Adding new command &sopb for resource-aware SOP balancing.

7 files changed, 404 insertions, 35 deletions

diff --git a/src/aig/gia/gia.h b/src/aig/gia/gia.h
index 6fc30367..b641da7f 100644
--- a/src/aig/gia/gia.h
+++ b/src/aig/gia/gia.h
@@ -966,13 +966,15 @@ static inline int         Gia_ObjLutIsMux( Gia_Man_t * p, int Id )          { re
     for ( i = Vec_IntSize(p->vCis) - 1; (i >= 0) && ((pObj) = Gia_ManCi(p, i)); i-- )
 #define Gia_ManForEachCo( p, pObj, i )                                  \
     for ( i = 0; (i < Vec_IntSize(p->vCos)) && ((pObj) = Gia_ManCo(p, i)); i++ )
+#define Gia_ManForEachCoVec( vVec, p, pObj, i )                         \
+    for ( i = 0; (i < Vec_IntSize(vVec)) && ((pObj) = Gia_ManCo(p, Vec_IntEntry(vVec,i))); i++ )
 #define Gia_ManForEachCoId( p, Id, i )                                  \
     for ( i = 0; (i < Vec_IntSize(p->vCos)) && ((Id) = Gia_ObjId(p, Gia_ManCo(p, i))); i++ )
 #define Gia_ManForEachCoReverse( p, pObj, i )                           \
     for ( i = Vec_IntSize(p->vCos) - 1; (i >= 0) && ((pObj) = Gia_ManCo(p, i)); i-- )
 #define Gia_ManForEachCoDriver( p, pObj, i )                            \
     for ( i = 0; (i < Vec_IntSize(p->vCos)) && ((pObj) = Gia_ObjFanin0(Gia_ManCo(p, i))); i++ )
-#define Gia_ManForEachCoDriverId( p, DriverId, i )                            \
+#define Gia_ManForEachCoDriverId( p, DriverId, i )                      \
     for ( i = 0; (i < Vec_IntSize(p->vCos)) && (((DriverId) = Gia_ObjFaninId0p(p, Gia_ManCo(p, i))), 1); i++ )
 #define Gia_ManForEachPi( p, pObj, i )                                  \
     for ( i = 0; (i < Gia_ManPiNum(p)) && ((pObj) = Gia_ManCi(p, i)); i++ )
@@ -1165,6 +1167,7 @@ extern void                Gia_ManSetIfParsDefault( void * pIfPars );
 extern void                Gia_ManMappingVerify( Gia_Man_t * p );
 extern void                Gia_ManTransferMapping( Gia_Man_t * pGia, Gia_Man_t * p );
 extern Gia_Man_t *         Gia_ManPerformMapping( Gia_Man_t * p, void * pIfPars, int fNormalized );
+extern Gia_Man_t *         Gia_ManPerformSopBalance( Gia_Man_t * p, int nCutNum, int nRelaxRatio, int fVerbose );
 /*=== giaJf.c ===========================================================*/
 extern void                Jf_ManSetDefaultPars( Jf_Par_t * pPars );
 extern Gia_Man_t *         Jf_ManPerformMapping( Gia_Man_t * pGia, Jf_Par_t * pPars );
@@ -1237,6 +1240,8 @@ extern Gia_Man_t *         Gia_ManSeqStructSweep( Gia_Man_t * p, int fConst, int
 /*=== giaShrink.c ===========================================================*/
 extern Gia_Man_t *         Gia_ManMapShrink4( Gia_Man_t * p, int fKeepLevel, int fVerbose );
 extern Gia_Man_t *         Gia_ManMapShrink6( Gia_Man_t * p, int nFanoutMax, int fKeepLevel, int fVerbose );
+/*=== giaSopb.c ============================================================*/
+extern Gia_Man_t *         Gia_ManPerformSopBalanceWin( Gia_Man_t * p, int LevelMax, int nLevelRatio, int nCutNum, int nRelaxRatio, int fVerbose );
 /*=== giaSort.c ============================================================*/
 extern int *               Gia_SortFloats( float * pArray, int * pPerm, int nSize );
 /*=== giaSim.c ============================================================*/
diff --git a/src/aig/gia/giaIf.c b/src/aig/gia/giaIf.c
index 20204798..a3ebf305 100644
--- a/src/aig/gia/giaIf.c
+++ b/src/aig/gia/giaIf.c
@@ -1732,6 +1732,32 @@ Gia_Man_t * Gia_ManPerformMapping( Gia_Man_t * p, void * pp, int fNormalized )
     Gia_ManStop( p );
     return pNew;
 }
+Gia_Man_t * Gia_ManPerformSopBalance( Gia_Man_t * p, int nCutNum, int nRelaxRatio, int fVerbose )
+{
+    Gia_Man_t * pNew;
+    If_Man_t * pIfMan;
+    If_Par_t Pars, * pPars = &Pars;
+    If_ManSetDefaultPars( pPars );
+    pPars->nCutsMax    = nCutNum;
+    pPars->nRelaxRatio = nRelaxRatio;
+    pPars->fVerbose    = fVerbose;
+    pPars->nLutSize    = 6;
+    pPars->fDelayOpt   = 1;
+    pPars->fCutMin     = 1;
+    pPars->fTruth      = 1;
+    pPars->fExpRed     = 0;
+    // perform mapping
+    pIfMan = Gia_ManToIf( p, pPars );
+    If_ManPerformMapping( pIfMan );
+    pNew = Gia_ManFromIfAig( pIfMan );
+    If_ManStop( pIfMan );
+    // transfer name
+    assert( pNew->pName == NULL );
+    pNew->pName = Abc_UtilStrsav( p->pName );
+    pNew->pSpec = Abc_UtilStrsav( p->pSpec );
+    Gia_ManSetRegNum( pNew, Gia_ManRegNum(p) );
+    return pNew;
+}
 
 /**Function*************************************************************
 
diff --git a/src/aig/gia/giaSopb.c b/src/aig/gia/giaSopb.c
new file mode 100644
index 00000000..28e01c8c
--- /dev/null
+++ b/src/aig/gia/giaSopb.c
@@ -0,0 +1,230 @@
+/**CFile****************************************************************
+
+  FileName    [giaSopb.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [Scalable AIG package.]
+
+  Synopsis    [SOP balancing for a window.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: giaSopb.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "gia.h"
+
+ABC_NAMESPACE_IMPL_START
+
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Gia_ManHighlight_rec( Gia_Man_t * p, int iObj )
+{
+    Gia_Obj_t * pObj;
+    if ( Gia_ObjIsTravIdCurrentId(p, iObj) )
+        return;
+    Gia_ObjSetTravIdCurrentId(p, iObj);
+    pObj = Gia_ManObj( p, iObj );
+    if ( Gia_ObjIsAnd(pObj) )
+        Gia_ManHighlight_rec( p, Gia_ObjFaninId0(pObj, iObj) );
+    if ( Gia_ObjIsAnd(pObj) )
+        Gia_ManHighlight_rec( p, Gia_ObjFaninId1(pObj, iObj) );
+}
+void Gia_ManPrepareWin( Gia_Man_t * p, Vec_Int_t * vOuts, Vec_Int_t ** pvPis, Vec_Int_t ** pvPos, Vec_Int_t ** pvAnds )
+{
+    Gia_Obj_t * pObj;
+    int i;
+    // mark the section
+    Gia_ManIncrementTravId( p );
+    Gia_ManForEachCoVec( vOuts, p, pObj, i )
+        Gia_ManHighlight_rec( p, Gia_ObjFaninId0p(p, pObj) );
+    // mark fanins of the outside area
+    Gia_ManCleanMark0( p );
+    Gia_ManForEachObj1( p, pObj, i )
+    {
+        if ( Gia_ObjIsCi(pObj) )
+            continue;
+        if ( Gia_ObjIsAnd(pObj) && !Gia_ObjIsTravIdCurrentId(p, i) )
+            continue;
+        Gia_ObjFanin0(pObj)->fMark0 = 1;
+        if ( Gia_ObjIsAnd(pObj) )
+            Gia_ObjFanin1(pObj)->fMark0 = 1;
+    }
+    // collect pointed nodes
+    *pvPis  = Vec_IntAlloc( 1000 );
+    *pvPos  = Vec_IntAlloc( 1000 );
+    *pvAnds = Vec_IntAlloc( 1000 );
+    Gia_ManForEachObj1( p, pObj, i )
+    {
+        if ( !Gia_ObjIsTravIdCurrentId(p, i) )
+            continue;
+        if ( Gia_ObjIsCi(pObj) )
+            Vec_IntPush( *pvPis, i );
+        else if ( pObj->fMark0 )
+            Vec_IntPush( *pvPos, i );
+        if ( Gia_ObjIsAnd(pObj) )
+            Vec_IntPush( *pvAnds, i );
+    }
+    Gia_ManCleanMark0( p );
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_ManExtractWin( Gia_Man_t * p, Vec_Int_t * vOuts )
+{
+    Vec_Int_t * vPis, * vPos, * vAnds;
+    Gia_Man_t * pNew;
+    Gia_Obj_t * pObj;
+    int i;
+    Gia_ManPrepareWin( p, vOuts, &vPis, &vPos, &vAnds );
+    // create AIG
+    pNew = Gia_ManStart( Vec_IntSize(vPis) + Vec_IntSize(vPos) + Vec_IntSize(vAnds) + 1 );
+    pNew->pName = Abc_UtilStrsav( p->pName );
+    Gia_ManConst0(p)->Value = 0;
+    Gia_ManForEachObjVec( vPis, p, pObj, i )
+        pObj->Value = Gia_ManAppendCi( pNew );
+    Gia_ManForEachObjVec( vAnds, p, pObj, i )
+        pObj->Value = Gia_ManAppendAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachObjVec( vPos, p, pObj, i )
+        Gia_ManAppendCo( pNew, pObj->Value );
+    Vec_IntFree( vPis );
+    Vec_IntFree( vPos );
+    Vec_IntFree( vAnds );
+    return pNew;
+}
+Gia_Man_t * Gia_ManInsertWin( Gia_Man_t * p, Vec_Int_t * vOuts, Gia_Man_t * pWin )
+{
+    Vec_Int_t * vPos, * vPis, * vAnds;
+    Gia_Man_t * pNew, * pTemp;
+    Gia_Obj_t * pObj;
+    int i;
+    Gia_ManPrepareWin( p, vOuts, &vPis, &vPos, &vAnds );
+    // create AIG
+    pNew = Gia_ManStart( Gia_ManObjNum(p) - Vec_IntSize(vAnds) + Gia_ManAndNum(pWin) );
+    pNew->pName = Abc_UtilStrsav( p->pName );
+    pNew->pSpec = Abc_UtilStrsav( p->pSpec );
+    // inputs
+    Gia_ManConst0(p)->Value = 0;
+    Gia_ManForEachCi( p, pObj, i )
+        pObj->Value = Gia_ManAppendCi( pNew );
+    Gia_ManConst0(pWin)->Value = 0;
+    Gia_ManForEachCi( pWin, pObj, i )
+        pObj->Value = Gia_ManObj(p, Vec_IntEntry(vPis, i))->Value;
+    // internal nodes
+    Gia_ManHashAlloc( pNew );
+    Gia_ManForEachAnd( pWin, pObj, i )
+        pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachCo( pWin, pObj, i )
+        Gia_ManObj( p, Vec_IntEntry(vPos, i) )->Value = Gia_ObjFanin0Copy(pObj);
+    Gia_ManForEachAnd( p, pObj, i )
+        if ( !Gia_ObjIsTravIdCurrentId(p, i) )
+            pObj->Value = Gia_ManHashAnd( pNew, Gia_ObjFanin0Copy(pObj), Gia_ObjFanin1Copy(pObj) );
+    Gia_ManForEachCo( p, pObj, i )
+        Gia_ManAppendCo( pNew, Gia_ObjFanin0Copy(pObj) );
+    Gia_ManHashStop( pNew );
+    // cleanup
+    Vec_IntFree( vPis );
+    Vec_IntFree( vPos );
+    Vec_IntFree( vAnds );
+    pNew = Gia_ManCleanup( pTemp = pNew );
+    Gia_ManStop( pTemp );
+    return pNew;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Int_t * Gia_ManFindLatest( Gia_Man_t * p, int LevelMax )
+{
+    Vec_Int_t * vOuts;
+    Gia_Obj_t * pObj;
+    int i;
+    vOuts = Vec_IntAlloc( 1000 );
+    Gia_ManForEachCo( p, pObj, i )
+        if ( Gia_ObjLevel(p, pObj) > LevelMax )
+            Vec_IntPush( vOuts, i );
+    return vOuts;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Gia_Man_t * Gia_ManPerformSopBalanceWin( Gia_Man_t * p, int LevelMax, int nLevelRatio, int nCutNum, int nRelaxRatio, int fVerbose )
+{
+    Vec_Int_t * vOuts;
+    Gia_Man_t * pNew, * pWin, * pWinNew;
+    int nLevels = Gia_ManLevelNum( p );
+    if ( nLevelRatio )
+        LevelMax = (int)((1.0 - 0.01 * nLevelRatio) * nLevels);
+//printf( "Using LevelMax = %d.\n", LevelMax );
+    vOuts = Gia_ManFindLatest( p, LevelMax );
+    if ( Vec_IntSize(vOuts) == 0 )
+    {
+        Vec_IntFree( vOuts );
+        return Gia_ManDup( p );
+    }
+    pWin = Gia_ManExtractWin( p, vOuts );
+    pWinNew = Gia_ManPerformSopBalance( pWin, nCutNum, nRelaxRatio, fVerbose );
+    Gia_ManStop( pWin );
+    pNew = Gia_ManInsertWin( p, vOuts, pWinNew );
+    Gia_ManStop( pWinNew );
+    Vec_IntFree( vOuts );
+    return pNew;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+
+ABC_NAMESPACE_IMPL_END
+
diff --git a/src/aig/gia/module.make b/src/aig/gia/module.make
index 471b750a..a8ebc836 100644
--- a/src/aig/gia/module.make
+++ b/src/aig/gia/module.make
@@ -51,6 +51,7 @@ SRC +=    src/aig/gia/giaAig.c \
     src/aig/gia/giaShrink7.c \
     src/aig/gia/giaSim.c \
     src/aig/gia/giaSim2.c \
+    src/aig/gia/giaSopb.c \
     src/aig/gia/giaSort.c \
     src/aig/gia/giaSpeedup.c \
     src/aig/gia/giaStg.c \
diff --git a/src/base/abci/abc.c b/src/base/abci/abc.c
index 08069f98..6a85774f 100644
--- a/src/base/abci/abc.c
+++ b/src/base/abci/abc.c
@@ -377,6 +377,7 @@ static int Abc_CommandAbc9Verify             ( Abc_Frame_t * pAbc, int argc, cha
 static int Abc_CommandAbc9Sweep              ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Force              ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Embed              ( Abc_Frame_t * pAbc, int argc, char ** argv );
+static int Abc_CommandAbc9Sopb               ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9If                 ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9Iff                ( Abc_Frame_t * pAbc, int argc, char ** argv );
 static int Abc_CommandAbc9If2                ( Abc_Frame_t * pAbc, int argc, char ** argv );
@@ -957,6 +958,7 @@ void Abc_Init( Abc_Frame_t * pAbc )
     Cmd_CommandAdd( pAbc, "ABC9",         "&sweep",        Abc_CommandAbc9Sweep,        0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&force",        Abc_CommandAbc9Force,        0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&embed",        Abc_CommandAbc9Embed,        0 );
+    Cmd_CommandAdd( pAbc, "ABC9",         "&sopb",         Abc_CommandAbc9Sopb,         0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&if",           Abc_CommandAbc9If,           0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&iff",          Abc_CommandAbc9Iff,          0 );
     Cmd_CommandAdd( pAbc, "ABC9",         "&if2",          Abc_CommandAbc9If2,          0 );
@@ -14932,44 +14934,14 @@ usage:
 ***********************************************************************/
 int Abc_CommandIf( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
-    char Buffer[100];
-    char LutSize[100];
+    extern Abc_Ntk_t * Abc_NtkIf( Abc_Ntk_t * pNtk, If_Par_t * pPars );
+    char Buffer[100], LutSize[100];
     Abc_Ntk_t * pNtk, * pNtkRes;
     If_Par_t Pars, * pPars = &Pars;
     int c;
-    extern Abc_Ntk_t * Abc_NtkIf( Abc_Ntk_t * pNtk, If_Par_t * pPars );
-
     pNtk = Abc_FrameReadNtk(pAbc);
-    // set defaults
-    memset( pPars, 0, sizeof(If_Par_t) );
-    // user-controlable paramters
-    pPars->nLutSize    = -1;
-    pPars->nCutsMax    =  8;
-    pPars->nFlowIters  =  1;
-    pPars->nAreaIters  =  2;
-    pPars->DelayTarget = -1;
-    pPars->Epsilon     =  (float)0.005;
-    pPars->fPreprocess =  1;
-    pPars->fArea       =  0;
-    pPars->fFancy      =  0;
-    pPars->fExpRed     =  1;
-    pPars->fLatchPaths =  0;
-    pPars->fEdge       =  1;
-    pPars->fPower      =  0;
-    pPars->fCutMin     =  0;
-    pPars->fBidec      =  0;
-    pPars->fVerbose    =  0;
-    pPars->pLutStruct  =  NULL;
-    // internal parameters
-    pPars->fTruth      =  0;
-    pPars->nLatchesCi  =  pNtk? Abc_NtkLatchNum(pNtk) : 0;
-    pPars->nLatchesCo  =  pNtk? Abc_NtkLatchNum(pNtk) : 0;
-    pPars->fLiftLeaves =  0;
-    pPars->pLutLib     =  (If_LibLut_t *)Abc_FrameReadLibLut();
-    pPars->pTimesArr   =  NULL;
-    pPars->pTimesArr   =  NULL;
-    pPars->pFuncCost   =  NULL;
-
+    If_ManSetDefaultPars( pPars );
+    pPars->pLutLib = (If_LibLut_t *)Abc_FrameReadLibLut();
     Extra_UtilGetoptReset();
     while ( ( c = Extra_UtilGetopt( argc, argv, "KCFAGNDEWSTqaflepmrsdbgxyojiktncvh" ) ) != EOF )
     {
@@ -30059,6 +30031,107 @@ usage:
   SeeAlso     []
 
 ***********************************************************************/
+int Abc_CommandAbc9Sopb( Abc_Frame_t * pAbc, int argc, char ** argv )
+{
+    Gia_Man_t * pTemp;
+    int nLevelMax   = 0;
+    int nLevelRatio = 0;
+    int nCutNum     = 8;
+    int nRelaxRatio = 0;
+    int c, fVerbose = 0;
+    Extra_UtilGetoptReset();
+    while ( ( c = Extra_UtilGetopt( argc, argv, "LQCRvh" ) ) != EOF )
+    {
+        switch ( c )
+        {
+        case 'L':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-L\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nLevelMax = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nLevelMax < 0 )
+                goto usage;
+            break;
+        case 'Q':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-Q\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nLevelRatio = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nLevelRatio < 0 )
+                goto usage;
+            break;
+        case 'C':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-C\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nCutNum = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nCutNum < 0 )
+                goto usage;
+            break;
+        case 'R':
+            if ( globalUtilOptind >= argc )
+            {
+                Abc_Print( -1, "Command line switch \"-R\" should be followed by an integer.\n" );
+                goto usage;
+            }
+            nRelaxRatio = atoi(argv[globalUtilOptind]);
+            globalUtilOptind++;
+            if ( nRelaxRatio < 0 )
+                goto usage;
+            break;
+        case 'v':
+            fVerbose ^= 1;
+            break;
+        case 'h':
+            goto usage;
+        default:
+            goto usage;
+        }
+    }
+    if ( pAbc->pGia == NULL )
+    {
+        Abc_Print( -1, "Abc_CommandAbc9Sopb(): There is no AIG.\n" );
+        return 1;
+    }
+    if ( nLevelMax || nLevelRatio )
+        pTemp = Gia_ManPerformSopBalanceWin( pAbc->pGia, nLevelMax, nLevelRatio, nCutNum, nRelaxRatio, fVerbose );
+    else
+        pTemp = Gia_ManPerformSopBalance( pAbc->pGia, nCutNum, nRelaxRatio, fVerbose );
+    Abc_FrameUpdateGia( pAbc, pTemp );
+    return 0;
+
+usage:
+    Abc_Print( -2, "usage: &sopb [-LQCR num] [-vh]\n" );
+    Abc_Print( -2, "\t         performs SOP balancing\n" );
+    Abc_Print( -2, "\t-L num : optimize paths above this level [default = %d]\n", nLevelMax );
+    Abc_Print( -2, "\t-Q num : optimize paths falling into this window [default = %d]\n", nLevelRatio );
+    Abc_Print( -2, "\t-C num : the number of cuts at a node [default = %d]\n", nCutNum );
+    Abc_Print( -2, "\t-R num : the delay relaxation ratio (num >= 0) [default = %d]\n", nRelaxRatio );
+    Abc_Print( -2, "\t-v     : toggle printing verbose information [default = %s]\n", fVerbose? "yes": "no" );
+    Abc_Print( -2, "\t-h     : print the command usage\n");
+    return 1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
 int Abc_CommandAbc9If( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
     char Buffer[200];
diff --git a/src/map/if/if.h b/src/map/if/if.h
index a2312667..5e0dd1b7 100644
--- a/src/map/if/if.h
+++ b/src/map/if/if.h
@@ -480,6 +480,7 @@ static inline float      If_CutLutDelay( If_LibLut_t * p, int Size, int iPin )
 ////////////////////////////////////////////////////////////////////////
 
 /*=== ifCore.c ===========================================================*/
+extern void            If_ManSetDefaultPars( If_Par_t * pPars );
 extern int             If_ManPerformMapping( If_Man_t * p );
 extern int             If_ManPerformMappingComb( If_Man_t * p );
 extern void            If_ManComputeSwitching( If_Man_t * p );
diff --git a/src/map/if/ifCore.c b/src/map/if/ifCore.c
index 1f2d2ae3..b7eb7bc0 100644
--- a/src/map/if/ifCore.c
+++ b/src/map/if/ifCore.c
@@ -44,6 +44,39 @@ extern abctime s_MappingTime;
   SeeAlso     []
 
 ***********************************************************************/
+void If_ManSetDefaultPars( If_Par_t * pPars )
+{
+    memset( pPars, 0, sizeof(If_Par_t) );
+    pPars->nLutSize    = -1;
+    pPars->nCutsMax    =  8;
+    pPars->nFlowIters  =  1;
+    pPars->nAreaIters  =  2;
+    pPars->DelayTarget = -1;
+    pPars->Epsilon     =  (float)0.005;
+    pPars->fPreprocess =  1;
+    pPars->fArea       =  0;
+    pPars->fFancy      =  0;
+    pPars->fExpRed     =  1;
+    pPars->fLatchPaths =  0;
+    pPars->fEdge       =  1;
+    pPars->fPower      =  0;
+    pPars->fCutMin     =  0;
+    pPars->fBidec      =  0;
+    pPars->fVerbose    =  0;
+}
+
+
+/**Function*************************************************************
+
+  Synopsis    []
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
 int If_ManPerformMapping( If_Man_t * p )
 {
     p->pPars->fAreaOnly = p->pPars->fArea; // temporary