Extending NDR to support adder/subtractor.

3 files changed, 72 insertions, 6 deletions

diff --git a/src/aig/miniaig/ndr.h b/src/aig/miniaig/ndr.h
index 71a9d5ac..b33d9c6d 100644
--- a/src/aig/miniaig/ndr.h
+++ b/src/aig/miniaig/ndr.h
@@ -1044,6 +1044,42 @@ static inline void Ndr_ModuleTestDec()
     Ndr_Delete( pDesign );
 }
 
+// This testing procedure creates and writes into a Verilog file 
+// the following design composed of one adder/subtractor
+
+// module addsub ( input mode, input cin, input [2:0] a, input [2:0] b, output [3:0] out );
+//     assign out = mode ? a+b+cin : a-b-cin ;
+// endmodule
+
+static inline void Ndr_ModuleTestAddSub()
+{
+    // map name IDs into char strings
+    //char * ppNames[12] = { NULL, "addsub", "mode", "cin", "a", "b", "out" };
+    // name IDs
+    int NameIdInMode =  2;
+    int NameIdInCin  =  3;
+    int NameIdInA    =  4;
+    int NameIdInB    =  5;
+    int NameIdOut    =  6;
+    int Fanins[8] = { 2, 3, 4, 5 };
+
+    // create a new module
+    void * pDesign = Ndr_Create( 1 );
+
+    int ModuleID = Ndr_AddModule( pDesign, 1 );
+
+    // add objects to the modele
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_CI,          0,   0, 0, 0,   0, NULL,       1, &NameIdInMode, NULL );
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_CI,          0,   0, 0, 0,   0, NULL,       1, &NameIdInCin,  NULL );
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_CI,          0,   2, 0, 0,   0, NULL,       1, &NameIdInA,    NULL );
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_CI,          0,   2, 0, 0,   0, NULL,       1, &NameIdInB,    NULL );
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_ARI_ADDSUB,  0,   3, 0, 0,   4, Fanins,     1, &NameIdOut,    NULL );
+    Ndr_AddObject( pDesign, ModuleID, ABC_OPER_CO,          0,   3, 0, 0,   1, &NameIdOut, 0, NULL,          NULL );
+
+    Ndr_Write( "addsub.ndr", pDesign );
+    Ndr_Delete( pDesign );
+}
+
 ABC_NAMESPACE_HEADER_END
 
 #endif
diff --git a/src/base/wlc/wlcBlast.c b/src/base/wlc/wlcBlast.c
index c16c89c6..2efed1f8 100644
--- a/src/base/wlc/wlcBlast.c
+++ b/src/base/wlc/wlcBlast.c
@@ -345,9 +345,9 @@ void Wlc_BlastAdder( Gia_Man_t * pNew, int * pAdd0, int * pAdd1, int nBits, int
     for ( b = 0; b < nBits; b++ )
         Wlc_BlastFullAdder( pNew, pAdd0[b], pAdd1[b], Carry, &Carry, &pAdd0[b] );
 }
-void Wlc_BlastSubtract( Gia_Man_t * pNew, int * pAdd0, int * pAdd1, int nBits ) // result is in pAdd0
+void Wlc_BlastSubtract( Gia_Man_t * pNew, int * pAdd0, int * pAdd1, int nBits, int Carry ) // result is in pAdd0
 {
-    int b, Carry = 1;
+    int b;
     for ( b = 0; b < nBits; b++ )
         Wlc_BlastFullAdder( pNew, pAdd0[b], Abc_LitNot(pAdd1[b]), Carry, &Carry, &pAdd0[b] );
 }
@@ -1138,8 +1138,8 @@ Gia_Man_t * Wlc_NtkBitBlast( Wlc_Ntk_t * p, Wlc_BstPar_t * pParIn )
     Wlc_Obj_t * pObj, * pObj2;
     Vec_Int_t * vBits = &p->vBits, * vTemp0, * vTemp1, * vTemp2, * vRes, * vAddOutputs = NULL, * vAddObjs = NULL;
     int nBits = Wlc_NtkPrepareBits( p );
-    int nRange, nRange0, nRange1, nRange2;
-    int i, k, b, iFanin, iLit, nAndPrev, * pFans0, * pFans1, * pFans2;
+    int nRange, nRange0, nRange1, nRange2, nRange3;
+    int i, k, b, iFanin, iLit, nAndPrev, * pFans0, * pFans1, * pFans2, * pFans3;
     int nFFins = 0, nFFouts = 0, curPi = 0, curPo = 0;
     int nBitCis = 0, nBitCos = 0, fAdded = 0;
     Wlc_BstPar_t Par, * pPar = &Par;
@@ -1209,9 +1209,11 @@ Gia_Man_t * Wlc_NtkBitBlast( Wlc_Ntk_t * p, Wlc_BstPar_t * pParIn )
         nRange0 = Wlc_ObjFaninNum(pObj) > 0 ? Wlc_ObjRange( Wlc_ObjFanin0(p, pObj) ) : -1;
         nRange1 = Wlc_ObjFaninNum(pObj) > 1 ? Wlc_ObjRange( Wlc_ObjFanin1(p, pObj) ) : -1;
         nRange2 = Wlc_ObjFaninNum(pObj) > 2 ? Wlc_ObjRange( Wlc_ObjFanin2(p, pObj) ) : -1;
+        nRange3 = Wlc_ObjFaninNum(pObj) > 3 ? Wlc_ObjRange( Wlc_ObjFanin(p, pObj, 3) ) : -1;
         pFans0  = Wlc_ObjFaninNum(pObj) > 0 ? Vec_IntEntryP( vBits, Wlc_ObjCopy(p, Wlc_ObjFaninId0(pObj)) ) : NULL;
         pFans1  = Wlc_ObjFaninNum(pObj) > 1 ? Vec_IntEntryP( vBits, Wlc_ObjCopy(p, Wlc_ObjFaninId1(pObj)) ) : NULL;
         pFans2  = Wlc_ObjFaninNum(pObj) > 2 ? Vec_IntEntryP( vBits, Wlc_ObjCopy(p, Wlc_ObjFaninId2(pObj)) ) : NULL;
+        pFans3  = Wlc_ObjFaninNum(pObj) > 3 ? Vec_IntEntryP( vBits, Wlc_ObjCopy(p, Wlc_ObjFaninId(pObj,3)) ) : NULL;
         Vec_IntClear( vRes );
         assert( nRange > 0 );
         if ( pPar->vBoxIds && pObj->Mark )
@@ -1280,7 +1282,7 @@ Gia_Man_t * Wlc_NtkBitBlast( Wlc_Ntk_t * p, Wlc_BstPar_t * pParIn )
                 if ( pObj->Type == WLC_OBJ_ARI_ADD )
                     Wlc_BlastAdder( pExtra, pArg0, pArg1, nRange, CarryIn ); // result is in pFan0 (vRes)
                 else 
-                    Wlc_BlastSubtract( pExtra, pArg0, pArg1, nRange ); // result is in pFan0 (vRes)
+                    Wlc_BlastSubtract( pExtra, pArg0, pArg1, nRange, 1 ); // result is in pFan0 (vRes)
                 Vec_IntShrink( vRes, nRange );
             }
             else if ( fUseOldMultiplierBlasting )
@@ -1636,9 +1638,23 @@ Gia_Man_t * Wlc_NtkBitBlast( Wlc_Ntk_t * p, Wlc_BstPar_t * pParIn )
                     Wlc_BlastAdder( pNew, pArg0, pArg1, nRangeMax, CarryIn ); // result is in pFan0 (vRes)
             }
             else 
-                Wlc_BlastSubtract( pNew, pArg0, pArg1, nRange ); // result is in pFan0 (vRes)
+                Wlc_BlastSubtract( pNew, pArg0, pArg1, nRange, 1 ); // result is in pFan0 (vRes)
             Vec_IntShrink( vRes, nRange );
         }
+        else if ( pObj->Type == WLC_OBJ_ARI_ADDSUB ) 
+        {
+            int nRangeMax = Abc_MaxInt( nRange, Abc_MaxInt(nRange2, nRange3) );
+            int * pArg0 = Wlc_VecLoadFanins( vTemp0, pFans2, nRange2, nRangeMax, Wlc_ObjIsSignedFanin01(p, pObj) );
+            int * pArg1 = Wlc_VecLoadFanins( vTemp1, pFans2, nRange2, nRangeMax, Wlc_ObjIsSignedFanin01(p, pObj) );
+            int * pArg2 = Wlc_VecLoadFanins( vTemp2, pFans3, nRange3, nRangeMax, Wlc_ObjIsSignedFanin01(p, pObj) );
+            int ModeIn   = pFans0[0];
+            int CarryIn  = pFans1[0]; int j;
+            Wlc_BlastAdder   ( pNew, pArg0, pArg2, nRangeMax, CarryIn ); // result is in pArg0 (vTemp0)
+            Wlc_BlastSubtract( pNew, pArg1, pArg2, nRangeMax, Abc_LitNot(CarryIn) ); // result is in pArg1 (vTemp1)
+            Vec_IntClear( vRes );
+            for ( j = 0; j < nRange; j++ )
+                Vec_IntPush( vRes, Gia_ManHashMux(pNew, ModeIn, pArg0[j], pArg1[j]) ); 
+        }
         else if ( pObj->Type == WLC_OBJ_ARI_MULTI )
         {
             if ( fUseOldMultiplierBlasting )
diff --git a/src/base/wlc/wlcWriteVer.c b/src/base/wlc/wlcWriteVer.c
index a7d29187..45ce31e4 100644
--- a/src/base/wlc/wlcWriteVer.c
+++ b/src/base/wlc/wlcWriteVer.c
@@ -318,6 +318,20 @@ void Wlc_WriteVerInt( FILE * pFile, Wlc_Ntk_t * p, int fNoFlops )
             fprintf( pFile, " } ;\n" );
             continue;
         }
+        else if ( pObj->Type == WLC_OBJ_ARI_ADDSUB )
+        {
+            // out = mode ? a+b+cin : a-b-cin
+            int nRange = Wlc_ObjRange(Wlc_ObjFanin0(p, pObj));
+            fprintf( pFile, "%s ;\n", Wlc_ObjName(p, i) );
+            fprintf( pFile, "         " );
+            fprintf( pFile, "assign " );
+            fprintf( pFile, "%s = %s ? %s + %s + %s : %s - %s - %s ;\n", 
+                        Wlc_ObjName(p, i), Wlc_ObjName(p, Wlc_ObjFaninId0(pObj)),
+                        Wlc_ObjName(p, Wlc_ObjFaninId2(pObj)), Wlc_ObjName(p, Wlc_ObjFaninId(pObj,3)), Wlc_ObjName(p, Wlc_ObjFaninId1(pObj)),
+                        Wlc_ObjName(p, Wlc_ObjFaninId2(pObj)), Wlc_ObjName(p, Wlc_ObjFaninId(pObj,3)), Wlc_ObjName(p, Wlc_ObjFaninId1(pObj)) 
+                   );
+            continue;
+        }
         else if ( pObj->Type == WLC_OBJ_READ || pObj->Type == WLC_OBJ_WRITE )
         {
             if ( p->fMemPorts )