Version abc80126

Makefile

@@ -23,8 +23,8 @@ MODULES := src/base/abc src/base/abci src/base/cmd \
 
 default: $(PROG)
 
-#OPTFLAGS  := -DNDEBUG -O3
-OPTFLAGS  := -g -O
+OPTFLAGS  := -DNDEBUG -O3
+#OPTFLAGS  := -g -O
 
 CFLAGS   += -Wall -Wno-unused-function $(OPTFLAGS) $(patsubst %, -I%, $(MODULES)) 
 CXXFLAGS += $(CFLAGS) 

abc.dsp

@@ -1608,6 +1608,10 @@ SOURCE=.\src\opt\fret\fretInit.c
 
 SOURCE=.\src\opt\fret\fretMain.c
 # End Source File
+# Begin Source File
+
+SOURCE=.\src\opt\fret\fretTime.c
+# End Source File
 # End Group
 # End Group
 # Begin Group "map"
@@ -2854,6 +2858,10 @@ SOURCE=.\src\aig\aig\aigCheck.c
 # End Source File
 # Begin Source File
 
+SOURCE=.\src\aig\aig\aigCuts.c
+# End Source File
+# Begin Source File
+
 SOURCE=.\src\aig\aig\aigDfs.c
 # End Source File
 # Begin Source File

src/aig/aig/aig.h

@@ -137,6 +137,7 @@ struct Aig_Man_t_
     void (*pImpFunc) (void*, void*); // implication checking precedure
     void *           pImpData;       // implication checking data
     void *           pManTime;       // the timing manager
+    void *           pManCuts;
     Vec_Ptr_t *      vMapped;
     Vec_Int_t *      vFlopNums;      
     void *           pSeqModel;
@@ -146,6 +147,56 @@ struct Aig_Man_t_
     int              time2;
 };
 
+// cut computation
+typedef struct Aig_ManCut_t_         Aig_ManCut_t;
+typedef struct Aig_Cut_t_            Aig_Cut_t;
+
+// the cut used to represent node in the AIG
+struct Aig_Cut_t_
+{
+    Aig_Cut_t *     pNext;           // the next cut in the table 
+    int             Cost;            // the cost of the cut
+    unsigned        uSign;           // cut signature
+    int             iNode;           // the node, for which it is the cut
+    short           nCutSize;        // the number of bytes in the cut
+    char            nLeafMax;        // the maximum number of fanins
+    char            nFanins;         // the current number of fanins
+    int             pFanins[0];      // the fanins (followed by the truth table)
+};
+
+// the CNF computation manager
+struct Aig_ManCut_t_
+{
+    // AIG manager
+    Aig_Man_t *     pAig;            // the input AIG manager
+    Aig_Cut_t **    pCuts;           // the cuts for each node in the output manager
+    // parameters
+    int             nCutsMax;        // the max number of cuts at the node
+    int             nLeafMax;        // the max number of leaves of a cut
+    int             fTruth;          // enables truth table computation
+    int             fVerbose;        // enables verbose output
+    // internal variables
+    int             nCutSize;        // the number of bytes needed to store one cut
+    int             nTruthWords;     // the number of truth table words
+    Aig_MmFixed_t * pMemCuts;        // memory manager for cuts
+    unsigned *      puTemp[4];       // used for the truth table computation
+};
+
+static inline Aig_Cut_t *  Aig_ObjCuts( Aig_ManCut_t * p, Aig_Obj_t * pObj )                         { return p->pCuts[pObj->Id];  }
+static inline void         Aig_ObjSetCuts( Aig_ManCut_t * p, Aig_Obj_t * pObj, Aig_Cut_t * pCuts )   { p->pCuts[pObj->Id] = pCuts; }
+
+static inline int          Aig_CutLeaveNum( Aig_Cut_t * pCut )          { return pCut->nFanins;                                    }
+static inline int *        Aig_CutLeaves( Aig_Cut_t * pCut )            { return pCut->pFanins;                                    }
+static inline unsigned *   Aig_CutTruth( Aig_Cut_t * pCut )             { return (unsigned *)(pCut->pFanins + pCut->nLeafMax);     }
+static inline Aig_Cut_t *  Aig_CutNext( Aig_Cut_t * pCut )              { return (Aig_Cut_t *)(((char *)pCut) + pCut->nCutSize);   }
+
+// iterator over cuts of the node
+#define Aig_ObjForEachCut( p, pObj, pCut, i )                           \
+    for ( i = 0, pCut = Aig_ObjCuts(p, pObj); i < p->nCutsMax; i++, pCut = Aig_CutNext(pCut) ) 
+// iterator over leaves of the cut
+#define Aig_CutForEachLeaf( p, pCut, pLeaf, i )                         \
+    for ( i = 0; (i < (int)(pCut)->nFanins) && ((pLeaf) = Aig_ManObj(p, (pCut)->pFanins[i])); i++ )
+
 ////////////////////////////////////////////////////////////////////////
 ///                      MACRO DEFINITIONS                           ///
 ////////////////////////////////////////////////////////////////////////
@@ -386,6 +437,9 @@ static inline int     Aig_ObjFanoutNext( Aig_Man_t * p, int iFan )   { assert(iF
 extern int             Aig_ManCheck( Aig_Man_t * p );
 extern void            Aig_ManCheckMarkA( Aig_Man_t * p );
 extern void            Aig_ManCheckPhase( Aig_Man_t * p );
+/*=== aigCuts.c ========================================================*/
+extern Aig_ManCut_t *  Aig_ComputeCuts( Aig_Man_t * pAig, int nCutsMax, int nLeafMax, int fTruth, int fVerbose );
+extern void            Aig_ManCutStop( Aig_ManCut_t * p );
 /*=== aigDfs.c ==========================================================*/
 extern Vec_Ptr_t *     Aig_ManDfs( Aig_Man_t * p );
 extern Vec_Ptr_t *     Aig_ManDfsPio( Aig_Man_t * p );

src/aig/cnf/cnfCore.c

@@ -57,7 +57,7 @@ Cnf_Dat_t * Cnf_Derive( Aig_Man_t * pAig, int nOutputs )
 
     // generate cuts for all nodes, assign cost, and find best cuts
 clk = clock();
-    pMemCuts = Dar_ManComputeCuts( pAig, 10 );
+    pMemCuts = Dar_ManComputeCuts( pAig, 10, 0 );
 p->timeCuts = clock() - clk;
 
     // find the mapping

src/aig/dar/dar.h

@@ -83,7 +83,7 @@ extern Aig_Man_t *     Dar_ManBalance( Aig_Man_t * p, int fUpdateLevel );
 /*=== darCore.c ========================================================*/
 extern void            Dar_ManDefaultRwrParams( Dar_RwrPar_t * pPars );
 extern int             Dar_ManRewrite( Aig_Man_t * pAig, Dar_RwrPar_t * pPars );
-extern Aig_MmFixed_t * Dar_ManComputeCuts( Aig_Man_t * pAig, int nCutsMax );
+extern Aig_MmFixed_t * Dar_ManComputeCuts( Aig_Man_t * pAig, int nCutsMax, int fVerbose );
 /*=== darRefact.c ========================================================*/
 extern void            Dar_ManDefaultRefParams( Dar_RefPar_t * pPars );
 extern int             Dar_ManRefactor( Aig_Man_t * pAig, Dar_RefPar_t * pPars );

src/aig/dar/darCore.c

@@ -195,6 +195,34 @@ p->timeOther = p->timeTotal - p->timeCuts - p->timeEval;
 
 /**Function*************************************************************
 
+  Synopsis    [Computes the total number of cuts.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Dar_ManCutCount( Aig_Man_t * pAig, int * pnCutsK )
+{
+    Dar_Cut_t * pCut;
+    Aig_Obj_t * pObj;
+    int i, k, nCuts = 0, nCutsK = 0;
+    Aig_ManForEachNode( pAig, pObj, i )
+        Dar_ObjForEachCut( pObj, pCut, k )
+        {
+            nCuts++;
+            if ( pCut->nLeaves == 4 )
+                nCutsK++;
+        }
+    if ( pnCutsK )
+        *pnCutsK = nCutsK;
+    return nCuts;
+}
+
+/**Function*************************************************************
+
   Synopsis    []
 
   Description []
@@ -204,13 +232,13 @@ p->timeOther = p->timeTotal - p->timeCuts - p->timeEval;
   SeeAlso     []
 
 ***********************************************************************/
-Aig_MmFixed_t * Dar_ManComputeCuts( Aig_Man_t * pAig, int nCutsMax )
+Aig_MmFixed_t * Dar_ManComputeCuts( Aig_Man_t * pAig, int nCutsMax, int fVerbose )
 {
     Dar_Man_t * p;
     Dar_RwrPar_t Pars, * pPars = &Pars; 
     Aig_Obj_t * pObj;
     Aig_MmFixed_t * pMemCuts;
-    int i, nNodes;
+    int i, nNodes, clk = clock();
     // remove dangling nodes
     if ( (nNodes = Aig_ManCleanup( pAig )) )
     {
@@ -226,6 +254,23 @@ Aig_MmFixed_t * Dar_ManComputeCuts( Aig_Man_t * pAig, int nCutsMax )
     // compute cuts for each nodes in the topological order
     Aig_ManForEachNode( pAig, pObj, i )
         Dar_ObjComputeCuts( p, pObj );
+    // print verbose stats
+    if ( fVerbose )
+    {
+//        Aig_Obj_t * pObj;
+        int nCuts, nCutsK;//, i;
+        nCuts = Dar_ManCutCount( pAig, &nCutsK );
+        printf( "Nodes = %6d. Total cuts = %6d. 4-input cuts = %6d.\n",
+            Aig_ManObjNum(pAig), nCuts, nCutsK );
+        printf( "Cut size = %2d. Truth size = %2d. Total mem = %5.2f Mb  ",
+            sizeof(Dar_Cut_t), 4, 1.0*Aig_MmFixedReadMemUsage(p->pMemCuts)/(1<<20) );
+        PRT( "Runtime", clock() - clk );
+/*
+        Aig_ManForEachNode( pAig, pObj, i )
+            if ( i % 300 == 0 )
+                Dar_ObjCutPrint( pAig, pObj );
+*/
+    }
     // free the cuts
     pMemCuts = p->pMemCuts;
     p->pMemCuts = NULL;

src/aig/dar/darCut.c

@@ -30,6 +30,47 @@
 
 /**Function*************************************************************
 
+  Synopsis    [Prints one cut.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Dar_CutPrint( Dar_Cut_t * pCut )
+{
+    unsigned i;
+    printf( "{" );
+    for ( i = 0; i < pCut->nLeaves; i++ )
+        printf( " %d", pCut->pLeaves[i] );
+    printf( " }\n" );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Prints one cut.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Dar_ObjCutPrint( Aig_Man_t * p, Aig_Obj_t * pObj )
+{
+    Dar_Cut_t * pCut;
+    int i;
+    printf( "Cuts for node %d:\n", pObj->Id );
+    Dar_ObjForEachCut( pObj, pCut, i )
+        Dar_CutPrint( pCut );
+//    printf( "\n" );
+}
+
+/**Function*************************************************************
+
   Synopsis    [Returns the number of 1s in the machine word.]
 
   Description []

src/aig/dar/darInt.h

@@ -134,6 +134,7 @@ extern void            Dar_ManCutsStart( Dar_Man_t * p );
 extern void            Dar_ManCutsFree( Dar_Man_t * p );
 extern Dar_Cut_t *     Dar_ObjComputeCuts_rec( Dar_Man_t * p, Aig_Obj_t * pObj );
 extern Dar_Cut_t *     Dar_ObjComputeCuts( Dar_Man_t * p, Aig_Obj_t * pObj );
+extern void            Dar_ObjCutPrint( Aig_Man_t * p, Aig_Obj_t * pObj );
 /*=== darData.c ===========================================================*/
 extern Vec_Int_t *     Dar_LibReadNodes();
 extern Vec_Int_t *     Dar_LibReadOuts();

src/base/abc/1.txt

+Comparing files abcDfs.c and C:\_PROJECTS\AARON\FRETIME\SRC\BASE\ABC\ABCDFS.C
+***** abcDfs.c
+        return pNode->Level;
+    assert( Abc_ObjIsNode( pNode ) );
+    // if this node is already visited, return
+***** C:\_PROJECTS\AARON\FRETIME\SRC\BASE\ABC\ABCDFS.C
+        return pNode->Level;
+    assert( Abc_ObjIsNode( pNode ) || pNode->Type == ABC_OBJ_CONST1);
+    // if this node is already visited, return
+*****
+
+***** abcDfs.c
+        return pNode->Level;
+    assert( Abc_ObjIsNode( pNode ) );
+    // if this node is already visited, return
+***** C:\_PROJECTS\AARON\FRETIME\SRC\BASE\ABC\ABCDFS.C
+        return pNode->Level;
+    assert( Abc_ObjIsNode( pNode ) || pNode->Type == ABC_OBJ_CONST1);
+    // if this node is already visited, return
+*****
+

src/base/abc/abcDfs.c

@@ -908,7 +908,7 @@ int Abc_NtkLevel_rec( Abc_Obj_t * pNode )
     // skip the PI
     if ( Abc_ObjIsCi(pNode) )
         return pNode->Level;
-    assert( Abc_ObjIsNode( pNode ) );
+    assert( Abc_ObjIsNode( pNode ) || pNode->Type == ABC_OBJ_CONST1);
     // if this node is already visited, return
     if ( Abc_NodeIsTravIdCurrent( pNode ) )
         return pNode->Level;
@@ -946,7 +946,7 @@ int Abc_NtkLevelReverse_rec( Abc_Obj_t * pNode )
     // skip the PI
     if ( Abc_ObjIsCo(pNode) )
         return pNode->Level;
-    assert( Abc_ObjIsNode( pNode ) );
+    assert( Abc_ObjIsNode( pNode ) || pNode->Type == ABC_OBJ_CONST1);
     // if this node is already visited, return
     if ( Abc_NodeIsTravIdCurrent( pNode ) )
         return pNode->Level;

src/base/abci/abc.c

@@ -6392,8 +6392,8 @@ int Abc_CommandTest( Abc_Frame_t * pAbc, int argc, char ** argv )
     pOut = Abc_FrameReadOut(pAbc);
     pErr = Abc_FrameReadErr(pAbc);
 
-//    printf( "This command is temporarily disabled.\n" );
-//    return 0;
+    printf( "This command is temporarily disabled.\n" );
+    return 0;
 
     // set defaults
     fVeryVerbose = 0;
@@ -13402,27 +13402,37 @@ int Abc_CommandIndcut( Abc_Frame_t * pAbc, int argc, char ** argv )
     int nFrames;
     int nPref;
     int nClauses;
+    int nLutSize;
+    int nLevels;
+    int nCutsMax;
+    int nBatches;
+    int fStepUp;
     int fBmc;
     int fRegs;
     int fVerbose;
     int fVeryVerbose;
     int c;
-    extern int Abc_NtkDarClau( Abc_Ntk_t * pNtk, int nFrames, int nPref, int nClauses, int fBmc, int fRegs, int fVerbose, int fVeryVerbose );
+    extern int Abc_NtkDarClau( Abc_Ntk_t * pNtk, int nFrames, int nPref, int nClauses, int nLutSize, int nLevels, int nCutsMax, int nBatches, int fStepUp, int fBmc, int fRegs, int fVerbose, int fVeryVerbose );
 
     pNtk = Abc_FrameReadNtk(pAbc);
     pOut = Abc_FrameReadOut(pAbc);
     pErr = Abc_FrameReadErr(pAbc);
 
     // set defaults
-    nFrames      = 1;
-    nPref        = 0;
+    nFrames      =    1;
+    nPref        =    0;
     nClauses     = 5000;
-    fBmc         = 1;
-    fRegs        = 1;
-    fVerbose     = 0;
-    fVeryVerbose = 0;
+    nLutSize     =    4;
+    nLevels      =    8;
+    nCutsMax     =   16;
+    nBatches     =    1;
+    fStepUp      =    0;
+    fBmc         =    1;
+    fRegs        =    1;
+    fVerbose     =    0;
+    fVeryVerbose =    0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "FPCbrvwh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "FPCMLNBsbrvwh" ) ) != EOF )
     {
         switch ( c )
         {
@@ -13459,6 +13469,53 @@ int Abc_CommandIndcut( Abc_Frame_t * pAbc, int argc, char ** argv )
             if ( nClauses < 0 ) 
                 goto usage;
             break;
+        case 'M':
+            if ( globalUtilOptind >= argc )
+            {
+                fprintf( pErr, "Command line switch \"-K\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nLutSize = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nLutSize < 0 ) 
+                goto usage;
+            break;
+        case 'L':
+            if ( globalUtilOptind >= argc )
+            {
+                fprintf( pErr, "Command line switch \"-L\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nLevels = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nLevels < 0 ) 
+                goto usage;
+            break;
+        case 'N':
+            if ( globalUtilOptind >= argc )
+            {
+                fprintf( pErr, "Command line switch \"-N\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nCutsMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nCutsMax < 0 ) 
+                goto usage;
+            break;
+        case 'B':
+            if ( globalUtilOptind >= argc )
+            {
+                fprintf( pErr, "Command line switch \"-B\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nBatches = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nBatches < 0 ) 
+                goto usage;
+            break;
+        case 's':
+            fStepUp ^= 1;
+            break;
         case 'b':
             fBmc ^= 1;
             break;
@@ -13492,14 +13549,24 @@ int Abc_CommandIndcut( Abc_Frame_t * pAbc, int argc, char ** argv )
         fprintf( stdout, "Currently only works for structurally hashed circuits.\n" );
         return 0;
     }
-    Abc_NtkDarClau( pNtk, nFrames, nPref, nClauses, fBmc, fRegs, fVerbose, fVeryVerbose );
+    if ( nLutSize > 12 )
+    {
+        fprintf( stdout, "The cut size should be not exceed 12.\n" );
+        return 0;
+    }
+    Abc_NtkDarClau( pNtk, nFrames, nPref, nClauses, nLutSize, nLevels, nCutsMax, nBatches, fStepUp, fBmc, fRegs, fVerbose, fVeryVerbose );
     return 0;
 usage:
-    fprintf( pErr, "usage: indcut [-F num] [-P num] [-C num] [-bvh]\n" );
+    fprintf( pErr, "usage: indcut [-FPCMLNB num] [-bvh]\n" );
     fprintf( pErr, "\t         K-step induction strengthened with cut properties\n" );
     fprintf( pErr, "\t-F num : number of time frames for induction (1=simple) [default = %d]\n", nFrames );
     fprintf( pErr, "\t-P num : number of time frames in the prefix (0=no prefix) [default = %d]\n", nPref );
     fprintf( pErr, "\t-C num : the max number of clauses to use for strengthening [default = %d]\n", nClauses );
+    fprintf( pErr, "\t-M num : the cut size (2 <= M <= 12) [default = %d]\n", nLutSize );
+    fprintf( pErr, "\t-L num : the max number of levels for cut computation [default = %d]\n", nLevels );
+    fprintf( pErr, "\t-N num : the max number of cuts to compute at a node [default = %d]\n", nCutsMax );
+    fprintf( pErr, "\t-B num : the max number of invariant batches to try [default = %d]\n", nBatches );
+    fprintf( pErr, "\t-s     : toggle increment cut size in each batch [default = %s]\n", fStepUp? "yes": "no" );
     fprintf( pErr, "\t-b     : toggle enabling BMC check [default = %s]\n", fBmc? "yes": "no" );
     fprintf( pErr, "\t-r     : toggle enabling register clauses [default = %s]\n", fRegs? "yes": "no" );
     fprintf( pErr, "\t-v     : toggle printing verbose information [default = %s]\n", fVerbose? "yes": "no" );

src/base/abci/abcDar.c

@@ -1433,10 +1433,10 @@ int Abc_NtkDarSeqSim( Abc_Ntk_t * pNtk, int nFrames, int nWords, int fVerbose )
   SeeAlso     []
 
 ***********************************************************************/
-int Abc_NtkDarClau( Abc_Ntk_t * pNtk, int nFrames, int nPref, int nClauses, int fBmc, int fRefs, int fVerbose, int fVeryVerbose )
+int Abc_NtkDarClau( Abc_Ntk_t * pNtk, int nFrames, int nPref, int nClauses, int nLutSize, int nLevels, int nCutsMax, int nBatches, int fStepUp, int fBmc, int fRefs, int fVerbose, int fVeryVerbose )
 {
     extern int Fra_Clau( Aig_Man_t * pMan, int nIters, int fVerbose, int fVeryVerbose );
-    extern int Fra_Claus( Aig_Man_t * pAig, int nFrames, int nPref, int nClauses, int fBmc, int fRefs, int fVerbose, int fVeryVerbose );
+    extern int Fra_Claus( Aig_Man_t * pAig, int nFrames, int nPref, int nClauses, int nLutSize, int nLevels, int nCutsMax, int nBatches, int fStepUp, int fBmc, int fRefs, int fVerbose, int fVeryVerbose );
     Aig_Man_t * pMan;
     if ( Abc_NtkPoNum(pNtk) != 1 )
     {
@@ -1452,7 +1452,7 @@ int Abc_NtkDarClau( Abc_Ntk_t * pNtk, int nFrames, int nPref, int nClauses, int
     pMan->vFlopNums = NULL;
 
 //    Fra_Clau( pMan, nStepsMax, fVerbose, fVeryVerbose );
-    Fra_Claus( pMan, nFrames, nPref, nClauses, fBmc, fRefs, fVerbose, fVeryVerbose );
+    Fra_Claus( pMan, nFrames, nPref, nClauses, nLutSize, nLevels, nCutsMax, nBatches, fStepUp, fBmc, fRefs, fVerbose, fVeryVerbose );
     Aig_ManStop( pMan );
     return 1;
 }

src/opt/fret/fretime.h

@@ -23,7 +23,7 @@
 
 #include "abc.h"
 
-#define IGNORE_TIMING
+// #define IGNORE_TIMING
 // #define DEBUG_PRINT_FLOWS
 // #define DEBUG_VISITED
 // #define DEBUG_PREORDER
@@ -45,49 +45,29 @@
 #define INIT_0          0x20
 #define INIT_1          0x40
 #define INIT_CARE (INIT_0 | INIT_1)
+#define CONSERVATIVE    0x80
+#define BLOCK_OR_CONS (BLOCK | CONSERVATIVE)
 
-typedef struct Untimed_Flow_Data_t_ {
-  unsigned int mark : 8;
+typedef struct Flow_Data_t_ {
+  unsigned int mark : 16;
 
   union {
     Abc_Obj_t   *pred;
     /* unsigned int var; */
     Abc_Obj_t   *pInitObj;
+    Vec_Ptr_t   *vNodes;
   };
 
   unsigned int e_dist : 16;
   unsigned int r_dist : 16;
-} Untimed_Flow_Data_t;
-
-typedef struct Timed_Flow_Data_t_ {
-  unsigned int mark : 8;
-
-  union {
-    Abc_Obj_t   *pred;
-    Vec_Ptr_t   *vTimeInEdges;
-    /* unsigned int var; */
-    Abc_Obj_t   *pInitObj;
-  };
-
-  unsigned int e_dist : 16;
-  unsigned int r_dist : 16;
-
-  Vec_Ptr_t    vTimeEdges;
-
-} Timed_Flow_Data_t;
-
-#if defined(IGNORE_TIMING)
-typedef Untimed_Flow_Data_t Flow_Data_t;
-#else
-typedef Timed_Flow_Data_t Flow_Data_t;
-#endif
+} Flow_Data_t;
 
 // useful macros for manipulating Flow_Data structure...
 #define FDATA( x )     ((Flow_Data_t *)Abc_ObjCopy(x))
 #define FSET( x, y )   ((Flow_Data_t *)Abc_ObjCopy(x))->mark |= y
 #define FUNSET( x, y ) ((Flow_Data_t *)Abc_ObjCopy(x))->mark &= ~y
 #define FTEST( x, y )  (((Flow_Data_t *)Abc_ObjCopy(x))->mark & y)
-#define FTIMEEDGES( x )  &(((Timed_Flow_Data_t *)Abc_ObjCopy(x))->vTimeEdges)
+#define FTIMEEDGES( x )  &(pManMR->vTimeEdges[Abc_ObjId( x )])
 
 static inline void FSETPRED(Abc_Obj_t *pObj, Abc_Obj_t *pPred) {
   assert(!Abc_ObjIsLatch(pObj)); // must preserve field to maintain init state linkage
@@ -97,21 +77,56 @@ static inline Abc_Obj_t * FGETPRED(Abc_Obj_t *pObj) {
   return FDATA(pObj)->pred;
 }
 
+
+typedef struct MinRegMan_t_ {
+ 
+  // problem description:
+  int         maxDelay;
+  bool        fComputeInitState, fGuaranteeInitState;
+  int         nNodes, nLatches;
+  bool        fForwardOnly, fBackwardOnly;
+  bool        fConservTimingOnly;
+  int         nMaxIters;
+  bool        fVerbose;
+  Abc_Ntk_t  *pNtk;
+
+  int         nPreRefine;
+
+  // problem state
+  bool        fIsForward;
+  bool        fSinkDistTerminate;
+  int         nExactConstraints, nConservConstraints;
+  int         fSolutionIsDc;
+  int         constraintMask;
+  int         iteration, subIteration;
+  
+  // problem data
+  Vec_Int_t   *vSinkDistHist;
+  Flow_Data_t *pDataArray;
+  Vec_Ptr_t   *vTimeEdges;
+  Vec_Ptr_t   *vExactNodes;
+  Abc_Ntk_t   *pInitNtk;
+  Vec_Ptr_t   *vNodes; // re-useable struct
+
+} MinRegMan_t ;
+
+#define vprintf if (pManMR->fVerbose) printf 
+
 /*=== fretMain.c ==========================================================*/
+ 
+extern MinRegMan_t *pManMR;
 
 Abc_Ntk_t *    Abc_FlowRetime_MinReg( Abc_Ntk_t * pNtk, int fVerbose, int fComputeInitState,
                                       int fForward, int fBackward, int nMaxIters,
-                                      int maxDelay);
+                                      int maxDelay, int fFastButConservative);
 
 void print_node(Abc_Obj_t *pObj);
 
 void Abc_ObjBetterTransferFanout( Abc_Obj_t * pFrom, Abc_Obj_t * pTo, int compl );
 
-extern int         fIsForward;
-extern int         fSinkDistTerminate;
-extern Vec_Int_t  *vSinkDistHist;
-extern int         maxDelayCon;
-extern int         fComputeInitState;
+int  Abc_FlowRetime_PushFlows( Abc_Ntk_t * pNtk, bool fVerbose );
+bool Abc_FlowRetime_IsAcrossCut( Abc_Obj_t *pCur, Abc_Obj_t *pNext );
+void Abc_FlowRetime_ClearFlows( bool fClearAll );
 
 /*=== fretFlow.c ==========================================================*/
 
@@ -132,9 +147,19 @@ void Abc_FlowRetime_UpdateForwardInit( Abc_Ntk_t * pNtk );
 void Abc_FlowRetime_UpdateBackwardInit( Abc_Ntk_t * pNtk );
 
 void Abc_FlowRetime_SetupBackwardInit( Abc_Ntk_t * pNtk );
-void Abc_FlowRetime_SolveBackwardInit( Abc_Ntk_t * pNtk );
+int  Abc_FlowRetime_SolveBackwardInit( Abc_Ntk_t * pNtk );
+
+void Abc_FlowRetime_ConstrainInit(  );
+
+/*=== fretTime.c ==========================================================*/
+
+void Abc_FlowRetime_InitTiming( Abc_Ntk_t *pNtk );
+void Abc_FlowRetime_FreeTiming( Abc_Ntk_t *pNtk );
+
+bool Abc_FlowRetime_RefineConstraints( );
 
-extern Abc_Ntk_t *pInitNtk;
-extern int        fSolutionIsDc;
+void Abc_FlowRetime_ConstrainConserv( Abc_Ntk_t * pNtk );
+void Abc_FlowRetime_ConstrainExact( Abc_Obj_t * pObj );
+void Abc_FlowRetime_ConstrainExactAll( Abc_Ntk_t * pNtk );
 
 #endif

src/opt/fret/module.make

 SRC +=    src/opt/fret/fretMain.c \
     src/opt/fret/fretFlow.c \
-        src/opt/fret/fretInit.c
+        src/opt/fret/fretInit.c \
+    src/opt/fret/fretTime.c