Version abc51001

5 files changed, 995 insertions, 0 deletions

diff --git a/src/misc/npn/npn.c b/src/misc/npn/npn.c
new file mode 100644
index 00000000..ad4b4de6
--- /dev/null
+++ b/src/misc/npn/npn.c
@@ -0,0 +1,202 @@
+/**CFile****************************************************************
+
+  FileName    [npn.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName []
+
+  Synopsis    []
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: npn.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "extra.h"
+#include "npn.h"
+#include "vec.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+static int Npn_CompareVecs( void ** p0, void ** p1 );
+static Vec_Int_t * Npn_GetSignature( unsigned uTruth, int nVars );
+static void Npn_VecPrint( FILE * pFile, Vec_Int_t * vVec );
+static int Npn_VecProperty( Vec_Int_t * vVec );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_Experiment()
+{
+    Vec_Int_t ** pVecs;
+    FILE * pFile;
+    int nFuncs, Num, i;
+
+    pFile = fopen( "npn5.txt", "r" );
+    pVecs = ALLOC( Vec_Int_t *, 1000000 );
+    for ( i = 0; ; i++ )
+    {
+        if ( fscanf( pFile, "%x", &Num ) != 1 )
+            break;
+        pVecs[i] = Npn_GetSignature( Num, 5 );
+        if ( Npn_VecProperty( pVecs[i] ) )
+        {
+            printf( "1s = %2d. ", Extra_CountOnes((unsigned char *)&Num, (1 << 5) / 8) );
+            Extra_PrintHex( stdout, Num, 5 ); fprintf( stdout, "\n" );
+        }
+        
+    }
+    nFuncs = i;
+    printf( "Read %d numbers.\n", nFuncs );
+    fclose( pFile );
+    /*
+    // sort the vectors
+    qsort( (void *)pVecs, nFuncs, sizeof(void *), 
+            (int (*)(const void *, const void *)) Npn_CompareVecs );
+    pFile = fopen( "npn5ar.txt", "w" );
+    for ( i = 0; i < nFuncs; i++ )
+    {
+        Npn_VecPrint( pFile, pVecs[i] );
+        Vec_IntFree( pVecs[i] );
+    }
+    fclose( pFile );
+    */
+
+    free( pVecs );
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Npn_GetSignature( unsigned uTruth, int nVars )
+{
+    // elementary truth tables
+    static unsigned Signs[5] = {
+        0xAAAAAAAA,    // 1010 1010 1010 1010 1010 1010 1010 1010
+        0xCCCCCCCC,    // 1010 1010 1010 1010 1010 1010 1010 1010
+        0xF0F0F0F0,    // 1111 0000 1111 0000 1111 0000 1111 0000
+        0xFF00FF00,    // 1111 1111 0000 0000 1111 1111 0000 0000
+        0xFFFF0000     // 1111 1111 1111 1111 0000 0000 0000 0000
+    };
+    Vec_Int_t * vVec;
+    unsigned uCofactor;
+    int Count0, Count1, i;
+    int nBytes = (1 << nVars) / 8;
+
+    // collect the number of 1s in each cofactor
+    vVec = Vec_IntAlloc( 5 );
+    for ( i = 0; i < nVars; i++ )
+    {
+        uCofactor = uTruth & ~Signs[i];
+        Count0 = Extra_CountOnes( (unsigned char *)&uCofactor, nBytes );
+        uCofactor = uTruth &  Signs[i];
+        Count1 = Extra_CountOnes( (unsigned char *)&uCofactor, nBytes );
+        if ( Count0 < Count1 )
+            Vec_IntPush( vVec, Count0 );
+        else
+            Vec_IntPush( vVec, Count1 );
+    }
+    // sort them
+    Vec_IntSort( vVec, 0 );
+    return vVec;
+    
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_CompareVecs( void ** p0, void ** p1 )
+{
+    Vec_Int_t * vVec0 = *p0;
+    Vec_Int_t * vVec1 = *p1;
+    int i;
+    assert( vVec0->nSize == vVec1->nSize );
+    for ( i = 0; i < vVec0->nSize; i++ )
+        if ( vVec0->pArray[i] < vVec1->pArray[i] )
+            return -1;
+        else if ( vVec0->pArray[i] > vVec1->pArray[i] )
+            return 1;
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_VecPrint( FILE * pFile, Vec_Int_t * vVec )
+{
+    int i;
+    for ( i = 0; i < vVec->nSize; i++ )
+        fprintf( pFile, "%2d ", vVec->pArray[i] );
+    fprintf( pFile, "\n" );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_VecProperty( Vec_Int_t * vVec )
+{
+    int i;
+    for ( i = 0; i < vVec->nSize; i++ )
+        if ( vVec->pArray[i] != i + 1 )
+            return 0;
+    return 1;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/misc/npn/npn.h b/src/misc/npn/npn.h
new file mode 100644
index 00000000..61aa6297
--- /dev/null
+++ b/src/misc/npn/npn.h
@@ -0,0 +1,105 @@
+/**CFile****************************************************************
+
+  FileName    [npn.h]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName []
+
+  Synopsis    [External declarations.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: npn.h,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+ 
+#ifndef __NPN_H__
+#define __NPN_H__
+
+////////////////////////////////////////////////////////////////////////
+///                          INCLUDES                                ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                         PARAMETERS                               ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                         BASIC TYPES                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                      MACRO DEFITIONS                             ///
+////////////////////////////////////////////////////////////////////////
+
+#define EXTRA_WORD_VARS     5
+
+////////////////////////////////////////////////////////////////////////
+///                    FUNCTION DEFINITIONS                          ///
+////////////////////////////////////////////////////////////////////////
+
+static inline int Extra_BitCharNum( int nVars )  {  if ( nVars <= 3 )  return 1;                return 1 << (nVars - 3); }
+static inline int Extra_BitWordNum( int nVars )  {  if ( nVars <= EXTRA_WORD_VARS )  return 1;  return 1 << (nVars - EXTRA_WORD_VARS); }
+
+static inline int  Extra_BitRead( uint8 * pBits, int iBit )  { return ( (pBits[iBit/8] & (1 << (iBit%8))) > 0 ); }
+static inline void Extra_BitSet( uint8 * pBits, int iBit )   { pBits[iBit/8] |= (1 << (iBit%8));                 }
+static inline void Extra_BitXor( uint8 * pBits, int iBit )   { pBits[iBit/8] ^= (1 << (iBit%8));                 }
+
+static inline void Extra_BitClean( int nVars, uint8 * pBits )
+{
+    unsigned * pWords = (unsigned *)pBits;
+    int i;
+    for ( i = Extra_BitWordNum(nVars) - 1; i >= 0; i-- )
+        pWords[i] = 0;
+}
+static inline void Extra_BitNot( int nVars, uint8 * pBits )
+{
+    unsigned * pWords = (unsigned *)pBits;
+    int i;
+    for ( i = Extra_BitWordNum(nVars) - 1; i >= 0; i-- )
+        pWords[i] = ~pWords[i];
+}
+static inline void Extra_BitCopy( int nVars, uint8 * pBits1, uint8 * pBits )
+{
+    unsigned * pWords  = (unsigned *)pBits;
+    unsigned * pWords1 = (unsigned *)pBits1;
+    int i;
+    for ( i = Extra_BitWordNum(nVars) - 1; i >= 0; i-- )
+        pWords[i] = pWords1[i];
+}
+static inline void Extra_BitAnd( int nVars, uint8 * pBits1, uint8 * pBits2, uint8 * pBits )
+{
+    unsigned * pWords  = (unsigned *)pBits;
+    unsigned * pWords1 = (unsigned *)pBits1;
+    unsigned * pWords2 = (unsigned *)pBits2;
+    int i;
+    for ( i = Extra_BitWordNum(nVars) - 1; i >= 0; i-- )
+        pWords[i] = pWords1[i] & pWords2[i];
+}
+static inline void Extra_BitSharp( int nVars, uint8 * pBits1, uint8 * pBits2, uint8 * pBits )
+{
+    unsigned * pWords  = (unsigned *)pBits;
+    unsigned * pWords1 = (unsigned *)pBits1;
+    unsigned * pWords2 = (unsigned *)pBits2;
+    int i;
+    for ( i = Extra_BitWordNum(nVars) - 1; i >= 0; i-- )
+        pWords[i] = pWords1[i] & ~pWords2[i];
+}
+
+////////////////////////////////////////////////////////////////////////
+///                    FUNCTION DECLARATIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/*=== zzz.c ==========================================================*/
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+#endif
+
diff --git a/src/misc/npn/npnGenStr.c b/src/misc/npn/npnGenStr.c
new file mode 100644
index 00000000..adbfdcdf
--- /dev/null
+++ b/src/misc/npn/npnGenStr.c
@@ -0,0 +1,473 @@
+/**CFile****************************************************************
+
+  FileName    [npnUtil.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName []
+
+  Synopsis    []
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: npnUtil.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "extra.h"
+#include "npn.h"
+#include "vec.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+static Vec_Ptr_t * Npn_Generate_rec( int nVars, int fFold );
+static void Npn_GenerateMerge( Vec_Ptr_t * vVec1, Vec_Ptr_t * vVec2, Vec_Ptr_t * vVec );
+static void Npn_GenerateFree( Vec_Ptr_t * vVec );
+static Vec_Ptr_t * Npn_GenerateFold( Vec_Ptr_t * vVec );
+static void Npn_GenerateEmbed( Vec_Ptr_t * vVec );
+static void Npn_GeneratePrint( Vec_Ptr_t * vVec );
+
+
+static void Npn_RewritePrint( Vec_Ptr_t * vVec );
+static Vec_Ptr_t * Npn_Rewrite( char * pStruct );
+
+static int Npn_RewriteNumEntries( char * pString );
+static int Npn_RewriteLastAnd( char * pBeg, char * pString );
+static int Npn_RewriteLastExor( char * pBeg, char * pString );
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_Generate()
+{
+    Vec_Ptr_t * vVec;
+    vVec = Npn_Generate_rec( 7, 1 );
+    Npn_GenerateEmbed( vVec );
+    Npn_GeneratePrint( vVec );
+    Npn_GenerateFree( vVec );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Ptr_t * Npn_Generate_rec( int nVars, int fFold )
+{
+    char Buffer[20], * pChar;
+    Vec_Ptr_t * vVec, * vVec1, * vVec2, * pTemp;
+    int i;
+
+    vVec = Vec_PtrAlloc( 100 );
+
+    // generate the combination
+    pChar = Buffer;
+    for ( i = 0; i < nVars; i++ )
+        *pChar++ = '.';
+    *pChar++ = 0;
+
+    Vec_PtrPush( vVec, util_strsav(Buffer) );
+    if ( nVars == 2 || !fFold )
+        return vVec;
+
+    assert( nVars > 2 );
+    for ( i = 2; i < nVars; i++ )
+    {
+        vVec1 = Npn_Generate_rec( i, 1 );
+        vVec1 = Npn_GenerateFold( pTemp = vVec1 );
+        Npn_GenerateFree( pTemp );
+        // add folded pairs
+        if ( nVars - i > 1 )
+        {
+            vVec2 = Npn_Generate_rec( nVars - i, 1 );
+            vVec2 = Npn_GenerateFold( pTemp = vVec2 );
+            Npn_GenerateFree( pTemp );
+            Npn_GenerateMerge( vVec1, vVec2, vVec );
+            Npn_GenerateFree( vVec2 );
+        }
+        // add unfolded pairs
+        vVec2 = Npn_Generate_rec( nVars - i, 0 );
+        Npn_GenerateMerge( vVec1, vVec2, vVec );
+        Npn_GenerateFree( vVec2 );
+        Npn_GenerateFree( vVec1 );
+    }
+    return vVec;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_GenerateMerge( Vec_Ptr_t * vVec1, Vec_Ptr_t * vVec2, Vec_Ptr_t * vVec )
+{
+    char Buffer[100];
+    char * pEntry1, * pEntry2, * pEntry;
+    int i, k, m;
+    Vec_PtrForEachEntry( vVec1, pEntry1, i )
+    Vec_PtrForEachEntry( vVec2, pEntry2, k )
+    {
+        if ( *pEntry1 == '(' && *pEntry2 == '(' )
+            if ( strcmp( pEntry1, pEntry2 ) > 0 )
+                continue;
+
+        // get the new entry
+        sprintf( Buffer, "%s%s", pEntry1, pEntry2 );
+        // skip duplicates
+        Vec_PtrForEachEntry( vVec, pEntry, m )
+            if ( strcmp( pEntry, Buffer ) == 0 )
+                break;
+        if ( m != Vec_PtrSize(vVec) )
+            continue;
+        // add the new entry
+        Vec_PtrPush( vVec, util_strsav(Buffer) );
+    }    
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_GenerateFree( Vec_Ptr_t * vVec )
+{
+    char * pEntry;
+    int i;
+    Vec_PtrForEachEntry( vVec, pEntry, i )
+        free( pEntry );
+    Vec_PtrFree( vVec );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Ptr_t * Npn_GenerateFold( Vec_Ptr_t * vVec )
+{
+    Vec_Ptr_t * vVecR;
+    char Buffer[100];
+    char * pEntry;
+    int i;
+    vVecR = Vec_PtrAlloc( 10 );
+    Vec_PtrForEachEntry( vVec, pEntry, i )
+    {
+        // add entry without folding if the second part is folded
+        if ( pEntry[strlen(pEntry) - 1] == ')' )
+            Vec_PtrPush( vVecR, util_strsav(pEntry) );
+        // add the entry with folding
+        sprintf( Buffer, "(%s)", pEntry );
+        Vec_PtrPush( vVecR, util_strsav(Buffer) );
+    }
+    return vVecR;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_GenerateEmbed( Vec_Ptr_t * vVec )
+{
+    char Buffer[100];
+    char * pEntry;
+    int i;
+    Vec_PtrForEachEntry( vVec, pEntry, i )
+    {
+        sprintf( Buffer, "(%s)", pEntry );
+        Vec_PtrWriteEntry( vVec, i, util_strsav(Buffer) );
+        free( pEntry );
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_GeneratePrint( Vec_Ptr_t * vVec )
+{
+    char * pEntry;
+    int i;
+    Vec_PtrForEachEntry( vVec, pEntry, i )
+    {
+        printf( "%5d : %s\n", i, pEntry );
+
+        {
+            Vec_Ptr_t * vFuncs;
+            vFuncs = Npn_Rewrite( pEntry );
+            Npn_RewritePrint( vFuncs );
+            Vec_PtrFree( vFuncs );
+        }
+    }
+}
+
+
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_RewritePrint( Vec_Ptr_t * vVec )
+{
+    char * pEntry;
+    int i;
+    Vec_PtrForEachEntry( vVec, pEntry, i )
+        printf( "    %3d : %s\n", i, pEntry );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_Rewrite_rec( char * pStruct, Vec_Ptr_t * vVec, Vec_Str_t * vForm )
+{
+    int nSizeOld;
+    char * pCur;
+    // find the next opening paranthesis
+    for ( pCur = pStruct; *pCur; pCur++ )
+    {
+        if ( *pCur == '(' )
+            break;
+        Vec_StrPush( vForm, *pCur );
+    }
+    // the paranthesis is not found quit
+    if ( *pCur == 0 )
+    {
+        Vec_StrPush( vForm, 0 );
+        Vec_PtrPush( vVec, util_strsav( vForm->pArray ) );
+        return;
+    }
+    assert( *pCur == '(' );
+    pCur++;
+    // remember the current size
+    nSizeOld = vForm->nSize;
+    // add different types
+    if ( Npn_RewriteLastAnd(vForm->pArray, vForm->pArray+vForm->nSize) )
+    {
+        Vec_StrPush( vForm, 'N' );
+        Vec_StrPush( vForm, '(' );
+        Npn_Rewrite_rec( pCur, vVec, vForm );
+        Vec_StrShrink( vForm, nSizeOld );
+    }
+    else
+    {
+        Vec_StrPush( vForm, 'A' );
+        Vec_StrPush( vForm, '(' );
+        Npn_Rewrite_rec( pCur, vVec, vForm );
+        Vec_StrShrink( vForm, nSizeOld );
+    }
+    // add different types
+    if ( Npn_RewriteNumEntries(pCur) == 3 )
+    {
+        Vec_StrPush( vForm, 'P' );
+        Vec_StrPush( vForm, '(' );
+        Npn_Rewrite_rec( pCur, vVec, vForm );
+        Vec_StrShrink( vForm, nSizeOld );
+    }
+    // add different types
+    if ( !Npn_RewriteLastExor(vForm->pArray, vForm->pArray+vForm->nSize) )
+    {
+        Vec_StrPush( vForm, 'X' );
+        Vec_StrPush( vForm, '(' );
+        Npn_Rewrite_rec( pCur, vVec, vForm );
+        Vec_StrShrink( vForm, nSizeOld );
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Ptr_t * Npn_Rewrite( char * pStruct )
+{
+    Vec_Ptr_t * vVec;
+    Vec_Str_t * vForm;
+    vVec  = Vec_PtrAlloc( 10 );
+    vForm = Vec_StrAlloc( 10 );
+    Npn_Rewrite_rec( pStruct, vVec, vForm );
+    Vec_StrFree( vForm );
+    return vVec;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_RewriteNumEntries( char * pString )
+{
+    char * pCur;
+    int Counter = 0;
+    int nPars = 0;
+    for ( pCur = pString; *pCur; pCur++ )
+    {
+        if ( nPars == 0 )
+        {
+            if ( *pCur == '.' )
+                Counter++;
+            else if ( *pCur == '(' )
+            {
+                Counter++;
+                nPars++;
+            }
+            else if ( *pCur == ')' )
+                nPars--;
+        }
+        else if ( nPars > 0 )
+        {
+            if ( *pCur == '(' )
+                nPars++;
+            else if ( *pCur == ')' )
+                nPars--;
+        }
+        else
+            break;
+    }
+    return Counter;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 1 if the last was EXOR.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_RewriteLastAnd( char * pBeg, char * pEnd )
+{
+    char * pCur;
+    int nPars = 1;
+    for ( pCur = pEnd - 1; pCur >= pBeg; pCur-- )
+    {
+            if ( *pCur == ')' )
+                nPars++;
+            else if ( *pCur == '(' )
+                nPars--;
+
+            if ( nPars == 0 && *pCur == 'A' )
+                return 1;
+    }
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Returns 1 if the last was EXOR.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_RewriteLastExor( char * pBeg, char * pEnd )
+{
+    char * pCur;
+    int nPars = 1;
+    for ( pCur = pEnd - 1; pCur >= pBeg; pCur-- )
+    {
+            if ( *pCur == ')' )
+                nPars++;
+            else if ( *pCur == '(' )
+                nPars--;
+
+            if ( nPars == 0 && *pCur == 'X' )
+                return 1;
+    }
+    return 0;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/misc/npn/npnTruth.c b/src/misc/npn/npnTruth.c
new file mode 100644
index 00000000..b6be775b
--- /dev/null
+++ b/src/misc/npn/npnTruth.c
@@ -0,0 +1,137 @@
+/**CFile****************************************************************
+
+  FileName    [npnUtil.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName []
+
+  Synopsis    []
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: npnUtil.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "extra.h"
+#include "npn.h"
+#include "vec.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Checks if the variable belongs to the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Extra_TruthCofactors( int nVars, uint8 * puTruth, uint8 * puElem[][32], 
+    uint8 * puTruthCofs0[][32], uint8 * puTruthCofs1[][32] )
+{
+    int v;
+    for ( v = 0; v < nVars; v++ )
+    {
+        Extra_BitSharp( nVars, puTruth, puElem[v], (uint8 *)puTruthCofs0[v] );
+        Extra_BitAnd  ( nVars, puTruth, puElem[v], (uint8 *)puTruthCofs1[v] );
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks if the variable belongs to the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Extra_TruthCountCofactorOnes( int nVars, uint8 * puTruthCofs[][32], int * pCounts )
+{
+    int v, nBytes;
+    nBytes = Extra_BitCharNum( nVars );
+    for ( v = 0; v < nVars; v++ )
+        pCounts[v] = Extra_CountOnes( puTruthCofs[v], nBytes );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks if the variable belongs to the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Extra_TruthHasVar( int nVars, uint8 * puTruth, int iVar )
+{
+    // elementary truth tables
+    static uint8 Signs[3] = {
+        0xAA,    // 1010 1010
+        0xCC,    // 1100 1100
+        0xF0     // 1111 0000
+    };
+    int nChars, nShift, i;
+    assert( iVar < nVars );
+    nChars = Extra_BitCharNum( nVars );
+    if ( iVar < 3 )
+    {
+        nShift = (1 << iVar);
+        for ( i = 0; i < nChars; i++ )
+            if ( ((puTruth[i] & Signs[iVar]) >> nShift) != (puTruth[i] & ~Signs[iVar]) )
+                return 1;
+    }
+    else
+    {
+        nShift = (1 << (iVar-3));
+        for ( i = 0; i < nChars; i++, i = (i % nShift)? i : i + nShift )
+            if ( puTruth[i] != puTruth[i+nShift] )
+                return 1;
+    }
+    return 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Checks if the variable belongs to the support.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Npn_VarsTest( int nVars, uint8 * puTruth )
+{
+    int v;
+    int Counter = 0;
+    for ( v = 0; v < nVars; v++ )
+        Counter += Extra_TruthHasVar( nVars, puTruth, v );
+    return Counter;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
diff --git a/src/misc/npn/npnUtil.c b/src/misc/npn/npnUtil.c
new file mode 100644
index 00000000..b12ad092
--- /dev/null
+++ b/src/misc/npn/npnUtil.c
@@ -0,0 +1,78 @@
+/**CFile****************************************************************
+
+  FileName    [npnUtil.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName []
+
+  Synopsis    []
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: npnUtil.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "extra.h"
+#include "npn.h"
+#include "vec.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFITIONS                           ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_StartTruth8( uint8 uTruths[][32] )
+{
+    // elementary truth tables
+    static uint8 Signs[3] = {
+        0xAA,    // 1010 1010
+        0xCC,    // 1100 1100
+        0xF0     // 1111 0000
+    };
+    int v, i, nShift;
+    for ( v = 0; v < 3; v++ )
+        for ( i = 0; i < 32; i++ )
+            uTruths[v][i] = Signs[v];
+    for ( v = 3; v < 8; v++ )
+    {
+        nShift = (1 << (v-3));
+        for ( i = 0; i < 32; i++, i = (i % nShift)? i : i + nShift )
+        {
+            uTruths[v][i]          = 0;
+            uTruths[v][i + nShift] = 0xFF;
+        }
+    }
+/*
+    for ( v = 0; v < 8; v++ )
+    {
+        Extra_PrintBinary( stdout, (unsigned int*)uTruths[v], 90 );
+        printf( "\n" );
+    }
+*/
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+