Supporting AND-gate cuts in 'if' and '&if'

3 files changed, 27 insertions, 6 deletions

diff --git a/src/map/if/if.h b/src/map/if/if.h
index 067ce0ad..8616783b 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -55,7 +55,7 @@ ABC_NAMESPACE_HEADER_START
 // a very large number
 #define IF_INFINITY          100000000  
 // the largest possible user cut cost
-#define IF_COST_MAX          8191 // ((1<<13)-1)
+#define IF_COST_MAX          4095 // ((1<<12)-1)
 
 #define IF_BIG_CHAR ((char)120)
 
@@ -110,6 +110,8 @@ struct If_Par_t_
     float              Epsilon;       // value used in comparison floating point numbers
     int                nRelaxRatio;   // delay relaxation ratio
     int                nStructType;   // type of the structure
+    int                nAndDelay;     // delay of AND-gate in LUT library units
+    int                nAndArea;      // area of AND-gate in LUT library units
     int                fPreprocess;   // preprossing
     int                fArea;         // area-oriented mapping
     int                fFancy;        // a fancy feature
@@ -281,10 +283,11 @@ struct If_Cut_t_
     int                iCutFunc;      // TT ID of the cut
     int                uMaskFunc;     // polarity bitmask
     unsigned           uSign;         // cut signature
-    unsigned           Cost    : 13;  // the user's cost of the cut (related to IF_COST_MAX)
+    unsigned           Cost    : 12;  // the user's cost of the cut (related to IF_COST_MAX)
     unsigned           fCompl  :  1;  // the complemented attribute 
     unsigned           fUser   :  1;  // using the user's area and delay
-    unsigned           fUseless:  1;  // using the user's area and delay
+    unsigned           fUseless:  1;  // cannot be used in the mapping
+    unsigned           fAndCut :  1;  // matched with AND gate
     unsigned           nLimit  :  8;  // the maximum number of leaves
     unsigned           nLeaves :  8;  // the number of leaves
     int                pLeaves[0];
@@ -425,7 +428,7 @@ static inline int        If_CutDsdLit( If_Man_t * p, If_Cut_t * pCut )       { r
 static inline int        If_CutDsdIsCompl( If_Man_t * p, If_Cut_t * pCut )   { return Abc_LitIsCompl( If_CutDsdLit(p, pCut) );                                                     }
 static inline char *     If_CutDsdPerm( If_Man_t * p, If_Cut_t * pCut )      { return Vec_StrEntryP( p->vTtPerms[pCut->nLeaves], Abc_Lit2Var(pCut->iCutFunc) * Abc_MaxInt(6, pCut->nLeaves) );           }
 
-static inline float      If_CutLutArea( If_Man_t * p, If_Cut_t * pCut )      { return pCut->fUser? (float)pCut->Cost : (p->pPars->pLutLib? p->pPars->pLutLib->pLutAreas[pCut->nLeaves] : (float)1.0);    }
+static inline float      If_CutLutArea( If_Man_t * p, If_Cut_t * pCut )      { return pCut->fAndCut ? p->pPars->nAndArea : (pCut->fUser? (float)pCut->Cost : (p->pPars->pLutLib? p->pPars->pLutLib->pLutAreas[pCut->nLeaves] : (float)1.0));  }
 static inline float      If_CutLutDelay( If_LibLut_t * p, int Size, int iPin )  { return p ? (p->fVarPinDelays ? p->pLutDelays[Size][iPin] : p->pLutDelays[Size][0]) : 1.0;                              }
 
 
diff --git a/src/map/if/ifMap.c b/src/map/if/ifMap.c
index 89e94804..4f0372a6 100644
--- a/src/map/if/ifMap.c
+++ b/src/map/if/ifMap.c
@@ -100,6 +100,7 @@ void If_ObjPerformMappingAnd( If_Man_t * p, If_Obj_t * pObj, int Mode, int fPrep
     int fFunc0R, fFunc1R;
     int i, k, v, iCutDsd, fChange;
     int fSave0 = p->pPars->fDelayOpt || p->pPars->fDelayOptLut || p->pPars->fDsdBalance || p->pPars->fUserRecLib || p->pPars->fUseDsdTune || p->pPars->fUseCofVars || p->pPars->fUseAndVars || p->pPars->pLutStruct != NULL;
+    int fUseAndCut = (p->pPars->nAndDelay > 0) || (p->pPars->nAndArea > 0);
     assert( !If_ObjIsAnd(pObj->pFanin0) || pObj->pFanin0->pCutSet->nCuts > 0 );
     assert( !If_ObjIsAnd(pObj->pFanin1) || pObj->pFanin1->pCutSet->nCuts > 0 );
 
@@ -189,6 +190,10 @@ void If_ObjPerformMappingAnd( If_Man_t * p, If_Obj_t * pObj, int Mode, int fPrep
         // check if this cut is contained in any of the available cuts
         if ( !p->pPars->fSkipCutFilter && If_CutFilter( pCutSet, pCut, fSave0 ) )
             continue;
+        // check if the cut is a special AND-gate cut
+        pCut->fAndCut = fUseAndCut && pCut->nLeaves == 2 && pCut->pLeaves[0] == pObj->pFanin0->Id && pCut->pLeaves[1] == pObj->pFanin1->Id;
+        assert( pCut->nLeaves != 2 || pCut->pLeaves[0] < pCut->pLeaves[1] );
+        assert( pCut->nLeaves != 2 || pObj->pFanin0->Id < pObj->pFanin1->Id );
         // compute the truth table
         pCut->iCutFunc = -1;
         pCut->fCompl = 0;
diff --git a/src/map/if/ifTime.c b/src/map/if/ifTime.c
index 4211b385..c2ba40e8 100644
--- a/src/map/if/ifTime.c
+++ b/src/map/if/ifTime.c
@@ -98,7 +98,15 @@ float If_CutDelay( If_Man_t * p, If_Obj_t * pObj, If_Cut_t * pCut )
     float * pLutDelays;
     int i, Shift, Pin2PinDelay;//, iLeaf;
     Delay = -IF_FLOAT_LARGE;
-    if ( p->pPars->pLutLib )
+    if ( pCut->fAndCut )
+    {
+        If_CutForEachLeaf( p, pCut, pLeaf, i )
+        {
+            DelayCur = If_ObjCutBest(pLeaf)->Delay + p->pPars->nAndDelay;
+            Delay = IF_MAX( Delay, DelayCur );
+        }
+    }
+    else if ( p->pPars->pLutLib )
     {
         assert( !p->pPars->fLiftLeaves );
         pLutDelays = p->pPars->pLutLib->pLutDelays[pCut->nLeaves];
@@ -177,7 +185,12 @@ void If_CutPropagateRequired( If_Man_t * p, If_Obj_t * pObj, If_Cut_t * pCut, fl
     int i, Pin2PinDelay;//, iLeaf;
     assert( !p->pPars->fLiftLeaves );
     // compute the pins
-    if ( p->pPars->pLutLib )
+    if ( pCut->fAndCut )
+    {
+        If_CutForEachLeaf( p, pCut, pLeaf, i )
+            pLeaf->Required = IF_MIN( pLeaf->Required, ObjRequired - p->pPars->nAndDelay );
+    }
+    else if ( p->pPars->pLutLib )
     {
         pLutDelays = p->pPars->pLutLib->pLutDelays[pCut->nLeaves];
         if ( p->pPars->pLutLib->fVarPinDelays )