NPN class computation.

3 files changed, 752 insertions, 8 deletions

diff --git a/src/base/abci/abcCut.c b/src/base/abci/abcCut.c
index e80ddb92..f8b27c32 100644
--- a/src/base/abci/abcCut.c
+++ b/src/base/abci/abcCut.c
@@ -122,7 +122,8 @@ void Abc_NtkCutsAddFanunt( Abc_Ntk_t * pNtk )
 Cut_Man_t * Abc_NtkCuts( Abc_Ntk_t * pNtk, Cut_Params_t * pParams )
 {
     ProgressBar * pProgress;
-    Cut_Man_t *  p;
+    Cut_Man_t * p;
+    Cut_Cut_t * pList;
     Abc_Obj_t * pObj, * pNode;
     Vec_Ptr_t * vNodes;
     Vec_Int_t * vChoices;
@@ -172,7 +173,15 @@ Cut_Man_t * Abc_NtkCuts( Abc_Ntk_t * pNtk, Cut_Params_t * pParams )
 //            continue;
         Extra_ProgressBarUpdate( pProgress, i, NULL );
         // compute the cuts to the internal node
-        Abc_NodeGetCuts( p, pObj, pParams->fDag, pParams->fTree );  
+        pList = Abc_NodeGetCuts( p, pObj, pParams->fDag, pParams->fTree );
+        if ( pParams->fNpnSave && pList )
+        {
+            extern void Npn_ManSaveOne( unsigned * puTruth, int nVars );
+            Cut_Cut_t * pCut;
+            for ( pCut = pList; pCut; pCut = pCut->pNext )
+                if ( pCut->nLeaves >= 4 )
+                    Npn_ManSaveOne( Cut_CutReadTruth(pCut), pCut->nLeaves );
+        }
         // consider dropping the fanins cuts
         if ( pParams->fDrop )
         {
@@ -193,7 +202,7 @@ Cut_Man_t * Abc_NtkCuts( Abc_Ntk_t * pNtk, Cut_Params_t * pParams )
     Vec_IntFree( vChoices );
     Cut_ManPrintStats( p );
 ABC_PRT( "TOTAL", clock() - clk );
-    printf( "Area = %d.\n", Abc_NtkComputeArea( pNtk, p ) );
+//    printf( "Area = %d.\n", Abc_NtkComputeArea( pNtk, p ) );
 //Abc_NtkPrintCuts( p, pNtk, 0 );
 //    Cut_ManPrintStatsToFile( p, pNtk->pSpec, clock() - clk );
 
@@ -428,7 +437,6 @@ void * Abc_NodeGetCuts( void * p, Abc_Obj_t * pObj, int fDag, int fTree )
 //    assert( Abc_NtkIsStrash(pObj->pNtk) );
     assert( Abc_ObjFaninNum(pObj) == 2 );
 
-
     // check if the node is a DAG node
     fDagNode = (Abc_ObjFanoutNum(pObj) > 1 && !Abc_NodeIsMuxControlType(pObj));
     // increment the counter of DAG nodes
@@ -444,7 +452,6 @@ void * Abc_NodeGetCuts( void * p, Abc_Obj_t * pObj, int fDag, int fTree )
         TreeCode |= ((Abc_ObjFanoutNum(pFanin) > 1 && !Abc_NodeIsMuxControlType(pFanin)) << 1);
     }
 
-
     // changes due to the global/local cut computation
     {
         Cut_Params_t * pParams = Cut_ManReadParams((Cut_Man_t *)p);
@@ -568,9 +575,6 @@ void Abc_NtkPrintCuts_( void * p, Abc_Ntk_t * pNtk, int fSeq )
     Cut_CutPrintList( pList, fSeq );
 }
 
-
-
-
 /**Function*************************************************************
 
   Synopsis    [Assigns global attributes randomly.]
diff --git a/src/base/abci/abcNpnSave.c b/src/base/abci/abcNpnSave.c
new file mode 100644
index 00000000..381409de
--- /dev/null
+++ b/src/base/abci/abcNpnSave.c
@@ -0,0 +1,739 @@
+/**CFile****************************************************************
+
+  FileName    [abcNpnSave.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Network and node package.]
+
+  Synopsis    [Interface with the FPGA mapping package.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - November 21, 2006.]
+
+  Revision    [$Id: abcNpnSave.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "abc.h"
+#include "aig.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+ 
+typedef struct Npn_Obj_t_ Npn_Obj_t;
+typedef struct Npn_Man_t_ Npn_Man_t;
+
+struct Npn_Obj_t_
+{
+    word         uTruth;      // truth table
+    int          Count;       // occurances
+    int          iNext;       // next entry
+};
+struct Npn_Man_t_
+{
+    Npn_Obj_t *  pBuffer;     // all NPN entries
+    int *        pBins;       // hash table
+    int          nBins;       // hash table size
+    int          nBufferSize; // buffer size
+    int          nEntries;    // entry count
+};
+
+static inline Npn_Obj_t * Npn_ManObj( Npn_Man_t * p, int i )                 { assert( i < p->nBufferSize ); return i ? p->pBuffer + i : NULL;  }
+static inline int         Npn_ManObjNum( Npn_Man_t * p, Npn_Obj_t * pObj )   { assert( p->pBuffer < pObj );  return pObj - p->pBuffer;          }
+
+static word Truth[8] = {
+    0xAAAAAAAAAAAAAAAA,
+    0xCCCCCCCCCCCCCCCC,
+    0xF0F0F0F0F0F0F0F0,
+    0xFF00FF00FF00FF00,
+    0xFFFF0000FFFF0000,
+    0xFFFFFFFF00000000,
+    0x0000000000000000,
+    0xFFFFFFFFFFFFFFFF
+};
+
+static Npn_Man_t * pNpnMan = NULL;
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_TruthPermute_rec( char * pStr, int mid, int end )
+{
+    static int count = 0;
+    char * pTemp = Aig_UtilStrsav(pStr);
+    char e;
+    int i;
+    if ( mid == end ) 
+    {
+        printf( "%03d: %s\n", count++, pTemp );
+        return ;
+    }
+    for ( i = mid; i <= end; i++ )
+    {
+        e = pTemp[mid];
+        pTemp[mid] = pTemp[i];
+        pTemp[i] = e;
+
+        Npn_TruthPermute_rec( pTemp, mid + 1, end );
+
+        e = pTemp[mid];
+        pTemp[mid] = pTemp[i];
+        pTemp[i] = e;
+    }
+    ABC_FREE( pTemp );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_TruthHasVar( word t, int v )
+{
+    return ((t & Truth[v]) >> (1<<v)) != (t & ~Truth[v]);
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_TruthSupport( word t )
+{
+    int v, Supp = 0;
+    for ( v = 0; v < 6; v++ )
+        if ( Npn_TruthHasVar( t, v ) )
+            Supp |= (1 << v);
+    return Supp;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_TruthSuppSize( word t, int nVars )
+{
+    int v, nSupp = 0;
+    assert( nVars <= 6 );
+    for ( v = 0; v < nVars; v++ )
+        if ( Npn_TruthHasVar( t, v ) )
+            nSupp++;
+    return nSupp;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_TruthIsMinBase( word t )
+{
+    int Supp = Npn_TruthSupport(t);
+    return (Supp & (Supp+1)) == 0;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+word Npn_TruthPadWord( word uTruth, int nVars )
+{
+    if ( nVars == 6 )
+        return uTruth;
+    if ( nVars <= 5 )
+        uTruth = ((uTruth & 0x00000000FFFFFFFF) << 32) | (uTruth & 0x00000000FFFFFFFF);
+    if ( nVars <= 4 )
+        uTruth = ((uTruth & 0x0000FFFF0000FFFF) << 16) | (uTruth & 0x0000FFFF0000FFFF);
+    if ( nVars <= 3 )
+        uTruth = ((uTruth & 0x00FF00FF00FF00FF) <<  8) | (uTruth & 0x00FF00FF00FF00FF);
+    if ( nVars <= 2 )
+        uTruth = ((uTruth & 0x0F0F0F0F0F0F0F0F) <<  4) | (uTruth & 0x0F0F0F0F0F0F0F0F);
+    if ( nVars <= 1 )
+        uTruth = ((uTruth & 0x3333333333333333) <<  2) | (uTruth & 0x3333333333333333);
+    if ( nVars == 0 )
+        uTruth = ((uTruth & 0x5555555555555555) <<  1) | (uTruth & 0x5555555555555555);
+    return uTruth;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_TruthCountOnes( word t )
+{
+    t =    (t & 0x5555555555555555) + ((t>> 1) & 0x5555555555555555);
+    t =    (t & 0x3333333333333333) + ((t>> 2) & 0x3333333333333333);
+    t =    (t & 0x0F0F0F0F0F0F0F0F) + ((t>> 4) & 0x0F0F0F0F0F0F0F0F);
+    t =    (t & 0x00FF00FF00FF00FF) + ((t>> 8) & 0x00FF00FF00FF00FF);
+    t =    (t & 0x0000FFFF0000FFFF) + ((t>>16) & 0x0000FFFF0000FFFF);
+    return (t & 0x00000000FFFFFFFF) +  (t>>32);
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline word Npn_TruthChangePhase( word t, int v )
+{
+    return ((t & Truth[v]) >> (1<<v)) | ((t & ~Truth[v]) << (1<<v));
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline word Npn_TruthSwapAdjacentVars( word t, int v )
+{
+    static word PMasks[5][3] = {
+        { 0x9999999999999999, 0x2222222222222222, 0x4444444444444444 },
+        { 0xC3C3C3C3C3C3C3C3, 0x0C0C0C0C0C0C0C0C, 0x3030303030303030 },
+        { 0xF00FF00FF00FF00F, 0x00F000F000F000F0, 0x0F000F000F000F00 },
+        { 0xFF0000FFFF0000FF, 0x0000FF000000FF00, 0x00FF000000FF0000 },
+        { 0xFFFF00000000FFFF, 0x00000000FFFF0000, 0x0000FFFF00000000 }
+    };
+    assert( v < 6 );
+    return (t & PMasks[v][0]) | ((t & PMasks[v][1]) << (1 << v)) | ((t & PMasks[v][2]) >> (1 << v));
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline word Npn_TruthCanon( word t, int nVars, int * pPhase )
+{
+    int fUsePolarity    = 0;
+    int fUsePermutation = 0;
+    char Temp, pSigs[13], pCanonPerm[6];
+    int v, fChange, CanonPhase = 0;
+    assert( nVars < 7 );
+    pSigs[12] = Npn_TruthCountOnes( t );
+    if ( pSigs[12] > 32 )
+    {
+        t = ~t;
+        pSigs[12] = 64 - pSigs[12];
+        CanonPhase |= (1 << 6);
+    }
+    if ( fUsePolarity || fUsePermutation )
+    {
+        for ( v = 0; v < nVars; v++ )
+        {
+            pCanonPerm[v] = v;
+            pSigs[2*v+1] = Npn_TruthCountOnes( t & Truth[v] );
+            pSigs[2*v] = pSigs[12] - pSigs[2*v+1];
+        }
+    }
+    if ( fUsePolarity )
+    {
+        for ( v = 0; v < nVars; v++ )
+        {
+            if ( pSigs[2*v] >= pSigs[2*v+1] )
+                continue;
+            CanonPhase |= (1 << v);
+            Temp = pSigs[2*v];
+            pSigs[2*v] = pSigs[2*v+1];
+            pSigs[2*v+1] = Temp;
+            t = Npn_TruthChangePhase( t, v );
+        }
+    }
+    if ( fUsePermutation )
+    {
+        do {
+            fChange = 0;
+            for ( v = 0; v < nVars-1; v++ )
+            {
+                if ( fUsePolarity )
+                {
+                    if ( pSigs[2*v] >= pSigs[2*(v+1)] )
+                        continue;
+                }
+                else
+                {
+                    if ( ABC_MIN(pSigs[2*v],pSigs[2*v+1]) >= ABC_MIN(pSigs[2*(v+1)],pSigs[2*(v+1)+1]) )
+                        continue;
+                }
+                fChange = 1;
+
+                Temp = pCanonPerm[v];
+                pCanonPerm[v] = pCanonPerm[v+1];
+                pCanonPerm[v+1] = Temp;
+
+                Temp = pSigs[2*v];
+                pSigs[2*v] = pSigs[2*(v+1)];
+                pSigs[2*(v+1)] = Temp;
+
+                Temp = pSigs[2*v+1];
+                pSigs[2*v+1] = pSigs[2*(v+1)+1];
+                pSigs[2*(v+1)+1] = Temp;
+
+                t = Npn_TruthSwapAdjacentVars( t, v );
+            }
+        } while ( fChange );
+    }
+    if ( pPhase )
+    {
+        *pPhase = 0;
+        for ( v = 0; v < nVars; v++ )
+            *pPhase |= (pCanonPerm[v] << (4 * v));
+        *pPhase |= (CanonPhase << 24);
+    }
+    return t;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    [Computes the hash key.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static inline int Npn_ManHash( Npn_Man_t * p, word uTruth )
+{
+    word Key = (uTruth * (word)101) ^ (uTruth * (word)733) ^ (uTruth * (word)1777);
+    return (int)(Key % (word)p->nBins);
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Resizes the table.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManResize( Npn_Man_t * p )
+{
+    Npn_Obj_t * pEntry, * pNext;
+    int * pBinsOld, * ppPlace;
+    int nBinsOld, Counter, i, clk;
+    assert( p->pBins != NULL );
+clk = clock();
+    // save the old Bins
+    pBinsOld = p->pBins;
+    nBinsOld = p->nBins;
+    // get the new Bins
+    p->nBins = Aig_PrimeCudd( 3 * nBinsOld ); 
+    p->pBins = ABC_CALLOC( int, p->nBins );
+    // rehash the entries from the old table
+    Counter = 1;
+    for ( i = 0; i < nBinsOld; i++ )
+    for ( pEntry = Npn_ManObj(p, pBinsOld[i]), 
+          pNext = pEntry ? Npn_ManObj(p, pEntry->iNext) : NULL; 
+          pEntry; 
+          pEntry = pNext, 
+          pNext = pEntry ? Npn_ManObj(p, pEntry->iNext) : NULL )
+    {
+        // get the place where this entry goes 
+        ppPlace = p->pBins + Npn_ManHash( p, pEntry->uTruth );
+        // add the entry to the list
+        pEntry->iNext = *ppPlace;
+        *ppPlace = Npn_ManObjNum( p, pEntry );
+        Counter++;
+    }
+    assert( Counter == p->nEntries );
+    ABC_FREE( pBinsOld );
+//ABC_PRT( "Hash table resizing time", clock() - clk );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds one entry to the table.]
+
+  Description [Increments ref counter by 1.]
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Npn_Obj_t * Npn_ManAdd( Npn_Man_t * p, word uTruth )
+{
+    Npn_Obj_t * pEntry;
+    int * pPlace, Key = Npn_ManHash( p, uTruth );
+    // resize the link storage if needed
+    if ( p->nEntries == p->nBufferSize )
+    {
+        p->nBufferSize *= 2;
+        p->pBuffer = ABC_REALLOC( Npn_Obj_t, p->pBuffer, p->nBufferSize );
+    }
+    // find the entry
+    for ( pEntry = Npn_ManObj(p, p->pBins[Key]), 
+          pPlace = p->pBins + Key; 
+          pEntry; 
+          pPlace = &pEntry->iNext, 
+          pEntry = Npn_ManObj(p, pEntry->iNext) )
+        if ( pEntry->uTruth == uTruth )
+        {
+            pEntry->Count++;
+            return pEntry;
+        }
+    // create new entry
+    *pPlace = p->nEntries;
+    assert( p->nEntries < p->nBufferSize );
+    pEntry = Npn_ManObj( p, p->nEntries++ );
+    pEntry->uTruth = uTruth;
+    pEntry->Count = 1;
+    pEntry->iNext = 0;
+    // resize the table if needed
+    if ( p->nEntries > 3 * p->nBins )
+        Npn_ManResize( p );
+    return pEntry;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Fills table from file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManRead( Npn_Man_t * p, char * pFileName )
+{
+    char pBuffer[1000];
+    char * pToken;
+    Npn_Obj_t * pEntry;
+    unsigned Truth[2];
+    word uTruth;
+    FILE * pFile = fopen( pFileName, "r" );
+    if ( pFile == NULL )
+    {
+        Abc_Print( -1, "Cannot open NPN function file \"%s\".\n", pFileName );
+        return;
+    }
+    // read lines from the file
+    while ( fgets( pBuffer, 1000, pFile ) != NULL )
+    {
+        pToken = strtok( pBuffer, " \t\n" );
+        if ( pToken == NULL )
+            continue;
+        if ( pToken[0] == '#' )
+            continue;
+        if ( strlen(pToken) != 16 )
+        {
+            Abc_Print( 0, "Skipping token %s that does not look like a 16-digit hex number.\n" );
+            continue;
+        }
+        // extract truth table
+        Extra_ReadHexadecimal( Truth, pToken, 6 );
+        uTruth = (((word)Truth[1]) << 32) | (word)Truth[0];
+        // add truth table
+        pEntry = Npn_ManAdd( p, uTruth );
+        assert( pEntry->Count == 1 );
+        // read area
+        pToken = strtok( NULL, " \t\n" );
+        pEntry->Count = atoi(pToken);
+    }
+    fclose( pFile );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Comparison procedure for two entries.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+static int Npn_ManCompareEntries( Npn_Obj_t ** pp1, Npn_Obj_t ** pp2 )
+{
+    if ( (*pp1)->Count > (*pp2)->Count )
+        return -1;
+    if ( (*pp1)->Count < (*pp2)->Count ) 
+        return 1;
+    return 0; 
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Adds one entry to the table.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManWrite( Npn_Man_t * p, char * pFileName )
+{
+    Vec_Ptr_t * vEntries;
+    Npn_Obj_t * pEntry;
+    FILE * pFile = fopen( pFileName, "w" );
+    int i;
+    if ( pFile == NULL )
+    {
+        Abc_Print( -1, "Cannot open NPN function file \"%s\".\n", pFileName );
+        return;
+    }
+    vEntries = Vec_PtrAlloc( p->nEntries );
+    for ( i = 0; i < p->nBins; i++ )
+        for ( pEntry = Npn_ManObj(p, p->pBins[i]); pEntry; pEntry = Npn_ManObj(p, pEntry->iNext) )
+            Vec_PtrPush( vEntries, pEntry );
+    Vec_PtrSort( vEntries, (int (*)())Npn_ManCompareEntries );
+    Vec_PtrForEachEntry( Npn_Obj_t *, vEntries, pEntry, i )
+    {
+        Extra_PrintHexadecimal( pFile, (unsigned *)&pEntry->uTruth, 6 );
+        fprintf( pFile, " %d %d\n", pEntry->Count, Npn_TruthSuppSize(pEntry->uTruth, 6) );
+    }
+    fclose( pFile );
+    Vec_PtrFree( vEntries );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Creates the manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Npn_Man_t * Npn_ManStart( char * pFileName )
+{
+    Npn_Man_t * p;
+    p = ABC_CALLOC( Npn_Man_t, 1 );
+    if ( pFileName == NULL )
+    {
+        p->nBufferSize = 1000000;
+        p->nBufferSize = 100;
+        p->pBuffer     = ABC_ALLOC( Npn_Obj_t, p->nBufferSize );
+        p->nBins       = Aig_PrimeCudd( p->nBufferSize / 2 );
+        p->pBins       = ABC_CALLOC( int, p->nBins );
+        p->nEntries    = 1;
+    }
+    else
+    {
+        FILE * pFile = fopen( pFileName, "r" );
+        if ( pFile == NULL )
+        {
+            Abc_Print( -1, "Cannot open NPN function file \"%s\".\n", pFileName );
+            return NULL;
+        }
+        fclose( pFile );
+        p->nBufferSize = 4 * ( Extra_FileSize(pFileName) / 20 );
+        p->pBuffer     = ABC_ALLOC( Npn_Obj_t, p->nBufferSize );
+        p->nBins       = Aig_PrimeCudd( p->nBufferSize / 2 );
+        p->pBins       = ABC_CALLOC( int, p->nBins );
+        p->nEntries    = 1;
+        Npn_ManRead( p, pFileName );
+    }
+    return p;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Deletes the manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManStop( Npn_Man_t * p )
+{
+    ABC_FREE( p->pBuffer );
+    ABC_FREE( p->pBins );
+    ABC_FREE( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Cleans the manager.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManClean()
+{
+    if ( pNpnMan != NULL )
+    {
+        Npn_ManStop( pNpnMan );
+        pNpnMan = NULL;
+    }
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Loads functions from a file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManLoad( char * pFileName )
+{
+//    Npn_TruthPermute_rec( "012345", 0, 5 );
+    if ( pNpnMan != NULL )
+    {
+        Abc_Print( 1, "Removing old table with %d entries.\n", pNpnMan->nEntries );
+        Npn_ManStop( pNpnMan );
+    }
+    pNpnMan = Npn_ManStart( pFileName );
+    Abc_Print( 1, "Created new table with %d entries from file \"%s\".\n", pNpnMan->nEntries, pFileName );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Saves functions into a file.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManSave( char * pFileName )
+{
+    if ( pNpnMan == NULL )
+    {
+        Abc_Print( 1, "There is no table with entries.\n" );
+        return;
+    }
+    Npn_ManWrite( pNpnMan, pFileName );
+    Abc_Print( 1, "Dumped table with %d entries from file \"%s\".\n", pNpnMan->nEntries, pFileName );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Saves one function into storage.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Npn_ManSaveOne( unsigned * puTruth, int nVars )
+{
+    word uTruth = (((word)puTruth[1]) << 32) | (word)puTruth[0];
+    assert( nVars >= 0 && nVars <= 6 );
+    if ( pNpnMan == NULL )
+    {
+        Abc_Print( 1, "Creating new table with 0 entries.\n" );
+        pNpnMan = Npn_ManStart( NULL );
+    }
+    // skip truth tables that do not depend on some vars
+    if ( !Npn_TruthIsMinBase( uTruth ) )
+        return;
+    // extend truth table to look like 6-input
+    uTruth = Npn_TruthPadWord( uTruth, nVars );
+    // semi(!)-NPN-canonize the truth table
+    uTruth = Npn_TruthCanon( uTruth, 6, NULL );
+    // add to storage
+    Npn_ManAdd( pNpnMan, uTruth );
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/base/abci/module.make b/src/base/abci/module.make
index b9342881..b0223330 100644
--- a/src/base/abci/module.make
+++ b/src/base/abci/module.make
@@ -34,6 +34,7 @@ SRC +=    src/base/abci/abc.c \
     src/base/abci/abcMiter.c \
     src/base/abci/abcMulti.c \
     src/base/abci/abcNtbdd.c \
+    src/base/abci/abcNpnSave.c \
     src/base/abci/abcOdc.c \
     src/base/abci/abcOrder.c \
     src/base/abci/abcPart.c \