Resubstitution code.

2 files changed, 293 insertions, 0 deletions

diff --git a/src/aig/gia/giaResub.c b/src/aig/gia/giaResub.c
new file mode 100644
index 00000000..4b196fa4
--- /dev/null
+++ b/src/aig/gia/giaResub.c
@@ -0,0 +1,292 @@
+/**CFile****************************************************************
+
+  FileName    [giaResub.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Scalable AIG package.]
+
+  Synopsis    [Resubstitution.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: giaResub.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+#include "misc/vec/vecWec.h"
+#include "misc/vec/vecQue.h"
+#include "misc/vec/vecHsh.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Computes MFFCs of all qualifying nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Gia_ObjCheckMffc_rec( Gia_Man_t * p,Gia_Obj_t * pObj, int Limit, Vec_Int_t * vNodes )
+{
+    int iFanin;
+    if ( Gia_ObjIsCi(pObj) )
+        return 1;
+    assert( Gia_ObjIsAnd(pObj) );
+    iFanin = Gia_ObjFaninId0p(p, pObj);
+    Vec_IntPush( vNodes, iFanin );
+    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin0(pObj), Limit, vNodes)) )
+        return 0;
+    iFanin = Gia_ObjFaninId1p(p, pObj);
+    Vec_IntPush( vNodes, iFanin );
+    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin1(pObj), Limit, vNodes)) )
+        return 0;
+    if ( !Gia_ObjIsMux(p, pObj) )
+        return 1;
+    iFanin = Gia_ObjFaninId2p(p, pObj);
+    Vec_IntPush( vNodes, iFanin );
+    if ( !Gia_ObjRefDecId(p, iFanin) && (Vec_IntSize(vNodes) > Limit || !Gia_ObjCheckMffc_rec(p, Gia_ObjFanin2(p, pObj), Limit, vNodes)) )
+        return 0;
+    return 1;
+}
+static inline int Gia_ObjCheckMffc( Gia_Man_t * p, Gia_Obj_t * pRoot, int Limit, Vec_Int_t * vNodes, Vec_Int_t * vLeaves, Vec_Int_t * vInners )
+{
+    int RetValue, iObj, i;
+    Vec_IntClear( vNodes );
+    RetValue = Gia_ObjCheckMffc_rec( p, pRoot, Limit, vNodes );
+    if ( RetValue )
+    {
+        Vec_IntClear( vLeaves );
+        Vec_IntClear( vInners );
+        Vec_IntSort( vNodes, 0 );
+        Vec_IntForEachEntry( vNodes, iObj, i )
+            if ( Gia_ObjRefNumId(p, iObj) > 0 || Gia_ObjIsCi(Gia_ManObj(p, iObj)) )
+            {
+                if ( !Vec_IntSize(vLeaves) || Vec_IntEntryLast(vLeaves) != iObj )
+                    Vec_IntPush( vLeaves, iObj );
+            }
+            else
+            {
+                if ( !Vec_IntSize(vInners) || Vec_IntEntryLast(vInners) != iObj )
+                    Vec_IntPush( vInners, iObj );
+            }
+        Vec_IntPush( vInners, Gia_ObjId(p, pRoot) );
+    }
+    Vec_IntForEachEntry( vNodes, iObj, i )
+        Gia_ObjRefIncId( p, iObj );
+    return RetValue;
+}
+Vec_Wec_t * Gia_ManComputeMffcs( Gia_Man_t * p, int LimitMin, int LimitMax, int SuppMax, int RatioBest )
+{
+    Gia_Obj_t * pObj;
+    Vec_Wec_t * vMffcs;
+    Vec_Int_t * vNodes, * vLeaves, * vInners, * vMffc;
+    int i, iPivot;
+    assert( p->pMuxes );
+    vNodes  = Vec_IntAlloc( 2 * LimitMax );
+    vLeaves = Vec_IntAlloc( 2 * LimitMax );
+    vInners = Vec_IntAlloc( 2 * LimitMax );
+    vMffcs  = Vec_WecAlloc( 1000 );
+    Gia_ManCreateRefs( p );
+    Gia_ManForEachAnd( p, pObj, i )
+    {
+        if ( !Gia_ObjRefNum(p, pObj) )
+            continue;
+        if ( !Gia_ObjCheckMffc(p, pObj, LimitMax, vNodes, vLeaves, vInners) )
+            continue;
+        if ( Vec_IntSize(vInners) < LimitMin )
+            continue;
+        if ( Vec_IntSize(vLeaves) > SuppMax )
+            continue;
+        // improve cut
+        // collect cut
+        vMffc = Vec_WecPushLevel( vMffcs );
+        Vec_IntGrow( vMffc, Vec_IntSize(vLeaves) + Vec_IntSize(vInners) + 20 );
+        Vec_IntPush( vMffc, i );
+        Vec_IntPush( vMffc, Vec_IntSize(vLeaves) );
+        Vec_IntPush( vMffc, Vec_IntSize(vInners) );
+        Vec_IntAppend( vMffc, vLeaves );
+//        Vec_IntAppend( vMffc, vInners );
+        // add last entry equal to the ratio
+        Vec_IntPush( vMffc, 1000 * Vec_IntSize(vInners) / Vec_IntSize(vLeaves) );
+    }
+    Vec_IntFree( vNodes );
+    Vec_IntFree( vLeaves );
+    Vec_IntFree( vInners );
+    // sort MFFCs by their inner/leaf ratio
+    Vec_WecSortByLastInt( vMffcs, 1 );
+    Vec_WecForEachLevel( vMffcs, vMffc, i )
+        Vec_IntPop( vMffc );
+    // remove those whose ratio is not good
+    iPivot = RatioBest * Vec_WecSize(vMffcs) / 100;
+    Vec_WecForEachLevelStart( vMffcs, vMffc, i, iPivot )
+        Vec_IntErase( vMffc );
+    assert( iPivot <= Vec_WecSize(vMffcs) );
+    Vec_WecShrink( vMffcs, iPivot );
+    return vMffcs;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManPrintDivStats( Gia_Man_t * p, Vec_Wec_t * vMffcs, Vec_Wec_t * vPivots ) 
+{
+    int fVerbose = 0;
+    Vec_Int_t * vMffc;
+    int i, nDivs, nDivsAll = 0, nDivs0 = 0;
+    Vec_WecForEachLevel( vMffcs, vMffc, i )
+    {
+        nDivs = Vec_IntSize(vMffc) - 3 - Vec_IntEntry(vMffc, 1) - Vec_IntEntry(vMffc, 2);
+        nDivs0 += (nDivs == 0);
+        nDivsAll += nDivs;
+        if ( !fVerbose )
+            continue;
+        printf( "%6d : ",      Vec_IntEntry(vMffc, 0) );
+        printf( "Leaf =%3d  ", Vec_IntEntry(vMffc, 1) );
+        printf( "Mffc =%4d  ", Vec_IntEntry(vMffc, 2) );
+        printf( "Divs =%4d  ", nDivs );
+        printf( "\n" );
+    }
+    printf( "Collected %d (%.1f %%) MFFCs and %d (%.1f %%) have no divisors (div ave for others is %.2f).\n", 
+        Vec_WecSize(vMffcs), 100.0 * Vec_WecSize(vMffcs) / Gia_ManAndNum(p), 
+        nDivs0, 100.0 * nDivs0 / Gia_ManAndNum(p), 
+        1.0*nDivsAll/Abc_MaxInt(1, Vec_WecSize(vMffcs) - nDivs0) );
+    printf( "Using %.2f MB for MFFCs and %.2f MB for pivots.   ", 
+        Vec_WecMemory(vMffcs)/(1<<20), Vec_WecMemory(vPivots)/(1<<20) );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Compute divisors and Boolean functions for the nodes.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManAddDivisors( Gia_Man_t * p, Vec_Wec_t * vMffcs )
+{
+    Vec_Wec_t * vPivots;
+    Vec_Int_t * vMffc, * vPivot, * vPivot0, * vPivot1;
+    Vec_Int_t * vCommon, * vCommon2, * vMap;
+    Gia_Obj_t * pObj;
+    int i, k, iObj, iPivot, iMffc;
+//abctime clkStart = Abc_Clock();
+    // initialize pivots (mapping of nodes into MFFCs whose leaves they are)
+    vMap = Vec_IntStartFull( Gia_ManObjNum(p) );
+    vPivots = Vec_WecStart( Gia_ManObjNum(p) );
+    Vec_WecForEachLevel( vMffcs, vMffc, i )
+    {
+        assert( Vec_IntSize(vMffc) == 3 + Vec_IntEntry(vMffc, 1) );
+        iPivot = Vec_IntEntry( vMffc, 0 );
+        Vec_IntWriteEntry( vMap, iPivot, i );
+        // iterate through the MFFC leaves
+        Vec_IntForEachEntryStart( vMffc, iObj, k, 3 )
+        {
+            vPivot = Vec_WecEntry( vPivots, iObj );
+            if ( Vec_IntSize(vPivot) == 0 )
+                Vec_IntGrow(vPivot, 4);
+            Vec_IntPush( vPivot, iPivot );            
+        }
+    }
+    Vec_WecForEachLevel( vPivots, vPivot, i )
+        Vec_IntSort( vPivot, 0 );
+    // create pivots for internal nodes while growing MFFCs
+    vCommon = Vec_IntAlloc( 100 );
+    vCommon2 = Vec_IntAlloc( 100 );
+    Gia_ManForEachAnd( p, pObj, i )
+    {
+        // find commont pivots
+        // the slow down happens because some PIs have very large sets of pivots
+        vPivot0 = Vec_WecEntry( vPivots, Gia_ObjFaninId0(pObj, i) );
+        vPivot1 = Vec_WecEntry( vPivots, Gia_ObjFaninId1(pObj, i) );
+        Vec_IntTwoFindCommon( vPivot0, vPivot1, vCommon );
+        if ( Gia_ObjIsMuxId(p, i) )
+        {
+            vPivot = Vec_WecEntry( vPivots, Gia_ObjFaninId2(p, i) );
+            Vec_IntTwoFindCommon( vPivot, vCommon, vCommon2 );
+            ABC_SWAP( Vec_Int_t *, vCommon, vCommon2 );
+        }
+        if ( Vec_IntSize(vCommon) == 0 )
+            continue;
+        // add new pivots (this trick increased memory used in vPivots)
+        vPivot = Vec_WecEntry( vPivots, i );
+        Vec_IntTwoMerge2( vPivot, vCommon, vCommon2 );
+        ABC_SWAP( Vec_Int_t, *vPivot, *vCommon2 );
+        // grow MFFCs
+        Vec_IntForEachEntry( vCommon, iObj, k )
+        {
+            iMffc = Vec_IntEntry( vMap, iObj );
+            assert( iMffc != -1 );
+            vMffc = Vec_WecEntry( vMffcs, iMffc );
+            Vec_IntPush( vMffc, i );
+        }
+    }
+//Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
+    Vec_IntFree( vCommon );
+    Vec_IntFree( vCommon2 );
+    Vec_IntFree( vMap );
+    Gia_ManPrintDivStats( p, vMffcs, vPivots );
+    Vec_WecFree( vPivots );
+    // returns the modified array of MFFCs
+}
+void Gia_ManResubTest( Gia_Man_t * p )
+{
+    Vec_Wec_t * vMffcs;
+    Gia_Man_t * pNew = Gia_ManDupMuxes( p );
+abctime clkStart = Abc_Clock();
+    vMffcs = Gia_ManComputeMffcs( pNew, 4, 100, 8, 100 );
+    Gia_ManAddDivisors( pNew, vMffcs );
+    Vec_WecFree( vMffcs );
+Abc_PrintTime( 1, "Time", Abc_Clock() - clkStart );
+    Gia_ManStop( pNew );
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Perform resubstitution.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/aig/gia/module.make b/src/aig/gia/module.make
index ec9a2bcd..4b5c31c2 100644
--- a/src/aig/gia/module.make
+++ b/src/aig/gia/module.make
@@ -35,6 +35,7 @@ SRC +=    src/aig/gia/giaAig.c \
     src/aig/gia/giaMini.c \
     src/aig/gia/giaMuxes.c \
     src/aig/gia/giaPat.c \
+    src/aig/gia/giaResub.c \
     src/aig/gia/giaRetime.c \
     src/aig/gia/giaScl.c \
     src/aig/gia/giaShrink.c \