Enabling additional matching feature in the LUT mapper.

11 files changed, 586 insertions, 8 deletions

diff --git a/abclib.dsp b/abclib.dsp
index b0c8616b..79aaf496 100644
--- a/abclib.dsp
+++ b/abclib.dsp
@@ -2299,6 +2299,10 @@ SOURCE=.\src\map\if\ifDec16.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\src\map\if\ifDec75.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\src\map\if\ifLibBox.c
 # End Source File
 # Begin Source File
diff --git a/src/aig/gia/giaIf.c b/src/aig/gia/giaIf.c
index 278381cb..583e178a 100644
--- a/src/aig/gia/giaIf.c
+++ b/src/aig/gia/giaIf.c
@@ -235,6 +235,34 @@ void Gia_ManPrintMappingStats( Gia_Man_t * p )
     Abc_Print( 1, "lev =%5d  ", LevelMax );
     Abc_Print( 1, "mem =%5.2f MB", 4.0*(Gia_ManObjNum(p) + 2*nLuts + nFanins)/(1<<20) );
     Abc_Print( 1, "\n" );
+
+    {
+        char * pFileName = "stats_map.txt";
+        static char FileNameOld[1000] = {0};
+        static int nNodesOld, nAreaOld, nDelayOld;
+        static abctime clk = 0;
+        FILE * pTable = fopen( pFileName, "a+" );
+        if ( strcmp( FileNameOld, p->pName ) )
+        {
+            sprintf( FileNameOld, "%s", p->pName );
+            fprintf( pTable, "\n" );
+            fprintf( pTable, "%s  ", p->pName );
+            fprintf( pTable, "%d ", Gia_ManCiNum(p) );
+            fprintf( pTable, "%d ", Gia_ManCoNum(p) );
+            fprintf( pTable, "%d  ", Gia_ManAndNum(p) );
+            fprintf( pTable, "%d ", nLuts           );
+            fprintf( pTable, "%d ", LevelMax        );
+            clk = Abc_Clock();
+        }
+        else
+        {
+            fprintf( pTable, " " );
+            fprintf( pTable, "%d ", nLuts           );
+            fprintf( pTable, "%d ", LevelMax        );
+//            fprintf( pTable, "%.2f", 1.0*(Abc_Clock() - clk)/CLOCKS_PER_SEC );
+        }
+        fclose( pTable );
+    }
 }
 
 /**Function*************************************************************
@@ -344,6 +372,7 @@ void Gia_ManChoiceLevel_rec( Gia_Man_t * p, Gia_Obj_t * pObj )
         if ( LevelMax < Gia_ObjLevel(p, pNext) )
             LevelMax = Gia_ObjLevel(p, pNext);
         LevelMax++;
+        assert( LevelMax > 0 );
 
         // get the level of the nodes in the choice node
         if ( (pNext = Gia_ObjSiblObj(p, Gia_ObjId(p, pObj))) )
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index e48886be..399183ab 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -29192,7 +29192,7 @@ int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
     }
     pPars->pLutLib = (If_LibLut_t *)pAbc->pLibLut;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "KCFAGDEWSqaflepmrsdbgyojikczvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "KCFAGDEWSqalepmrsdbgyojikfuczvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -29309,9 +29309,6 @@ int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'r':
             pPars->fExpRed ^= 1;
             break;
-        case 'f':
-            pPars->fFancy ^= 1;
-            break;
         case 'l':
             pPars->fLatchPaths ^= 1;
             break;
@@ -29351,6 +29348,12 @@ int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'k':
             pPars->fEnableCheck10 ^= 1;
             break;
+        case 'f':
+            pPars->fEnableCheck75 ^= 1;
+            break;
+        case 'u':
+            pPars->fEnableCheck75u ^= 1;
+            break;
         case 'c':
             pPars->fEnableRealPos ^= 1;
             break;
@@ -29416,7 +29419,7 @@ int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
         pPars->fCutMin = 1;
     }
 
-    if ( pPars->fEnableCheck07 + pPars->fEnableCheck08 + pPars->fEnableCheck10 + (pPars->pLutStruct != NULL) > 1 )
+    if ( pPars->fEnableCheck07 + pPars->fEnableCheck08 + pPars->fEnableCheck10 + pPars->fEnableCheck75 + pPars->fEnableCheck75u + (pPars->pLutStruct != NULL) > 1 )
     {
         Abc_Print( -1, "Only one additional check can be performed at the same time.\n" );
         return 1;
@@ -29451,6 +29454,26 @@ int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
         pPars->pFuncCell = If_CutPerformCheck10;
         pPars->fCutMin = 1;
     }
+    if ( pPars->fEnableCheck75 )
+    {
+        if ( pPars->nLutSize < 6 || pPars->nLutSize > 8 )
+        {
+            Abc_Print( -1, "This feature only works for {6,7,8}-LUTs.\n" );
+            return 1;
+        }
+        pPars->pFuncCell = If_CutPerformCheck75;
+        pPars->fCutMin = 1;
+    }
+    if ( pPars->fEnableCheck75u )
+    {
+        if ( pPars->nLutSize < 6 || pPars->nLutSize > 8 )
+        {
+            Abc_Print( -1, "This feature only works for {6,7,8}-LUTs.\n" );
+            return 1;
+        }
+        pPars->pFuncCell = If_CutPerformCheck75;
+        pPars->fCutMin = 1;
+    }
     if ( pPars->pLutStruct )
     {
         if ( pPars->nLutSize < 6 || pPars->nLutSize > 16 )
@@ -29536,7 +29559,7 @@ usage:
         sprintf(LutSize, "library" );
     else
         sprintf(LutSize, "%d", pPars->nLutSize );
-    Abc_Print( -2, "usage: &if [-KCFAG num] [-DEW float] [-S str] [-qarlepmsdbgyojikczvh]\n" );
+    Abc_Print( -2, "usage: &if [-KCFAG num] [-DEW float] [-S str] [-qarlepmsdbgyojikfuczvh]\n" );
     Abc_Print( -2, "\t           performs FPGA technology mapping of the network\n" );
     Abc_Print( -2, "\t-K num   : the number of LUT inputs (2 < num < %d) [default = %s]\n", IF_MAX_LUTSIZE+1, LutSize );
     Abc_Print( -2, "\t-C num   : the max number of priority cuts (0 < num < 2^12) [default = %d]\n", pPars->nCutsMax );
@@ -29549,7 +29572,6 @@ usage:
     Abc_Print( -2, "\t-S str   : string representing the LUT structure [default = %s]\n", pPars->pLutStruct ? pPars->pLutStruct : "not used" );
     Abc_Print( -2, "\t-q       : toggles preprocessing using several starting points [default = %s]\n", pPars->fPreprocess? "yes": "no" );
     Abc_Print( -2, "\t-a       : toggles area-oriented mapping [default = %s]\n", pPars->fArea? "yes": "no" );
-//    Abc_Print( -2, "\t-f       : toggles one fancy feature [default = %s]\n", pPars->fFancy? "yes": "no" );
     Abc_Print( -2, "\t-r       : enables expansion/reduction of the best cuts [default = %s]\n", pPars->fExpRed? "yes": "no" );
     Abc_Print( -2, "\t-l       : optimizes latch paths for delay, other paths for area [default = %s]\n", pPars->fLatchPaths? "yes": "no" );
     Abc_Print( -2, "\t-e       : uses edge-based cut selection heuristics [default = %s]\n", pPars->fEdge? "yes": "no" );
@@ -29564,6 +29586,8 @@ usage:
     Abc_Print( -2, "\t-j       : toggles enabling additional check [default = %s]\n", pPars->fEnableCheck07? "yes": "no" );
     Abc_Print( -2, "\t-i       : toggles enabling additional check [default = %s]\n", pPars->fEnableCheck08? "yes": "no" );
     Abc_Print( -2, "\t-k       : toggles enabling additional check [default = %s]\n", pPars->fEnableCheck10? "yes": "no" );
+    Abc_Print( -2, "\t-f       : toggles enabling additional check [default = %s]\n", pPars->fEnableCheck75? "yes": "no" );
+    Abc_Print( -2, "\t-u       : toggles enabling additional check [default = %s]\n", pPars->fEnableCheck75u? "yes": "no" );
     Abc_Print( -2, "\t-c       : toggles enabling additional feature [default = %s]\n", pPars->fEnableRealPos? "yes": "no" );
     Abc_Print( -2, "\t-z       : toggles deriving LUTs when mapping into LUT structures [default = %s]\n", pPars->fDeriveLuts? "yes": "no" );
     Abc_Print( -2, "\t-v       : toggles verbose output [default = %s]\n", pPars->fVerbose? "yes": "no" );
diff --git a/src/map/if/if.h b/src/map/if/if.h
index be787a0b..5076bb28 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -117,6 +117,8 @@ struct If_Par_t_
     int                fEnableCheck07;// enable additional checking
     int                fEnableCheck08;// enable additional checking
     int                fEnableCheck10;// enable additional checking
+    int                fEnableCheck75;// enable additional checking
+    int                fEnableCheck75u;// enable additional checking
     int                fEnableRealPos;// enable additional feature
     int                fUseDsd;       // compute DSD of the cut functions
     int                fDeriveLuts;   // enables deriving LUT structures
@@ -492,6 +494,9 @@ extern int             If_CutPerformCheck07( If_Man_t * p, unsigned * pTruth, in
 extern int             If_CutPerformCheck08( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck10( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern int             If_CutPerformCheck16( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
+extern int             If_CutPerformCheck45( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
+extern int             If_CutPerformCheck54( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
+extern int             If_CutPerformCheck75( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr );
 extern float           If_CutDelayLutStruct( If_Man_t * p, If_Cut_t * pCut, char * pStr, float WireDelay );
 extern int             If_CluCheckExt( void * p, word * pTruth, int nVars, int nLutLeaf, int nLutRoot, 
                            char * pLut0, char * pLut1, word * pFunc0, word * pFunc1 );
diff --git a/src/map/if/ifCut.c b/src/map/if/ifCut.c
index 78f9ec68..c9edc66b 100644
--- a/src/map/if/ifCut.c
+++ b/src/map/if/ifCut.c
@@ -856,7 +856,7 @@ void If_CutSort( If_Man_t * p, If_Set_t * pCutSet, If_Cut_t * pCut )
         return;
     }
 
-    if ( (p->pPars->fUseDsd || p->pPars->fUseBat || p->pPars->fEnableCheck07 || p->pPars->fEnableCheck08 || p->pPars->fEnableCheck10 || p->pPars->pLutStruct || p->pPars->fUserRecLib) && !pCut->fUseless )
+    if ( (p->pPars->fUseDsd || p->pPars->fUseBat || p->pPars->fEnableCheck07 || p->pPars->fEnableCheck08 || p->pPars->fEnableCheck10 || p->pPars->fEnableCheck75 || p->pPars->fEnableCheck75u || p->pPars->pLutStruct || p->pPars->fUserRecLib) && !pCut->fUseless )
     {
         If_Cut_t * pFirst = pCutSet->ppCuts[0];
         if ( pFirst->fUseless || If_ManSortCompare(p, pFirst, pCut) == 1 )
diff --git a/src/map/if/ifDec07.c b/src/map/if/ifDec07.c
index 6d454a96..4c586ed8 100644
--- a/src/map/if/ifDec07.c
+++ b/src/map/if/ifDec07.c
@@ -455,10 +455,12 @@ word If_Dec7Perform( word t0[2], int fDerive )
     // start arrays
     for ( i = 0; i < 7; i++ )
     {
+/*
         if ( i < 6 )
             assert( If_Dec6HasVar( t[0], i ) || If_Dec6HasVar( t[1], i ) );
         else
             assert( t[0] != t[1] );
+*/
         Pla2Var[i] = Var2Pla[i] = i;
     }
     // generate permutations
diff --git a/src/map/if/ifDec16.c b/src/map/if/ifDec16.c
index e349f6eb..729b0489 100644
--- a/src/map/if/ifDec16.c
+++ b/src/map/if/ifDec16.c
@@ -1749,6 +1749,133 @@ If_Grp_t If_CluCheck( If_Man_t * p, word * pTruth0, int nVars, int iVarStart, in
     return G1;
 }
 
+
+static inline word Abc_Tt6Cofactor0( word t, int iVar )
+{
+    assert( iVar >= 0 && iVar < 6 );
+    return (t &~Truth6[iVar]) | ((t &~Truth6[iVar]) << (1<<iVar));
+}
+static inline word Abc_Tt6Cofactor1( word t, int iVar )
+{
+    assert( iVar >= 0 && iVar < 6 );
+    return (t & Truth6[iVar]) | ((t & Truth6[iVar]) >> (1<<iVar));
+}
+int If_CluCheckDecIn( word t, int nVars )
+{
+    int v, u, Cof2[2], Cof4[4];
+//    for ( v = 0; v < nVars; v++ )
+    for ( v = 0; v < 1; v++ ) // restrict to the first (decomposed) input
+    {
+        Cof2[0] = Abc_Tt6Cofactor0( t, v );
+        Cof2[1] = Abc_Tt6Cofactor1( t, v );
+        for ( u = v+1; u < nVars; u++ )
+        {
+            Cof4[0] = Abc_Tt6Cofactor0( Cof2[0], u );
+            Cof4[1] = Abc_Tt6Cofactor1( Cof2[0], u );
+            Cof4[2] = Abc_Tt6Cofactor0( Cof2[1], u );
+            Cof4[3] = Abc_Tt6Cofactor1( Cof2[1], u );
+            if ( Cof4[0] == Cof4[1] && Cof4[0] == Cof4[2] )
+                return 1;
+            if ( Cof4[0] == Cof4[2] && Cof4[0] == Cof4[3] )
+                return 1;
+            if ( Cof4[0] == Cof4[1] && Cof4[0] == Cof4[3] )
+                return 1;
+            if ( Cof4[1] == Cof4[2] && Cof4[1] == Cof4[3] )
+                return 1;
+        }
+    }
+    return 0;
+}
+int If_CluCheckDecInU( word t, int nVars )
+{
+    int v, u, Cof2[2], Cof4[4];
+//    for ( v = 0; v < nVars; v++ )
+    for ( v = 0; v < 1; v++ ) // restrict to the first (decomposed) input
+    {
+        Cof2[0] = Abc_Tt6Cofactor0( t, v );
+        Cof2[1] = Abc_Tt6Cofactor1( t, v );
+        for ( u = v+1; u < nVars; u++ )
+        {
+            Cof4[0] = Abc_Tt6Cofactor0( Cof2[0], u );
+            Cof4[1] = Abc_Tt6Cofactor1( Cof2[0], u );
+            Cof4[2] = Abc_Tt6Cofactor0( Cof2[1], u );
+            Cof4[3] = Abc_Tt6Cofactor1( Cof2[1], u );
+            if ( Cof4[0] == Cof4[1] && Cof4[0] == Cof4[2] )
+                return 1;
+            if ( Cof4[0] == Cof4[2] && Cof4[0] == Cof4[3] )
+                return 1;
+        }
+    }
+    return 0;
+}
+int If_CluCheckDecOut( word t, int nVars )
+{
+    int v;
+    for ( v = 0; v < nVars; v++ )
+        if ( 
+             (t & Truth6[v]) == 0   ||  //  F * !a
+             (~t & Truth6[v]) == 0  ||  // !F * !a
+             (t & ~Truth6[v]) == 0  ||  //  F *  a
+             (~t & ~Truth6[v]) == 0     // !F *  a   
+           )
+            return 1;
+    return 0;
+}
+int If_CluCheckDecOutU( word t, int nVars )
+{
+    int v;
+    for ( v = 0; v < nVars; v++ )
+        if ( 
+             (t & ~Truth6[v]) == 0  ||  //  F *  a
+             (~t & ~Truth6[v]) == 0     // !F *  a   
+           )
+            return 1;
+    return 0;
+}
+
+int If_CutPerformCheck45( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr )
+{    
+    // 5LUT -> 4LUT
+    If_Grp_t G, R;
+    word Func0, Func1;
+    G = If_CluCheck( p, (word *)pTruth, nLeaves, 0, 5, 4, &R, &Func0, &Func1, NULL, 0 );
+    if ( G.nVars == 0 )
+        return 0;
+    Func0 = If_CluAdjust( Func0, R.nVars );
+    Func1 = If_CluAdjust( Func1, G.nVars );
+#if 0
+    Kit_DsdPrintFromTruth( pTruth, nVars ); printf( "\n" );
+    Kit_DsdPrintFromTruth( (unsigned*)&Func0, R.nVars ); printf( "\n" );
+    Kit_DsdPrintFromTruth( (unsigned*)&Func1, G.nVars ); printf( "\n" );
+    If_CluPrintGroup( &R );
+    If_CluPrintGroup( &G );
+#endif
+    if ( G.nVars < 5 || (p->pPars->fEnableCheck75 && If_CluCheckDecOut(Func1, 5)) || (p->pPars->fEnableCheck75u && If_CluCheckDecOutU(Func1, 5)) )
+        return 1;
+    return 0;
+}
+int If_CutPerformCheck54( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr )
+{    
+    // 4LUT -> 5LUT
+    If_Grp_t G, R;
+    word Func0, Func1;
+    G = If_CluCheck( p, (word *)pTruth, nLeaves, 0, 4, 5, &R, &Func0, &Func1, NULL, 0 );
+    if ( G.nVars == 0 )
+        return 0;
+    Func0 = If_CluAdjust( Func0, R.nVars );
+    Func1 = If_CluAdjust( Func1, G.nVars );
+#if 0
+    Kit_DsdPrintFromTruth( pTruth, nVars ); printf( "\n" );
+    Kit_DsdPrintFromTruth( (unsigned*)&Func0, R.nVars ); printf( "\n" );
+    Kit_DsdPrintFromTruth( (unsigned*)&Func1, G.nVars ); printf( "\n" );
+    If_CluPrintGroup( &R );
+    If_CluPrintGroup( &G );
+#endif
+    if ( R.nVars < 5 || (p->pPars->fEnableCheck75 && If_CluCheckDecIn(Func0, 5)) || (p->pPars->fEnableCheck75u && If_CluCheckDecInU(Func0, 5)) )
+        return 1;
+    return 0;
+}
+
 // returns the best group found
 If_Grp_t If_CluCheck3( If_Man_t * p, word * pTruth0, int nVars, int nLutLeaf, int nLutLeaf2, int nLutRoot, 
                       If_Grp_t * pR, If_Grp_t * pG2, word * pFunc0, word * pFunc1, word * pFunc2 )
diff --git a/src/map/if/ifDec75.c b/src/map/if/ifDec75.c
new file mode 100644
index 00000000..0135f87d
--- /dev/null
+++ b/src/map/if/ifDec75.c
@@ -0,0 +1,341 @@
+/**CFile****************************************************************
+
+  FileName    [ifDec75.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [FPGA mapping based on priority cuts.]
+
+  Synopsis    [Performs additional check.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - November 21, 2006.]
+
+  Revision    [$Id: ifDec75.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "if.h"
+#include "misc/extra/extra.h"
+#include "bool/kit/kit.h"
+#include "opt/dau/dau.h"
+#include "misc/util/utilTruth.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Finds all boundsets for which decomposition exists.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Dau_DsdCheckDecExist_rec( char * pStr, char ** p, int * pMatches, int * pnSupp )
+{
+    if ( **p == '!' )
+        (*p)++;
+    while ( (**p >= 'A' && **p <= 'F') || (**p >= '0' && **p <= '9') )
+        (*p)++;
+    if ( **p >= 'a' && **p <= 'z' ) // var
+    {
+        (*pnSupp)++;
+        return 0;
+    }
+    if ( **p == '(' || **p == '[' ) // and/xor
+    {
+        unsigned Mask = 0;
+        int m, pSupps[8] = {0}, nParts = 0, nMints;
+        char * q = pStr + pMatches[ *p - pStr ];
+        assert( *q == **p + 1 + (**p != '(') );
+        for ( (*p)++; *p < q; (*p)++ )
+        {
+            Mask |= Dau_DsdCheckDecExist_rec( pStr, p, pMatches, &pSupps[nParts] );
+            *pnSupp += pSupps[nParts++];
+        }
+        assert( *p == q );
+        assert( nParts > 1 );
+        nMints = (1 << nParts);
+        for ( m = 1; m < nMints; m++ )
+        {
+            int i, Sum = 0;
+            for ( i = 0; i < nParts; i++ )
+                if ( (m >> i) & 1 )
+                    Sum += pSupps[i];
+            assert( Sum > 0 && Sum <= 8 );
+            if ( Sum >= 2 )
+                Mask |= (1 << Sum);
+        }
+        return Mask;
+    }
+    if ( **p == '<' || **p == '{' ) // mux
+    {
+        int uSupp;
+        unsigned Mask = 0;
+        char * q = pStr + pMatches[ *p - pStr ];
+        assert( *q == **p + 1 + (**p != '(') );
+        for ( (*p)++; *p < q; (*p)++ )
+        {
+            uSupp = 0;
+            Mask |= Dau_DsdCheckDecExist_rec( pStr, p, pMatches, &uSupp );
+            *pnSupp += uSupp;
+        }
+        assert( *p == q );
+        Mask |= (1 << *pnSupp);
+        return Mask;
+    }
+    assert( 0 );
+    return 0;
+}
+int Dau_DsdCheckDecExist( char * pDsd )
+{
+    int nSupp = 0;
+    if ( pDsd[1] == 0 )
+        return 0;
+    return Dau_DsdCheckDecExist_rec( pDsd, &pDsd, Dau_DsdComputeMatches(pDsd), &nSupp );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Finds all boundsets for which AND-decomposition exists.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Dau_DsdCheckDecAndExist_rec( char * pStr, char ** p, int * pMatches, int * pnSupp )
+{
+    if ( **p == '!' )
+        (*p)++;
+    while ( (**p >= 'A' && **p <= 'F') || (**p >= '0' && **p <= '9') )
+        (*p)++;
+    if ( **p >= 'a' && **p <= 'z' ) // var
+    {
+        (*pnSupp)++;
+        return 0;
+    }
+    if ( **p == '(' ) // and
+    {
+        unsigned Mask = 0;
+        int m, i, pSupps[8] = {0}, nParts = 0, nSimple = 0, nMints;
+        char * q = pStr + pMatches[ *p - pStr ];
+        assert( *q == **p + 1 + (**p != '(') );
+        for ( (*p)++; *p < q; (*p)++ )
+        {
+            Mask |= Dau_DsdCheckDecAndExist_rec( pStr, p, pMatches, &pSupps[nParts] );
+            nSimple += (pSupps[nParts] == 1);
+            *pnSupp += pSupps[nParts++];
+        }
+        assert( *p == q );
+        assert( nParts > 1 );
+        if ( nSimple > 0 )
+        {
+            nMints = (1 << nParts);
+            for ( m = 1; m < nMints; m++ )
+            {
+                int Sum = 0;
+                for ( i = 0; i < nParts; i++ )
+                    if ( pSupps[i] > 1 && ((m >> i) & 1) )
+                        Sum += pSupps[i];
+                assert( Sum <= 8 );
+                if ( Sum >= 2 )
+                    for ( i = 0; i < nSimple; i++ )
+                        Mask |= (1 << (Sum + i));
+            }
+            for ( i = 2; i < nSimple; i++ )
+                Mask |= (1 << i);
+        }
+        return Mask;
+    }
+    if ( **p == '<' || **p == '{' || **p == '[' ) // mux/xor/nondec
+    {
+        int uSupp;
+        unsigned Mask = 0;
+        char * q = pStr + pMatches[ *p - pStr ];
+        assert( *q == **p + 1 + (**p != '(') );
+        for ( (*p)++; *p < q; (*p)++ )
+        {
+            uSupp = 0;
+            Mask |= Dau_DsdCheckDecAndExist_rec( pStr, p, pMatches, &uSupp );
+            *pnSupp += uSupp;
+        }
+        assert( *p == q );
+        return Mask;
+    }
+    assert( 0 );
+    return 0;
+}
+int Dau_DsdCheckDecAndExist( char * pDsd )
+{
+    int nSupp = 0;
+    if ( pDsd[1] == 0 )
+        return 1;
+    return Dau_DsdCheckDecAndExist_rec( pDsd, &pDsd, Dau_DsdComputeMatches(pDsd), &nSupp );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs additional check.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int If_CutPerformCheck75__( If_Man_t * p, unsigned * pTruth, int nVars, int nLeaves, char * pStr )
+{
+    char pDsdStr[1000];
+    int fDerive = 0;
+    int nSizeNonDec, nDecExists, nDecAndExists;
+    static int Counter = 0;
+    Counter++;
+    if ( nLeaves < 6 )
+        return 1;
+    assert( nLeaves <= 8 );
+    if ( nLeaves < 8 && If_CutPerformCheck16( p, pTruth, nVars, nLeaves, "44" ) )
+        return 1;
+    // check decomposability
+    nSizeNonDec = Dau_DsdDecompose( (word *)pTruth, nLeaves, 0, 0, pDsdStr );
+//    printf( "Vars = %d  %s", nLeaves, pDsdStr );    printf( "\n" );
+//    Extra_PrintBinary( stdout, &nDecExists, 8 );    printf( "\n" );
+//    Extra_PrintBinary( stdout, &nDecAndExists, 8 ); printf( "\n" );
+    if ( nLeaves == 8 )
+    {
+        if ( nSizeNonDec >= 5 )
+            return 0;
+        nDecAndExists = Dau_DsdCheckDecAndExist( pDsdStr );
+        if ( nDecAndExists & 0x10 ) // bit 4
+            return 1;
+        else
+            return 0;
+    }
+    if ( nLeaves == 7 )
+    {
+        extern void If_Dec7MinimumBase( word uTruth[2], int * pSupp, int nVarsAll, int * pnVars );
+        word * pT = (word *)pTruth;
+        word pCof0[2], pCof1[2];
+        int v, nVarsMin;
+        if ( nSizeNonDec < 5 )
+        {
+            nDecExists = Dau_DsdCheckDecExist( pDsdStr );
+            if ( nDecExists & 0x10 ) // bit 4
+                return 1;
+            nDecAndExists = Dau_DsdCheckDecAndExist( pDsdStr );
+            if ( nDecAndExists & 0x18 ) // bit 4, 3
+                return 1;
+        }
+        // check cofactors
+        for ( v = 0; v < 7; v++ )
+        {
+            pCof0[0] = pCof1[0] = pT[0];
+            pCof0[1] = pCof1[1] = pT[1];
+            Abc_TtCofactor0( pCof0, 2, v );
+            Abc_TtCofactor1( pCof1, 2, v );
+            if ( Abc_TtSupportSize(pCof0, 7) < 4 )
+            {
+                If_Dec7MinimumBase( pCof1, NULL, 7, &nVarsMin );
+                nSizeNonDec = Dau_DsdDecompose( pCof1, nVarsMin, 0, 0, pDsdStr );
+                if ( nSizeNonDec >= 5 )
+                    continue;
+                nDecExists = Dau_DsdCheckDecExist( pDsdStr );
+                if ( nDecExists & 0x18 ) // bit 4, 3
+                    return 1;
+            }
+            else if ( Abc_TtSupportSize(pCof1, 7) < 4 )
+            {
+                If_Dec7MinimumBase( pCof0, NULL, 7, &nVarsMin );
+                nSizeNonDec = Dau_DsdDecompose( pCof0, nVarsMin, 0, 0, pDsdStr );
+                if ( nSizeNonDec >= 5 )
+                    continue;
+                nDecExists = Dau_DsdCheckDecExist( pDsdStr );
+                if ( nDecExists & 0x18 ) // bit 4, 3
+                    return 1;
+            }
+        }
+        return 0;
+    }
+    if ( nLeaves == 6 )
+    {
+        if ( nSizeNonDec < 5 )
+        {
+            nDecExists = Dau_DsdCheckDecExist( pDsdStr );
+            if ( nDecExists & 0x18 ) // bit 4, 3
+                return 1;
+            nDecAndExists = Dau_DsdCheckDecAndExist( pDsdStr );
+            if ( nDecAndExists & 0x1C ) // bit 4, 3, 2
+                return 1;
+        }
+        return If_CutPerformCheck07( p, pTruth, nVars, nLeaves, pStr );
+    }
+    assert( 0 );
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Performs additional check.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int If_CutPerformCheck75( If_Man_t * p, unsigned * pTruth0, int nVars, int nLeaves, char * pStr )
+{
+    word * pTruthW = (word *)pTruth0;
+    word pTruth[4] = { pTruthW[0], pTruthW[1], pTruthW[2], pTruthW[3] };
+    assert( nLeaves <= 8 );
+    Abc_TtMinimumBase( pTruth, NULL, nLeaves, &nLeaves );
+    if ( nLeaves < 6 )
+        return 1;
+//    if ( nLeaves < 8 && If_CutPerformCheck07( p, (unsigned *)pTruth, nVars, nLeaves, "44" ) )
+    if ( nLeaves < 8 && If_CutPerformCheck16( p, (unsigned *)pTruth, nVars, nLeaves, "44" ) )
+        return 1;
+    if ( p->pPars->fEnableCheck75 && nLeaves == 8 )
+    {
+//        char pDsdStr[1000] = "(!(abd)!(c!([fe][gh])))";
+        char pDsdStr[1000];
+        int nSizeNonDec = Dau_DsdDecompose( (word *)pTruth, nLeaves, 0, 0, pDsdStr );
+        if ( nSizeNonDec >= 5 )
+            return 0;
+        if ( Dau_DsdCheckDecAndExist(pDsdStr) & 0x10 ) // bit 4
+            return 1;
+        return 0;
+    }
+    if ( If_CutPerformCheck45( p, (unsigned *)pTruth, nVars, nLeaves, pStr ) )
+        return 1;
+    if ( If_CutPerformCheck54( p, (unsigned *)pTruth, nVars, nLeaves, pStr ) )
+        return 1;
+    return 0;
+}
+
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/map/if/module.make b/src/map/if/module.make
index b7b08722..e80aa1c4 100644
--- a/src/map/if/module.make
+++ b/src/map/if/module.make
@@ -5,6 +5,7 @@ SRC +=  src/map/if/ifCom.c \
     src/map/if/ifDec08.c \
     src/map/if/ifDec10.c \
     src/map/if/ifDec16.c \
+    src/map/if/ifDec75.c \
     src/map/if/ifLibBox.c \
     src/map/if/ifLibLut.c \
     src/map/if/ifMan.c \
diff --git a/src/misc/util/utilTruth.h b/src/misc/util/utilTruth.h
index 65b646fa..245a78fc 100644
--- a/src/misc/util/utilTruth.h
+++ b/src/misc/util/utilTruth.h
@@ -1067,6 +1067,50 @@ static inline void Abc_TtSwapVars( word * pTruth, int nVars, int iVar, int jVar
 
 /**Function*************************************************************
 
+  Synopsis    [Support minimization.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline void Abc_TtShrink( word * pF, int nVars, int nVarsAll, unsigned Phase )
+{
+    int i, k, Var = 0;
+    assert( nVarsAll <= 16 );
+    for ( i = 0; i < nVarsAll; i++ )
+        if ( Phase & (1 << i) )
+        {
+            for ( k = i-1; k >= Var; k-- )
+                Abc_TtSwapAdjacent( pF, Abc_TtWordNum(nVarsAll), k );
+            Var++;
+        }
+    assert( Var == nVars );
+}
+static inline int Abc_TtMinimumBase( word * t, int * pSupp, int nVarsAll, int * pnVars )
+{
+    int v, iVar = 0, uSupp = 0;
+    assert( nVarsAll <= 16 );
+    for ( v = 0; v < nVarsAll; v++ )
+        if ( Abc_TtHasVar( t, nVarsAll, v ) )
+        {
+            uSupp |= (1 << v);
+            if ( pSupp )
+                pSupp[iVar] = pSupp[v];
+            iVar++;
+        }
+    if ( pnVars )
+        *pnVars = iVar;
+    if ( uSupp == 0 || Abc_TtSuppIsMinBase( uSupp ) )
+        return 0;
+    Abc_TtShrink( t, iVar, nVarsAll, uSupp );
+    return 1;
+}
+
+/**Function*************************************************************
+
   Synopsis    [Implemeting given NPN config.]
 
   Description []
diff --git a/src/opt/dau/dau.h b/src/opt/dau/dau.h
index 070b894d..0f332b26 100644
--- a/src/opt/dau/dau.h
+++ b/src/opt/dau/dau.h
@@ -77,6 +77,7 @@ static inline int Dau_DsdReadVar( char * p )  { if ( *p == '!' ) p++; return *p
 /*=== dauCanon.c ==========================================================*/
 extern unsigned      Abc_TtCanonicize( word * pTruth, int nVars, char * pCanonPerm );
 /*=== dauDsd.c  ==========================================================*/
+extern int *         Dau_DsdComputeMatches( char * p );
 extern int           Dau_DsdDecompose( word * pTruth, int nVarsInit, int fSplitPrime, int fWriteTruth, char * pRes );
 extern void          Dau_DsdPrintFromTruth( FILE * pFile, word * pTruth, int nVarsInit );
 extern word *        Dau_DsdToTruth( char * p, int nVars );