Detection of threshold functions.

9 files changed, 544 insertions, 65 deletions

diff --git a/src/aig/gia/giaIf.c b/src/aig/gia/giaIf.c
index a5eafb5f..131dfd11 100644
--- a/src/aig/gia/giaIf.c
+++ b/src/aig/gia/giaIf.c
@@ -366,15 +366,16 @@ void Gia_ManPrintGetMuxFanins( Gia_Man_t * p, Gia_Obj_t * pObj, int * pFanins )
     pFanins[1] = Gia_ObjId(p, Gia_Regular(pData1));
     pFanins[2] = Gia_ObjId(p, Gia_Regular(pData0));
 }
-int Gia_ManCountDupLut6( Gia_Man_t * p )
+int Gia_ManCountDupLut( Gia_Man_t * p )
 {
     int i, nCountDup = 0, nCountPis = 0, nCountMux = 0;
     Gia_ManCleanMark01( p );
     Gia_ManForEachLut( p, i )
-        if ( Gia_ObjLutSize(p, i) == 3 && Gia_ObjLutIsMux(p, i) )
+        if ( Gia_ObjLutIsMux(p, i) )
         {
             Gia_Obj_t * pFanin;
             int pFanins[3];
+            assert( Gia_ObjLutSize(p, i) == 2 || Gia_ObjLutSize(p, i) == 3 );
             Gia_ManPrintGetMuxFanins( p, Gia_ManObj(p, i), pFanins );
             Gia_ManObj(p, i)->fMark1 = 1;
 
@@ -401,21 +402,22 @@ void Gia_ManPrintMappingStats( Gia_Man_t * p, char * pDumpFile )
 {
     Gia_Obj_t * pObj;
     int * pLevels;
-    int i, k, iFan, nLutSize = 0, nLuts = 0, nFanins = 0, LevelMax = 0, Ave = 0, nMuxF7 = 0;
+    int i, k, iFan, nLutSize = 0, nLuts = 0, nFanins = 0, LevelMax = 0, Ave = 0, nMuxF = 0;
     if ( !Gia_ManHasMapping(p) )
         return;
     pLevels = ABC_CALLOC( int, Gia_ManObjNum(p) );
     Gia_ManForEachLut( p, i )
     {
-        if ( Gia_ObjLutSize(p, i) == 3 && Gia_ObjLutIsMux(p, i) )
+        if ( Gia_ObjLutIsMux(p, i) )
         {
             int pFanins[3];
+            assert( Gia_ObjLutSize(p, i) == 2 || Gia_ObjLutSize(p, i) == 3 );
             Gia_ManPrintGetMuxFanins( p, Gia_ManObj(p, i), pFanins );
             pLevels[i] = Abc_MaxInt( pLevels[i], pLevels[pFanins[0]]+1 );
             pLevels[i] = Abc_MaxInt( pLevels[i], pLevels[pFanins[1]] );
             pLevels[i] = Abc_MaxInt( pLevels[i], pLevels[pFanins[2]] );
             LevelMax = Abc_MaxInt( LevelMax, pLevels[i] );
-            nMuxF7++;
+            nMuxF++;
             nFanins++;
             continue;
         }
@@ -437,8 +439,8 @@ void Gia_ManPrintMappingStats( Gia_Man_t * p, char * pDumpFile )
     Abc_Print( 1, "Mapping (K=%d)  :  ", nLutSize );
     SetConsoleTextAttribute( hConsole, 14 ); // yellow
     Abc_Print( 1, "lut =%7d  ",  nLuts );
-    if ( nMuxF7 )
-    Abc_Print( 1, "mux =%7d  ",  nMuxF7 );
+    if ( nMuxF )
+    Abc_Print( 1, "muxF =%7d  ",  nMuxF );
     SetConsoleTextAttribute( hConsole, 10 ); // green
     Abc_Print( 1, "edge =%8d  ", nFanins );
     SetConsoleTextAttribute( hConsole, 12 ); // red
@@ -464,8 +466,8 @@ void Gia_ManPrintMappingStats( Gia_Man_t * p, char * pDumpFile )
     Abc_Print( 1, "\n" );
 #endif
 
-    if ( nMuxF7 )
-        Gia_ManCountDupLut6( p );
+    if ( nMuxF )
+        Gia_ManCountDupLut( p );
 
     if ( pDumpFile )
     {
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index 15bfc76b..3408144a 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -16256,10 +16256,11 @@ usage:
 ***********************************************************************/
 int Abc_CommandDsdFilter( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
+    extern void Id_DsdManTuneThresh( If_DsdMan_t * p, int fUnate, int fThresh, int fVerbose );
     If_DsdMan_t * pDsd = (If_DsdMan_t *)Abc_FrameReadManDsd();
-    int c, nLimit = 0, nLutSize = -1, fCleanOccur = 0, fCleanMarks = 0, fVerbose = 0;
+    int c, nLimit = 0, nLutSize = -1, fCleanOccur = 0, fCleanMarks = 0, fInvMarks = 0, fUnate = 0, fThresh = 0, fVerbose = 0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "LKomvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "LKomiutvh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -16287,6 +16288,15 @@ int Abc_CommandDsdFilter( Abc_Frame_t * pAbc, int argc, char ** argv )
         case 'm':
             fCleanMarks ^= 1;
             break;
+        case 'i':
+            fInvMarks ^= 1;
+            break;
+        case 'u':
+            fUnate ^= 1;
+            break;
+        case 't':
+            fThresh ^= 1;
+            break;
         case 'v':
             fVerbose ^= 1;
             break;
@@ -16309,15 +16319,24 @@ int Abc_CommandDsdFilter( Abc_Frame_t * pAbc, int argc, char ** argv )
         If_DsdManCleanOccur( pDsd, fVerbose );
     if ( fCleanMarks )
         If_DsdManCleanMarks( pDsd, fVerbose );
+    if ( fInvMarks )
+        If_DsdManInvertMarks( pDsd, fVerbose );
+    if ( fUnate )
+        Id_DsdManTuneThresh( pDsd, 1, 0, fVerbose );
+    if ( fThresh )
+        Id_DsdManTuneThresh( pDsd, 0, 1, fVerbose );
     return 0;
 
 usage:
-    Abc_Print( -2, "usage: dsd_filter [-LK num] [-omvh]\n" );
+    Abc_Print( -2, "usage: dsd_filter [-LK num] [-omiutvh]\n" );
     Abc_Print( -2, "\t         filtering structured and modifying parameters of DSD manager\n" );
     Abc_Print( -2, "\t-L num : remove structures with fewer occurrences that this [default = %d]\n", nLimit );
     Abc_Print( -2, "\t-K num : new LUT size to set for the DSD manager [default = %d]\n",           nLutSize );
     Abc_Print( -2, "\t-o     : toggles cleaning occurrence counters [default = %s]\n",              fCleanOccur? "yes": "no" );
     Abc_Print( -2, "\t-m     : toggles cleaning matching marks [default = %s]\n",                   fCleanMarks? "yes": "no" );
+    Abc_Print( -2, "\t-i     : toggles inverting matching marks [default = %s]\n",                  fInvMarks? "yes": "no" );
+    Abc_Print( -2, "\t-u     : toggles marking unate functions [default = %s]\n",                   fUnate? "yes": "no" );
+    Abc_Print( -2, "\t-t     : toggles marking threshold functions [default = %s]\n",               fThresh? "yes": "no" );
     Abc_Print( -2, "\t-v     : toggles verbose output [default = %s]\n",                            fVerbose? "yes": "no" );
     Abc_Print( -2, "\t-h     : print the command usage\n");
     return 1;
diff --git a/src/base/abci/abcDec.c b/src/base/abci/abcDec.c
index 3ed73c26..5e4f848a 100644
--- a/src/base/abci/abcDec.c
+++ b/src/base/abci/abcDec.c
@@ -502,6 +502,9 @@ void Abc_TruthDecPerform( Abc_TtStore_t * p, int DecType, int fVerbose )
         vCover = Vec_IntAlloc( 1 << 16 );
         for ( i = 0; i < p->nFuncs; i++ )
         {
+//            extern int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover );
+//            Abc_IsopTest( p->pFuncs[i], p->nVars, vCover );
+//            continue;
             if ( fVerbose )
                 printf( "%7d : ", i );
             pSopStr = Kit_PlaFromTruthNew( (unsigned *)p->pFuncs[i], p->nVars, vCover, vStr );
diff --git a/src/map/if/if.h b/src/map/if/if.h
index 909a54ce..d77ac536 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -550,6 +550,7 @@ extern If_DsdMan_t *   If_DsdManLoad( char * pFileName );
 extern void            If_DsdManMerge( If_DsdMan_t * p, If_DsdMan_t * pNew );
 extern void            If_DsdManCleanOccur( If_DsdMan_t * p, int fVerbose );
 extern void            If_DsdManCleanMarks( If_DsdMan_t * p, int fVerbose );
+extern void            If_DsdManInvertMarks( If_DsdMan_t * p, int fVerbose );
 extern If_DsdMan_t *   If_DsdManFilter( If_DsdMan_t * p, int Limit );
 extern int             If_DsdManCompute( If_DsdMan_t * p, word * pTruth, int nLeaves, unsigned char * pPerm, char * pLutStruct );
 extern char *          If_DsdManFileName( If_DsdMan_t * p );
diff --git a/src/map/if/ifDsd.c b/src/map/if/ifDsd.c
index 90e30287..cfccc362 100644
--- a/src/map/if/ifDsd.c
+++ b/src/map/if/ifDsd.c
@@ -1230,6 +1230,15 @@ void If_DsdManCleanMarks( If_DsdMan_t * p, int fVerbose )
     If_DsdVecForEachObj( &p->vObjs, pObj, i )
         pObj->fMark = 0;
 }
+void If_DsdManInvertMarks( If_DsdMan_t * p, int fVerbose )
+{
+    If_DsdObj_t * pObj; 
+    int i;
+    ABC_FREE( p->pCellStr );
+    Vec_WrdFreeP( &p->vPerms );
+    If_DsdVecForEachObj( &p->vObjs, pObj, i )
+        pObj->fMark = !pObj->fMark;
+}
 void If_DsdManFilter_rec( If_DsdMan_t * pNew, If_DsdMan_t * p, int i, Vec_Int_t * vMap )
 {
     If_DsdObj_t * pObj;
@@ -2698,6 +2707,70 @@ void Id_DsdManTuneStr( If_DsdMan_t * p, char * pStruct, int nConfls, int nProcs,
 
 #endif // pthreads are used
 
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Id_DsdManTuneThresh( If_DsdMan_t * p, int fUnate, int fThresh, int fVerbose )
+{
+    extern int Extra_ThreshCheck( word * t, int nVars, int * pW );
+    int fVeryVerbose = 0;
+    int pW[16];
+    ProgressBar * pProgress = NULL;
+    If_DsdObj_t * pObj;
+    word * pTruth, Perm;
+    int i, nVars, Value;
+    abctime clk = Abc_Clock();
+    assert( fUnate != fThresh );
+    if ( p->nObjsPrev > 0 )
+        printf( "Starting the tuning process from object %d (out of %d).\n", p->nObjsPrev, Vec_PtrSize(&p->vObjs) );
+    // clean the attributes
+    If_DsdVecForEachObj( &p->vObjs, pObj, i )
+        if ( i >= p->nObjsPrev )
+            pObj->fMark = 0;
+    if ( p->vPerms == NULL )
+        p->vPerms = Vec_WrdStart( Vec_PtrSize(&p->vObjs) );
+    else
+        Vec_WrdFillExtra( p->vPerms, Vec_PtrSize(&p->vObjs), 0 );
+    pProgress = Extra_ProgressBarStart( stdout, Vec_PtrSize(&p->vObjs) );
+    If_DsdVecForEachObjStart( &p->vObjs, pObj, i, p->nObjsPrev )
+    {
+        if ( (i & 0xFF) == 0 )
+            Extra_ProgressBarUpdate( pProgress, i, NULL );
+        nVars = If_DsdObjSuppSize(pObj);
+        pTruth = If_DsdManComputeTruth( p, Abc_Var2Lit(i, 0), NULL );
+        if ( fVeryVerbose )
+            Dau_DsdPrintFromTruth( pTruth, nVars );
+        if ( fVerbose )
+            printf( "%6d : %2d ", i, nVars );
+        if ( fUnate )
+            Value = Abc_TtIsUnate( pTruth, nVars );
+        else if ( fThresh )
+            Value = Extra_ThreshCheck( pTruth, nVars, pW );
+        Perm = 0;
+        if ( fVeryVerbose )
+            printf( "\n" );
+        if ( Value )
+            If_DsdVecObjSetMark( &p->vObjs, i );
+        else
+            Vec_WrdWriteEntry( p->vPerms, i, Perm );
+    }
+    p->nObjsPrev = 0;
+    p->LutSize = 0;
+    Extra_ProgressBarStop( pProgress );
+    printf( "Finished matching %d functions. ", Vec_PtrSize(&p->vObjs) );
+    Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
+    if ( fVeryVerbose )
+        If_DsdManPrintDistrib( p );
+}
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////
diff --git a/src/misc/extra/extraUtilThresh.c b/src/misc/extra/extraUtilThresh.c
new file mode 100644
index 00000000..88752b7d
--- /dev/null
+++ b/src/misc/extra/extraUtilThresh.c
@@ -0,0 +1,333 @@
+/**CFile****************************************************************
+
+  FileName    [extraUtilThresh.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [extra]
+
+  Synopsis    [Dealing with threshold functions.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - October 7, 2014.]
+
+  Revision    [$Id: extraUtilThresh.c,v 1.0 2014/10/07 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "misc/vec/vec.h"
+#include "misc/util/utilTruth.h"
+
+ABC_NAMESPACE_IMPL_START
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Checks thresholdness of the function.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Extra_ThreshPrintChow( int Chow0, int * pChow, int nVars )
+{
+    int i;
+    for ( i = 0; i < nVars; i++ )
+        printf( "%d ", pChow[i] );
+    printf( "  %d\n", Chow0 );
+}
+int Extra_ThreshComputeChow( word * t, int nVars, int * pChow )
+{
+    int i, k, Chow0 = 0, nMints = (1 << nVars);
+    memset( pChow, 0, sizeof(int) * nVars );
+    // compute Chow coefs
+    for ( i = 0; i < nMints; i++ )
+        if ( Abc_TtGetBit(t, i) )
+            for ( Chow0++, k = 0; k < nVars; k++ )
+                if ( (i >> k) & 1 )
+                    pChow[k]++;
+    // compute modified Chow coefs
+    for ( k = 0; k < nVars; k++ )
+        pChow[k] = 2 * pChow[k] - Chow0;
+    return Chow0 - (1 << (nVars-1));
+}
+void Extra_ThreshSortByChow( word * t, int nVars, int * pChow )
+{
+    int i, nWords = Abc_TtWordNum(nVars);
+    while ( 1 )
+    {
+        int fChange = 0;
+        for ( i = 0; i < nVars - 1; i++ )
+        {
+            if ( pChow[i] >= pChow[i+1] )
+                continue;
+            ABC_SWAP( int, pChow[i], pChow[i+1] );
+            Abc_TtSwapAdjacent( t, nWords, i );
+            fChange = 1;
+        }
+        if ( !fChange )
+            return;
+    }
+}
+static inline int Extra_ThreshWeightedSum( int * pW, int nVars, int m )
+{
+    int i, Cost = 0;
+    for ( i = 0; i < nVars; i++ )
+        if ( (m >> i) & 1 )
+            Cost += pW[i];
+    return Cost;
+}
+int Extra_ThreshSelectWeights3( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars);
+    assert( nVars == 3 );
+    for ( pW[2] = 1;     pW[2] <= nVars; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= nVars; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= nVars; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+//            printf( "%c%d ", Abc_TtGetBit(t, m) ? '+' : '-', Extra_ThreshWeightedSum(pW, nVars, m) );
+        }
+//        printf( "  -%d +%d\n", Lmax, Lmin );
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights4( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars);
+    assert( nVars == 4 );
+    for ( pW[3] = 1;     pW[3] <= nVars; pW[3]++ )
+    for ( pW[2] = pW[3]; pW[2] <= nVars; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= nVars; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= nVars; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+        }
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights5( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars), Limit = nVars + 0;
+    assert( nVars == 5 );
+    for ( pW[4] = 1;     pW[4] <= Limit; pW[4]++ )
+    for ( pW[3] = pW[4]; pW[3] <= Limit; pW[3]++ )
+    for ( pW[2] = pW[3]; pW[2] <= Limit; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= Limit; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= Limit; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+        }
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights6( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars), Limit = nVars + 3;
+    assert( nVars == 6 );
+    for ( pW[5] = 1;     pW[5] <= Limit; pW[5]++ )
+    for ( pW[4] = pW[5]; pW[4] <= Limit; pW[4]++ )
+    for ( pW[3] = pW[4]; pW[3] <= Limit; pW[3]++ )
+    for ( pW[2] = pW[3]; pW[2] <= Limit; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= Limit; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= Limit; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+        }
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights7( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars), Limit = nVars + 6;
+    assert( nVars == 7 );
+    for ( pW[6] = 1;     pW[6] <= Limit; pW[6]++ )
+    for ( pW[5] = pW[6]; pW[5] <= Limit; pW[5]++ )
+    for ( pW[4] = pW[5]; pW[4] <= Limit; pW[4]++ )
+    for ( pW[3] = pW[4]; pW[3] <= Limit; pW[3]++ )
+    for ( pW[2] = pW[3]; pW[2] <= Limit; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= Limit; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= Limit; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+        }
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights8( word * t, int nVars, int * pW )
+{
+    int m, Lmin, Lmax, nMints = (1 << nVars), Limit = nVars + 1; // <<-- incomplete detection to save runtime!
+    assert( nVars == 8 );
+    for ( pW[7] = 1;     pW[7] <= Limit; pW[7]++ )
+    for ( pW[6] = pW[7]; pW[6] <= Limit; pW[6]++ )
+    for ( pW[5] = pW[6]; pW[5] <= Limit; pW[5]++ )
+    for ( pW[4] = pW[5]; pW[4] <= Limit; pW[4]++ )
+    for ( pW[3] = pW[4]; pW[3] <= Limit; pW[3]++ )
+    for ( pW[2] = pW[3]; pW[2] <= Limit; pW[2]++ )
+    for ( pW[1] = pW[2]; pW[1] <= Limit; pW[1]++ )
+    for ( pW[0] = pW[1]; pW[0] <= Limit; pW[0]++ )
+    {
+        Lmin = 10000; Lmax = 0;
+        for ( m = 0; m < nMints; m++ )
+        {
+            if ( Abc_TtGetBit(t, m) )
+                Lmin = Abc_MinInt( Lmin, Extra_ThreshWeightedSum(pW, nVars, m) );
+            else
+                Lmax = Abc_MaxInt( Lmax, Extra_ThreshWeightedSum(pW, nVars, m) );
+            if ( Lmax >= Lmin )
+                break;
+        }
+        if ( m < nMints )
+            continue;
+        assert( Lmax < Lmin );
+        return Lmin;
+    }
+    return 0;
+}
+int Extra_ThreshSelectWeights( word * t, int nVars, int * pW )
+{
+    if ( nVars <= 2 )
+        return (t[0] & 0xF) != 6 && (t[0] & 0xF) != 9;
+    if ( nVars == 3 )
+        return Extra_ThreshSelectWeights3( t, nVars, pW );
+    if ( nVars == 4 )
+        return Extra_ThreshSelectWeights4( t, nVars, pW );
+    if ( nVars == 5 )
+        return Extra_ThreshSelectWeights5( t, nVars, pW );
+    if ( nVars == 6 )
+        return Extra_ThreshSelectWeights6( t, nVars, pW );
+    if ( nVars == 7 )
+        return Extra_ThreshSelectWeights7( t, nVars, pW );
+    if ( nVars == 8 )
+        return Extra_ThreshSelectWeights8( t, nVars, pW );
+    return 0;
+}
+int Extra_ThreshCheck( word * t, int nVars, int * pW )
+{
+    int Chow[16], Chow0, nMints = (1 << nVars);
+    if ( !Abc_TtIsUnate(t, nVars) )
+        return 0;
+    Abc_TtMakePosUnate( t, nVars );
+    Chow0 = Extra_ThreshComputeChow( t, nVars, Chow );
+    Extra_ThreshSortByChow( t, nVars, Chow );
+    return Extra_ThreshSelectWeights( t, nVars, pW );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks unateness of a function.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Extra_ThreshCheckTest()
+{
+    int nVars = 5;
+    int T, Chow0, Chow[16], Weights[16];
+//    word t =  s_Truths6[0] & s_Truths6[1] & s_Truths6[2] & s_Truths6[3] & s_Truths6[4];
+//    word t =  (s_Truths6[0] & s_Truths6[1]) | (s_Truths6[0] & s_Truths6[2] & s_Truths6[3]) | (s_Truths6[0] & s_Truths6[2] & s_Truths6[4]);
+    word t =  (s_Truths6[2] & s_Truths6[1]) | (s_Truths6[2] & s_Truths6[0] & s_Truths6[3]) | (s_Truths6[2] & s_Truths6[0] & ~s_Truths6[4]);
+//    word t =  (s_Truths6[0] & s_Truths6[1]) | (s_Truths6[0] & s_Truths6[2] & s_Truths6[3]) | (s_Truths6[0] & s_Truths6[2] & s_Truths6[4]) | (s_Truths6[1] & s_Truths6[2] & s_Truths6[3]);
+//    word t =  (s_Truths6[0] & s_Truths6[1]) | (s_Truths6[0] & s_Truths6[2]) | (s_Truths6[0] & s_Truths6[3] & s_Truths6[4] & s_Truths6[5]) | 
+//        (s_Truths6[1] & s_Truths6[2] & s_Truths6[3]) | (s_Truths6[1] & s_Truths6[2] & s_Truths6[4]) | (s_Truths6[1] & s_Truths6[2] & s_Truths6[5]);
+    int i;
+    assert( nVars <= 8 );
+    for ( i = 0; i < nVars; i++ )
+        printf( "%d %d %d\n", i, Abc_TtPosVar(&t, nVars, i), Abc_TtNegVar(&t, nVars, i) );
+//    word t = s_Truths6[0] & s_Truths6[1] & s_Truths6[2];
+    Chow0 = Extra_ThreshComputeChow( &t, nVars, Chow );
+    if ( (T = Extra_ThreshCheck(&t, nVars, Weights)) )
+        Extra_ThreshPrintChow( T, Weights, nVars );
+    else
+        printf( "No threshold\n" );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/misc/extra/module.make b/src/misc/extra/module.make
index 1503cec1..87ba8559 100644
--- a/src/misc/extra/module.make
+++ b/src/misc/extra/module.make
@@ -18,5 +18,6 @@ SRC +=    src/misc/extra/extraBddAuto.c \
     src/misc/extra/extraUtilProgress.c \
     src/misc/extra/extraUtilReader.c \
     src/misc/extra/extraUtilSupp.c \
+    src/misc/extra/extraUtilTrash.c \
     src/misc/extra/extraUtilTruth.c \
     src/misc/extra/extraUtilUtil.c
diff --git a/src/misc/util/utilIsop.c b/src/misc/util/utilIsop.c
index f42dcabe..a62fc84d 100644
--- a/src/misc/util/utilIsop.c
+++ b/src/misc/util/utilIsop.c
@@ -95,47 +95,6 @@ static inline void Abc_IsopAddLits( int * pCover, int nCost0, int nCost1, int Va
     for ( c = 0; c < nCost1; c++ )
         pCover[nCost0+c] |= (1 << Abc_Var2Lit(Var,1));
 }
-int Abc_Isop6Cover2( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim, int * pCover )
-{
-    word uOn0, uOn1, uOnDc0, uOnDc1, uRes0, uRes1, uRes2;
-    int Var, nCost0, nCost1, nCost2;
-    assert( nVars <= 6 );
-    assert( (uOn & ~uOnDc) == 0 );
-    if ( uOn == 0 )
-    {
-        pRes[0] = 0;
-        return 0;
-    }
-    if ( uOnDc == ~(word)0 )
-    {
-        pRes[0] = ~(word)0;
-        if ( pCover ) pCover[0] = 0;
-        return (1 << 16);
-    }
-    assert( nVars > 0 );
-    // find the topmost var
-    for ( Var = nVars-1; Var >= 0; Var-- )
-        if ( Abc_Tt6HasVar( uOn, Var ) || Abc_Tt6HasVar( uOnDc, Var ) )
-             break;
-    assert( Var >= 0 );
-    // cofactor
-    uOn0   = Abc_Tt6Cofactor0( uOn,   Var );
-    uOn1   = Abc_Tt6Cofactor1( uOn  , Var );
-    uOnDc0 = Abc_Tt6Cofactor0( uOnDc, Var );
-    uOnDc1 = Abc_Tt6Cofactor1( uOnDc, Var );
-    // solve for cofactors
-    nCost0 = Abc_Isop6Cover2( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
-    if ( nCost0 >= nCostLim ) return nCostLim;
-    nCost1 = Abc_Isop6Cover2( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
-    if ( nCost0 + nCost1 >= nCostLim ) return nCostLim;
-    nCost2 = Abc_Isop6Cover2( (uOn0 & ~uRes0) | (uOn1 & ~uRes1), uOnDc0 & uOnDc1, &uRes2, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) + (nCost1 >> 16) : NULL );
-    if ( nCost0 + nCost1 + nCost2 >= nCostLim ) return nCostLim;
-    // derive the final truth table
-    *pRes = uRes2 | (uRes0 & s_Truths6Neg[Var]) | (uRes1 & s_Truths6[Var]);
-    assert( (uOn & ~*pRes) == 0 && (*pRes & ~uOnDc) == 0 );
-    Abc_IsopAddLits( pCover, nCost0, nCost1, Var );
-    return nCost0 + nCost1 + nCost2 + (nCost0 >> 16) + (nCost1 >> 16);
-}
 int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim, int * pCover )
 {
     word uOn0, uOn1, uOnDc0, uOnDc1, uRes0, uRes1, uRes2;
@@ -164,13 +123,10 @@ int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim,
     uOn1   = Abc_Tt6Cofactor1( uOn  , Var );
     uOnDc0 = Abc_Tt6Cofactor0( uOnDc, Var );
     uOnDc1 = Abc_Tt6Cofactor1( uOnDc, Var );
-//R0 = bsop(L0&~(U1 | (L1 &  ~U0)),U0,new_varbs)
     // solve for cofactors
-//    nCost0 = Abc_Isop6Cover( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
-    nCost0 = Abc_Isop6Cover( uOn0 & ~(uOnDc1 | (uOn1 & ~uOnDc0)), uOnDc0, &uRes0, Var, nCostLim, pCover );
+    nCost0 = Abc_Isop6Cover( uOn0 & ~uOnDc1, uOnDc0, &uRes0, Var, nCostLim, pCover );
     if ( nCost0 >= nCostLim ) return nCostLim;
-//    nCost1 = Abc_Isop6Cover( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
-    nCost1 = Abc_Isop6Cover( uOn1 & ~(uOnDc0 | (uOn0 & ~uOnDc1)), uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
+    nCost1 = Abc_Isop6Cover( uOn1 & ~uOnDc0, uOnDc1, &uRes1, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) : NULL );
     if ( nCost0 + nCost1 >= nCostLim ) return nCostLim;
     nCost2 = Abc_Isop6Cover( (uOn0 & ~uRes0) | (uOn1 & ~uRes1), uOnDc0 & uOnDc1, &uRes2, Var, nCostLim, pCover ? pCover + (nCost0 >> 16) + (nCost1 >> 16) : NULL );
     if ( nCost0 + nCost1 + nCost2 >= nCostLim ) return nCostLim;
@@ -180,7 +136,6 @@ int Abc_Isop6Cover( word uOn, word uOnDc, word * pRes, int nVars, int nCostLim,
     Abc_IsopAddLits( pCover, nCost0, nCost1, Var );
     return nCost0 + nCost1 + nCost2 + (nCost0 >> 16) + (nCost1 >> 16);
 }
-
 int Abc_Isop7Cover( word * pOn, word * pOnDc, word * pRes, int * pCover, int nCostLim )
 {
     word uOn0, uOn1, uOn2, uOnDc2, uRes0, uRes1, uRes2;
@@ -622,13 +577,11 @@ int Abc_Isop( word * pFunc, int nVars, int Type, int nCubeLim, Vec_Int_t * vCove
 ***********************************************************************/
 int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
 {
-    int fVerbose = 1;
+    int Cost, fVerbose = 0;
     word pRes[1024];
-    int Cost;
 //    if ( fVerbose )
 //    Dau_DsdPrintFromTruth( pFunc, nVars ), printf( "         " );
 
-
     Cost = Abc_IsopCheck( pFunc, pFunc, pRes, nVars, ABC_INFINITY, Vec_IntArray(vCover) );
     vCover->nSize = Cost >> 16;
     assert( vCover->nSize <= vCover->nCap );
@@ -646,7 +599,7 @@ int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
     printf( "%5d(%5d) ", Cost >> 16, Cost & 0xFFFF );
     Abc_IsopVerify( pFunc, nVars, pRes, vCover, 0, 1 );
 
-/*
+
     Cost = Abc_EsopCheck( pFunc, nVars, ABC_INFINITY, Vec_IntArray(vCover) );
     vCover->nSize = Cost >> 16;
     assert( vCover->nSize <= vCover->nCap );
@@ -663,12 +616,11 @@ int Abc_IsopTest( word * pFunc, int nVars, Vec_Int_t * vCover )
     if ( fVerbose )
     printf( "%5d(%5d)  ", Cost >> 16, Cost & 0xFFFF );
     Abc_IsopVerify( pFunc, nVars, pRes, vCover, 1, 1 );
-*/
+
 
     if ( fVerbose )
     printf( "\n" );
 //Kit_TruthIsopPrintCover( vCover, nVars, 0 );
-
     return 1; 
 }
 
diff --git a/src/misc/util/utilTruth.h b/src/misc/util/utilTruth.h
index 1416034d..0b52b3f4 100644
--- a/src/misc/util/utilTruth.h
+++ b/src/misc/util/utilTruth.h
@@ -1597,6 +1597,101 @@ static inline void Abc_TtReverseBits( word * pTruth, int nVars )
 
 /**Function*************************************************************
 
+  Synopsis    [Checks unateness of a function.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Abc_Tt6PosVar( word t, int iVar )
+{
+    return ((t >> (1<<iVar)) & t & s_Truths6Neg[iVar]) == (t & s_Truths6Neg[iVar]);
+}
+static inline int Abc_Tt6NegVar( word t, int iVar )
+{
+    return ((t << (1<<iVar)) & t & s_Truths6[iVar]) == (t & s_Truths6[iVar]);
+}
+static inline int Abc_TtPosVar( word * t, int nVars, int iVar )
+{
+    assert( iVar < nVars );
+    if ( nVars <= 6 )
+        return Abc_Tt6PosVar( t[0], iVar );
+    if ( iVar < 6 )
+    {
+        int i, Shift = (1 << iVar);
+        int nWords = Abc_TtWordNum( nVars );
+        for ( i = 0; i < nWords; i++ )
+            if ( ((t[i] >> Shift) & t[i] & s_Truths6Neg[iVar]) != (t[i] & s_Truths6Neg[iVar]) )
+                return 0;
+        return 1;
+    }
+    else
+    {
+        int i, Step = (1 << (iVar - 6));
+        word * tLimit = t + Abc_TtWordNum( nVars );
+        for ( ; t < tLimit; t += 2*Step )
+            for ( i = 0; i < Step; i++ )
+                if ( t[i] != (t[i] & t[Step+i]) )
+                    return 0;
+        return 1;
+    }
+}
+static inline int Abc_TtNegVar( word * t, int nVars, int iVar )
+{
+    assert( iVar < nVars );
+    if ( nVars <= 6 )
+        return Abc_Tt6NegVar( t[0], iVar );
+    if ( iVar < 6 )
+    {
+        int i, Shift = (1 << iVar);
+        int nWords = Abc_TtWordNum( nVars );
+        for ( i = 0; i < nWords; i++ )
+            if ( ((t[i] << Shift) & t[i] & s_Truths6[iVar]) != (t[i] & s_Truths6[iVar]) )
+                return 0;
+        return 1;
+    }
+    else
+    {
+        int i, Step = (1 << (iVar - 6));
+        word * tLimit = t + Abc_TtWordNum( nVars );
+        for ( ; t < tLimit; t += 2*Step )
+            for ( i = 0; i < Step; i++ )
+                if ( (t[i] & t[Step+i]) != t[Step+i] )
+                    return 0;
+        return 1;
+    }
+}
+static inline int Abc_TtIsUnate( word * t, int nVars )
+{
+    int i;
+    for ( i = 0; i < nVars; i++ )
+        if ( !Abc_TtNegVar(t, nVars, i) && !Abc_TtPosVar(t, nVars, i) )
+            return 0;
+    return 1;
+}
+static inline int Abc_TtIsPosUnate( word * t, int nVars )
+{
+    int i;
+    for ( i = 0; i < nVars; i++ )
+        if ( !Abc_TtPosVar(t, nVars, i) )
+            return 0;
+    return 1;
+}
+static inline void Abc_TtMakePosUnate( word * t, int nVars )
+{
+    int i, nWords = Abc_TtWordNum(nVars);
+    for ( i = 0; i < nVars; i++ )
+        if ( Abc_TtNegVar(t, nVars, i) )
+            Abc_TtFlip( t, nWords, i );
+        else assert( Abc_TtPosVar(t, nVars, i) );
+}
+
+
+/**Function*************************************************************
+
   Synopsis    [Computes ISOP for 6 variables or less.]
 
   Description []