Several updates to FXCH including:

- Cube Grouping
- New sub-cube hash table

src/opt/fxch/Fxch.c

@@ -15,7 +15,6 @@
   Revision    []
 
 ***********************************************************************/
-
 #include "Fxch.h"
 
 ABC_NAMESPACE_IMPL_START
@@ -26,6 +25,125 @@ ABC_NAMESPACE_IMPL_START
 
 /**Function*************************************************************
 
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Fxch_CubesGruping(Fxch_Man_t* pFxchMan)
+{
+    Vec_Int_t* vCube;
+    int iCube;
+
+    /* Identify the number of Outputs and create the translation table */
+    pFxchMan->vTranslation = Vec_IntAlloc( 32 );
+    Vec_WecForEachLevel( pFxchMan->vCubes, vCube, iCube )
+    {
+        int Id = Vec_IntEntry( vCube, 0 );
+        int iTranslation = Vec_IntFind( pFxchMan->vTranslation, Id );
+
+        if ( iTranslation == -1 )
+            Vec_IntPush( pFxchMan->vTranslation, Id );
+    }
+    int nOutputs = Vec_IntSize( pFxchMan->vTranslation );
+
+    /* Size of the OutputID in number o ints */
+    int SizeOutputID = ( nOutputs >> 5 ) + ( ( nOutputs & 31 ) > 0 );
+
+    /* Initialize needed structures */
+    pFxchMan->vOutputID = Vec_IntAlloc( 4096 );
+    pFxchMan->pTempOutputID = ABC_CALLOC( int, SizeOutputID );
+    pFxchMan->nSizeOutputID = SizeOutputID;
+
+    Hsh_VecMan_t* pCubeHash =  Hsh_VecManStart( 1024 );
+
+    /* Identify equal cubes */
+    Vec_WecForEachLevel( pFxchMan->vCubes, vCube, iCube )
+    {
+        int Id = Vec_IntEntry( vCube, 0 );
+        int iTranslation = Vec_IntFind( pFxchMan->vTranslation, Id );
+        Vec_IntWriteEntry( vCube, 0, 0 ); // Clear ID, Outputs will be identified by it later
+
+        int iCubeNoID = Hsh_VecManAdd( pCubeHash, vCube );
+        int Temp = ( 1 << ( iTranslation & 31 ) );
+        if ( iCubeNoID == Vec_IntSize( pFxchMan->vOutputID ) / SizeOutputID )
+        {
+            for ( int i = 0; i < SizeOutputID; i++ )
+                pFxchMan->pTempOutputID[i] = 0;
+
+            pFxchMan->pTempOutputID[ iTranslation >> 5 ] = Temp;
+            Vec_IntPushArray( pFxchMan->vOutputID, pFxchMan->pTempOutputID, SizeOutputID ); 
+        }
+        else
+        {
+            Vec_IntClear( vCube );
+            int* pEntry = Vec_IntEntryP( pFxchMan->vOutputID, ( iCubeNoID * SizeOutputID ) + ( iTranslation >> 5 ) );
+            *pEntry |= Temp;
+        }
+    }
+
+    Hsh_VecManStop( pCubeHash );
+    Vec_WecRemoveEmpty( pFxchMan->vCubes );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Fxch_CubesUnGruping(Fxch_Man_t* pFxchMan)
+{
+    int iCube;
+    int i, j;
+    Vec_Int_t* vCube;
+    Vec_Int_t* vNewCube;
+
+    assert( Vec_WecSize( pFxchMan->vCubes ) == ( Vec_IntSize( pFxchMan->vOutputID ) / pFxchMan->nSizeOutputID ) );
+    Vec_WecForEachLevel( pFxchMan->vCubes, vCube, iCube )
+    {
+        if ( Vec_IntSize( vCube ) == 0 || Vec_IntEntry( vCube, 0 ) != 0 )
+            continue;
+
+        int* pOutputID = Vec_IntEntryP( pFxchMan->vOutputID, iCube * pFxchMan->nSizeOutputID );
+        int nOnes = 0;
+
+        for ( i = 0; i < pFxchMan->nSizeOutputID; i++ )
+            nOnes += Fxch_CountOnes( (unsigned int) pOutputID[i] );
+
+        for ( i = 0; i < pFxchMan->nSizeOutputID && nOnes; i++ )
+            for ( j = 0; j < 32 && nOnes; j++ )
+                if ( pOutputID[i] & ( 1 << j ) )
+                {
+                    if ( nOnes == 1 )
+                        Vec_IntWriteEntry( vCube, 0, Vec_IntEntry( pFxchMan->vTranslation, ( i << 5 ) | j ) );
+                    else
+                    {
+                        vNewCube = Vec_WecPushLevel( pFxchMan->vCubes );
+                        Vec_IntAppend( vNewCube, vCube );
+                        Vec_IntWriteEntry( vNewCube, 0, Vec_IntEntry( pFxchMan->vTranslation, (i << 5 ) | j ) );
+                    }
+                    nOnes -= 1;
+                }
+    }
+
+    Vec_IntFree( pFxchMan->vTranslation );
+    Vec_IntFree( pFxchMan->vOutputID );
+    ABC_FREE( pFxchMan->pTempOutputID );
+    return;
+}
+
+/**Function*************************************************************
+
   Synopsis    [ Performs fast extract with cube hashing on a set
                 of covers. ]
 
@@ -47,6 +165,7 @@ int Fxch_FastExtract( Vec_Wec_t* vCubes,
     int i;
 
     TempTime = Abc_Clock();
+    Fxch_CubesGruping( pFxchMan );
     Fxch_ManMapLiteralsIntoCubes( pFxchMan, ObjIdMax );
     Fxch_ManGenerateLitHashKeys( pFxchMan );
     Fxch_ManComputeLevel( pFxchMan );
@@ -61,6 +180,7 @@ int Fxch_FastExtract( Vec_Wec_t* vCubes,
         Fxch_ManPrintStats( pFxchMan );
 
     TempTime = Abc_Clock();
+    
     for ( i = 0; (!nMaxDivExt || i < nMaxDivExt) && Vec_QueTopPriority( pFxchMan->vDivPrio ) > 0.0; i++ )
     {
         int iDiv = Vec_QuePop( pFxchMan->vDivPrio );
@@ -70,6 +190,7 @@ int Fxch_FastExtract( Vec_Wec_t* vCubes,
 
         Fxch_ManUpdate( pFxchMan, iDiv );
     }
+   
     pFxchMan->timeExt = Abc_Clock() - TempTime;
 
     if ( fVerbose )
@@ -80,9 +201,12 @@ int Fxch_FastExtract( Vec_Wec_t* vCubes,
         Abc_PrintTime( 1, "[FXCH]    +-> Extr", pFxchMan->timeExt );
     }
 
+    Fxch_CubesUnGruping( pFxchMan );
     Fxch_ManSCHashTablesFree( pFxchMan );
     Fxch_ManFree( pFxchMan );
+
     Vec_WecRemoveEmpty( vCubes );
+    Vec_WecSortByFirstInt( vCubes, 0 );
 
     return 1;
 }

src/opt/fxch/Fxch.h

@@ -52,25 +52,22 @@ typedef struct Fxch_SCHashTable_Entry_t_ Fxch_SCHashTable_Entry_t;
  *   its literals.
  *
  */
+
 struct Fxch_SubCube_t_
 {
-    unsigned int Id,
-                 iCube;
-    unsigned int iLit0 : 16,
-                 iLit1 : 16;
+    uint32_t Id,
+             iCube;
+    uint32_t iLit0 : 16,
+             iLit1 : 16;
 };
 
 /* Sub-cube Hash Table
- *
  */
 struct Fxch_SCHashTable_Entry_t_
 {
-    Fxch_SubCube_t SCData;
-
-    unsigned int iTable : 31,
-                 Used   :  1;
-    unsigned int iPrev,
-                 iNext;
+    Fxch_SubCube_t* vSCData;
+    uint32_t Size : 16,
+             Cap : 16;
 };
 
 struct Fxch_SCHashTable_t_
@@ -80,7 +77,6 @@ struct Fxch_SCHashTable_t_
     Fxch_SCHashTable_Entry_t* pBins;
     unsigned int nEntries,
                  SizeMask;
-    Vec_Int_t*   vCubeLinks;
 
     /* Temporary data */
     Vec_Int_t    vSubCube0;
@@ -91,6 +87,7 @@ struct Fxch_Man_t_
 {
     /* user's data */
     Vec_Wec_t* vCubes;
+    int nCubesInit;
     int LitCountMax;
 
     /* internal data */
@@ -107,12 +104,21 @@ struct Fxch_Man_t_
 
     Vec_Int_t*    vLevels;       /* variable levels */
 
+    // Cube Grouping
+    Vec_Int_t* vTranslation;
+    Vec_Int_t* vOutputID;
+    int* pTempOutputID;
+    int  nSizeOutputID;
+
     // temporary data to update the data-structure when a divisor is extracted
-    Vec_Int_t*     vCubesS;     /* cubes for the given single cube divisor */
-    Vec_Int_t*     vPairs;     /* cube pairs for the given double cube divisor */
-    Vec_Int_t*     vCubeFree;  // cube-free divisor
-    Vec_Int_t*     vDiv;       // selected divisor
-    Vec_Int_t*     vSCC;
+    Vec_Int_t* vCubesS;    /* cubes for the given single cube divisor */
+    Vec_Int_t* vPairs;     /* cube pairs for the given double cube divisor */
+    Vec_Int_t* vCubeFree;  // cube-free divisor
+    Vec_Int_t* vDiv;       // selected divisor
+
+    Vec_Int_t* vCubesToRemove;
+    Vec_Int_t* vCubesToUpdate;
+    Vec_Int_t* vSCC;
 
     /* Statistics */
     abctime timeInit;   /* Initialization time */
@@ -135,6 +141,15 @@ extern Vec_Wec_t* Abc_NtkFxRetrieve( Abc_Ntk_t* pNtk );
 extern void       Abc_NtkFxInsert( Abc_Ntk_t* pNtk, Vec_Wec_t* vCubes );
 extern int        Abc_NtkFxCheck( Abc_Ntk_t* pNtk );
 
+static inline int Fxch_CountOnes( unsigned num )
+{
+    num = ( num & 0x55555555 ) + ( ( num >> 1) & 0x55555555 );
+    num = ( num & 0x33333333 ) + ( ( num >> 2) & 0x33333333 );
+    num = ( num & 0x0F0F0F0F ) + ( ( num >> 4) & 0x0F0F0F0F );
+    num = ( num & 0x00FF00FF ) + ( ( num >> 8) & 0x00FF00FF );
+    return  ( num & 0x0000FFFF ) + ( num >> 16 );
+}
+
 /*===== Fxch.c =======================================================*/
 int Abc_NtkFxchPerform( Abc_Ntk_t* pNtk, int nMaxDivExt, int fVerbose, int fVeryVerbose );
 int Fxch_FastExtract( Vec_Wec_t* vCubes, int ObjIdMax, int nMaxDivExt, int fVerbose, int fVeryVerbose );
@@ -177,26 +192,25 @@ static inline int Fxch_ManGetLit( Fxch_Man_t* pFxchMan,
 }
 
 /*===== FxchSCHashTable.c ============================================*/
-Fxch_SCHashTable_t* Fxch_SCHashTableCreate( Fxch_Man_t* pFxchMan, Vec_Int_t* vCubeLinks, int nEntries );
+Fxch_SCHashTable_t* Fxch_SCHashTableCreate( Fxch_Man_t* pFxchMan, int nEntries );
 
 void Fxch_SCHashTableDelete( Fxch_SCHashTable_t* );
 
 int Fxch_SCHashTableInsert( Fxch_SCHashTable_t* pSCHashTable,
                             Vec_Wec_t* vCubes,
-                            unsigned int SubCubeID,
-                            unsigned int iSubCube,
-                            unsigned int iCube,
-                            unsigned int iLit0,
-                            unsigned int iLit1,
+                            uint32_t SubCubeID,
+                            uint32_t iCube,
+                            uint32_t iLit0,
+                            uint32_t iLit1,
                             char fUpdate );
 
+
 int Fxch_SCHashTableRemove( Fxch_SCHashTable_t* pSCHashTable,
                             Vec_Wec_t* vCubes,
-                            unsigned int SubCubeID,
-                            unsigned int iSubCube,
-                            unsigned int iCube,
-                            unsigned int iLit0,
-                            unsigned int iLit1,
+                            uint32_t SubCubeID,
+                            uint32_t iCube,
+                            uint32_t iLit0,
+                            uint32_t iLit1,
                             char fUpdate );
 
 unsigned int Fxch_SCHashTableMemory( Fxch_SCHashTable_t* );

src/opt/fxch/FxchDiv.c

@@ -142,10 +142,20 @@ int Fxch_DivCreate( Fxch_Man_t* pFxchMan,
         SC0_Lit1 = Fxch_ManGetLit( pFxchMan, pSubCube0->iCube, pSubCube0->iLit1 );
         SC1_Lit1 = Fxch_ManGetLit( pFxchMan, pSubCube1->iCube, pSubCube1->iLit1 );
 
-        Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit0, 0 ) );
-        Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit0, 1 ) );
-        Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit1, 0 ) );
-        Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit1, 1 ) );
+        if ( SC0_Lit0 < SC1_Lit0 )
+        {
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit0, 0 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit0, 1 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit1, 0 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit1, 1 ) );
+        }
+        else
+        {
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit0, 0 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit0, 1 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC1_Lit1, 0 ) );
+            Vec_IntPush( pFxchMan->vCubeFree, Abc_Var2Lit( SC0_Lit1, 1 ) );
+        }
 
         RetValue = Fxch_DivNormalize( pFxchMan->vCubeFree );
         if ( RetValue == -1 )