Allow retiming to skip some logic.

src/base/wlc/wlcCom.c

@@ -1331,16 +1331,20 @@ usage:
 ******************************************************************************/
 int Abc_CommandRetime( Abc_Frame_t * pAbc, int argc, char ** argv )
 {
-    extern void Wln_NtkRetimeTest( char * pFileName, int fSkipSimple, int fDump, int fVerbose );
+    extern void Wln_NtkRetimeTest( char * pFileName, int fIgnoreIO, int fSkipSimple, int fDump, int fVerbose );
     FILE * pFile;
     char * pFileName = NULL;
+    int fIgnoreIO = 0;
     int fSkipSimple  = 0;
     int c, fDump = 0, fVerbose  = 0;
     Extra_UtilGetoptReset();
-    while ( ( c = Extra_UtilGetopt( argc, argv, "sdvh" ) ) != EOF )
+    while ( ( c = Extra_UtilGetopt( argc, argv, "isdvh" ) ) != EOF )
     {
         switch ( c )
         {
+        case 'i':
+            fIgnoreIO ^= 1;
+            break;
         case 's':
             fSkipSimple ^= 1;
             break;
@@ -1366,7 +1370,7 @@ int Abc_CommandRetime( Abc_Frame_t * pAbc, int argc, char ** argv )
             printf( "Transforming NDR into internal represnetation has failed.\n" );
             return 0;
         }
-        vMoves = Wln_NtkRetime( pNtk, fSkipSimple, fVerbose );
+        vMoves = Wln_NtkRetime( pNtk, fIgnoreIO, fSkipSimple, fVerbose );
         Wln_NtkFree( pNtk );
         ABC_FREE( pAbc->pNdrArray );
         if ( vMoves ) pAbc->pNdrArray = Vec_IntReleaseNewArray( vMoves );
@@ -1389,11 +1393,12 @@ int Abc_CommandRetime( Abc_Frame_t * pAbc, int argc, char ** argv )
         return 0;
     }
     fclose( pFile );
-    Wln_NtkRetimeTest( pFileName, fSkipSimple, fDump, fVerbose );
+    Wln_NtkRetimeTest( pFileName, fIgnoreIO, fSkipSimple, fDump, fVerbose );
     return 0;
 usage:
-    Abc_Print( -2, "usage: %%retime [-sdvh]\n" );
+    Abc_Print( -2, "usage: %%retime [-isdvh]\n" );
     Abc_Print( -2, "\t         performs retiming for the NDR design\n" );
+    Abc_Print( -2, "\t-i     : toggle ignoring delays of IO paths [default = %s]\n", fIgnoreIO? "yes": "no" );
     Abc_Print( -2, "\t-s     : toggle printing simple nodes [default = %s]\n", !fSkipSimple? "yes": "no" );
     Abc_Print( -2, "\t-d     : toggle dumping the network in Verilog [default = %s]\n", fDump? "yes": "no" );
     Abc_Print( -2, "\t-v     : toggle printing verbose information [default = %s]\n", fVerbose? "yes": "no" );

src/base/wln/wln.h

@@ -246,7 +246,7 @@ extern int            Wln_ObjClone( Wln_Ntk_t * pNew, Wln_Ntk_t * p, int iObj );
 extern int            Wln_ObjCreateCo( Wln_Ntk_t * p, int iFanin );
 extern void           Wln_ObjPrint( Wln_Ntk_t * p, int iObj );
 /*=== wlcRetime.c ========================================================*/
-extern Vec_Int_t *    Wln_NtkRetime( Wln_Ntk_t * p, int fSkipSimple, int fVerbose );
+extern Vec_Int_t *    Wln_NtkRetime( Wln_Ntk_t * p, int fIgnoreIO, int fSkipSimple, int fVerbose );
 extern void           Wln_NtkRetimeCreateDelayInfo( Wln_Ntk_t * pNtk );
 /*=== wlcWriteVer.c ========================================================*/
 extern void           Wln_WriteVer( Wln_Ntk_t * p, char * pFileName );

src/base/wln/wlnNdr.c

@@ -314,7 +314,7 @@ void Wln_ReadNdrTest()
     Wln_NtkStaticFanoutTest( pNtk );
     Wln_NtkFree( pNtk );
 }
-void Wln_NtkRetimeTest( char * pFileName, int fSkipSimple, int fDump, int fVerbose )
+void Wln_NtkRetimeTest( char * pFileName, int fIgnoreIO, int fSkipSimple, int fDump, int fVerbose )
 {
     Vec_Int_t * vMoves;
     void * pData = Ndr_Read( pFileName );
@@ -326,7 +326,7 @@ void Wln_NtkRetimeTest( char * pFileName, int fSkipSimple, int fDump, int fVerbo
         return;
     }
     Wln_NtkRetimeCreateDelayInfo( pNtk );
-    vMoves = Wln_NtkRetime( pNtk, fSkipSimple, fVerbose );
+    vMoves = Wln_NtkRetime( pNtk, fIgnoreIO, fSkipSimple, fVerbose );
     //Vec_IntPrint( vMoves );
     Vec_IntFree( vMoves );
     Wln_NtkFree( pNtk );

src/base/wln/wlnRetime.c

@@ -335,6 +335,55 @@ void Wln_RetFindSources( Wln_Ret_t * p )
 
 /**Function*************************************************************
 
+  Synopsis    [Mark paths from PIs to POs.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Wln_RetMarkPaths_rec( Wln_Ntk_t * p, int iObj, int fVerbose )
+{
+    int k, iFanin, fPrev = 1;
+    if ( Wln_ObjIsTravIdPrevious(p, iObj) )
+        return 1;
+    if ( Wln_ObjIsTravIdCurrent(p, iObj) )
+        return 0;
+    if ( Wln_ObjIsCio(p, iObj) || Wln_ObjIsFf(p, iObj) )
+        return 0;
+    Wln_ObjForEachFanin( p, iObj, iFanin, k )
+        fPrev &= Wln_RetMarkPaths_rec( p, iFanin, fVerbose );
+    if ( fPrev )
+    {
+        Wln_ObjSetTravIdPrevious( p, iObj );
+        if ( Vec_IntEntry(&p->vInstIds, iObj) > 0 )
+        {
+            if ( fVerbose )
+                printf( "Updating delay %5d -> %5d : ", Vec_IntEntry(&p->vInstIds, iObj), 1 );
+            if ( fVerbose )
+                Wln_ObjPrint( p, iObj );
+            Vec_IntWriteEntry( &p->vInstIds, iObj, 1 );
+        }
+        return 1;
+    }
+    Wln_ObjSetTravIdCurrent( p, iObj );
+    return 0;
+}
+void Wln_RetMarkPaths( Wln_Ntk_t * p, int fVerbose )
+{
+    int i, iObj;
+    Wln_NtkIncrementTravId( p );
+    Wln_NtkIncrementTravId( p );
+    Wln_NtkForEachPi( p, iObj, i )
+        Wln_ObjSetTravIdPrevious( p, iObj );
+    Wln_NtkForEachPo( p, iObj, i )
+        Wln_RetMarkPaths_rec( p, Wln_ObjFanin0(p, iObj), fVerbose );
+}
+
+/**Function*************************************************************
+
   Synopsis    [Retimability check.]
 
   Description []
@@ -571,7 +620,7 @@ void Wln_NtkRetimeCreateDelayInfo( Wln_Ntk_t * pNtk )
         printf( "Assuming default delays: 10 units for most nodes and 1 unit for bit-slice, concat, and buffers driving COs.\n" );
     }
 }
-Vec_Int_t * Wln_NtkRetime( Wln_Ntk_t * pNtk, int fSkipSimple, int fVerbose )
+Vec_Int_t * Wln_NtkRetime_int( Wln_Ntk_t * pNtk, int fSkipSimple, int fVerbose )
 {
     Wln_Ret_t * p = Wln_RetAlloc( pNtk );
     Vec_Int_t * vSources = &p->vSources;
@@ -666,6 +715,12 @@ Vec_Int_t * Wln_NtkRetime( Wln_Ntk_t * pNtk, int fSkipSimple, int fVerbose )
     }
     return vMoves;
 }
+Vec_Int_t * Wln_NtkRetime( Wln_Ntk_t * pNtk, int fIgnoreIO, int fSkipSimple, int fVerbose )
+{
+    if ( fIgnoreIO )
+        Wln_RetMarkPaths( pNtk, fVerbose );
+    return Wln_NtkRetime_int( pNtk, fSkipSimple, fVerbose );
+}
 
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///