles printing verbose information [default = %s]\n",  fVerbose? "yes": "no" );
+    Abc_Print( -2, "\t-h     : print the command usage\n");
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
 int Abc_CommandAbc9CexCut( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
     return -1;