Version abc80205

1 files changed, 303 insertions, 0 deletions

diff --git a/src/opt/mfs/mfsDiv.c b/src/opt/mfs/mfsDiv.c
new file mode 100644
index 00000000..7b156b97
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+++ b/src/opt/mfs/mfsDiv.c
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+/**CFile****************************************************************
+
+  FileName    [mfsDiv.c]
+
+  SystemName  [ABC: Logic synthesis and verification system.]
+
+  PackageName [The good old minimization with complete don't-cares.]
+
+  Synopsis    [Procedures to compute candidate divisors.]
+
+  Author      [Alan Mishchenko]
+  
+  Affiliation [UC Berkeley]
+
+  Date        [Ver. 1.0. Started - June 20, 2005.]
+
+  Revision    [$Id: mfsDiv.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $]
+
+***********************************************************************/
+
+#include "mfsInt.h"
+
+////////////////////////////////////////////////////////////////////////
+///                        DECLARATIONS                              ///
+////////////////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////////////////
+///                     FUNCTION DEFINITIONS                         ///
+////////////////////////////////////////////////////////////////////////
+
+/**Function*************************************************************
+
+  Synopsis    [Marks and collects the TFI cone of the node.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Abc_MfsWinMarkTfi_rec( Abc_Obj_t * pObj, Vec_Ptr_t * vCone )
+{
+    Abc_Obj_t * pFanin;
+    int i;
+    if ( Abc_NodeIsTravIdCurrent(pObj) )
+        return;
+    Abc_NodeSetTravIdCurrent( pObj );
+    if ( Abc_ObjIsCi(pObj) )
+    {
+        Vec_PtrPush( vCone, pObj );
+        return;
+    }
+    assert( Abc_ObjIsNode(pObj) );
+    // visit the fanins of the node
+    Abc_ObjForEachFanin( pObj, pFanin, i )
+        Abc_MfsWinMarkTfi_rec( pFanin, vCone );
+    Vec_PtrPush( vCone, pObj );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Marks and collects the TFI cone of the node.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Ptr_t * Abc_MfsWinMarkTfi( Abc_Obj_t * pNode )
+{
+    Vec_Ptr_t * vCone;
+    vCone = Vec_PtrAlloc( 100 );
+    Abc_MfsWinMarkTfi_rec( pNode, vCone );
+    return vCone;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Marks the TFO of the collected nodes up to the given level.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+void Abc_MfsWinSweepLeafTfo_rec( Abc_Obj_t * pObj, int nLevelLimit )
+{
+    Abc_Obj_t * pFanout;
+    int i;
+    if ( Abc_ObjIsCo(pObj) || (int)pObj->Level > nLevelLimit )
+        return;
+    if ( Abc_NodeIsTravIdCurrent(pObj) )
+        return;
+    Abc_NodeSetTravIdCurrent( pObj );
+    Abc_ObjForEachFanout( pObj, pFanout, i )
+        Abc_MfsWinSweepLeafTfo_rec( pFanout, nLevelLimit );
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Dereferences the node's MFFC.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_MfsNodeDeref_rec( Abc_Obj_t * pNode )
+{
+    Abc_Obj_t * pFanin;
+    int i, Counter = 1;
+    if ( Abc_ObjIsCi(pNode) )
+        return 0;
+    Abc_NodeSetTravIdCurrent( pNode );
+    Abc_ObjForEachFanin( pNode, pFanin, i )
+    {
+        assert( pFanin->vFanouts.nSize > 0 );
+        if ( --pFanin->vFanouts.nSize == 0 )
+            Counter += Abc_MfsNodeDeref_rec( pFanin );
+    }
+    return Counter;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [References the node's MFFC.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_MfsNodeRef_rec( Abc_Obj_t * pNode )
+{
+    Abc_Obj_t * pFanin;
+    int i, Counter = 1;
+    if ( Abc_ObjIsCi(pNode) )
+        return 0;
+    Abc_ObjForEachFanin( pNode, pFanin, i )
+    {
+        if ( pFanin->vFanouts.nSize++ == 0 )
+            Counter += Abc_MfsNodeRef_rec( pFanin );
+    }
+    return Counter;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Labels MFFC of the node with the current trav ID.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+int Abc_MfsWinVisitMffc( Abc_Obj_t * pNode )
+{
+    int Count1, Count2;
+    assert( Abc_ObjIsNode(pNode) );
+    // dereference the node (mark with the current trav ID)
+    Count1 = Abc_MfsNodeDeref_rec( pNode );
+    // reference it back
+    Count2 = Abc_MfsNodeRef_rec( pNode );
+    assert( Count1 == Count2 );
+    return Count1;
+}
+
+/**Function*************************************************************
+
+  Synopsis    [Computes divisors and add them to nodes in the window.]
+
+  Description []
+               
+  SideEffects []
+
+  SeeAlso     []
+
+***********************************************************************/
+Vec_Ptr_t * Abc_MfsComputeDivisors( Mfs_Man_t * p, Abc_Obj_t * pNode, int nLevDivMax )
+{
+    Vec_Ptr_t * vCone, * vDivs;
+    Abc_Obj_t * pObj, * pFanout, * pFanin;
+    int k, f, m;
+    int nDivsPlus = 0, nTrueSupp;
+    assert( p->vDivs == NULL );
+
+    // mark the TFI with the current trav ID
+    Abc_NtkIncrementTravId( pNode->pNtk );
+    vCone = Abc_MfsWinMarkTfi( pNode );
+
+    // count the number of PIs
+    nTrueSupp = 0;
+    Vec_PtrForEachEntry( vCone, pObj, k )
+        nTrueSupp += Abc_ObjIsCi(pObj);
+//    printf( "%d(%d) ", Vec_PtrSize(p->vSupp), m );
+
+    // mark with the current trav ID those nodes that should not be divisors:
+    // (1) the node and its TFO
+    // (2) the MFFC of the node
+    // (3) the node's fanins (these are treated as a special case)
+    Abc_NtkIncrementTravId( pNode->pNtk );
+    Abc_MfsWinSweepLeafTfo_rec( pNode, nLevDivMax );
+    Abc_MfsWinVisitMffc( pNode );
+    Abc_ObjForEachFanin( pNode, pObj, k )
+        Abc_NodeSetTravIdCurrent( pObj );
+
+    // at this point the nodes are marked with two trav IDs:
+    // nodes to be collected as divisors are marked with previous trav ID
+    // nodes to be avoided as divisors are marked with current trav ID
+
+    // start collecting the divisors
+    vDivs = Vec_PtrAlloc( p->pPars->nDivMax );
+    Vec_PtrForEachEntry( vCone, pObj, k )
+    {
+        if ( !Abc_NodeIsTravIdPrevious(pObj) )
+            continue;
+        if ( (int)pObj->Level > nLevDivMax )
+            continue;
+        Vec_PtrPush( vDivs, pObj );
+        if ( Vec_PtrSize(vDivs) >= p->pPars->nDivMax )
+            break;
+    }
+    Vec_PtrFree( vCone );
+
+    // explore the fanouts of already collected divisors
+    if ( Vec_PtrSize(vDivs) < p->pPars->nDivMax )
+    Vec_PtrForEachEntry( vDivs, pObj, k )
+    {
+        // consider fanouts of this node
+        Abc_ObjForEachFanout( pObj, pFanout, f )
+        {
+            // stop if there are too many fanouts
+            if ( f > 20 )
+                break;
+            // skip nodes that are already added
+            if ( Abc_NodeIsTravIdPrevious(pFanout) )
+                continue;
+            // skip nodes in the TFO or in the MFFC of node
+            if ( Abc_NodeIsTravIdCurrent(pFanout) )
+                continue;
+            // skip COs
+            if ( !Abc_ObjIsNode(pFanout) ) 
+                continue;
+            // skip nodes with large level
+            if ( (int)pFanout->Level >= nLevDivMax )
+                continue;
+            // skip nodes whose fanins are not divisors
+            Abc_ObjForEachFanin( pFanout, pFanin, m )
+                if ( !Abc_NodeIsTravIdPrevious(pFanin) )
+                    break;
+            if ( m < Abc_ObjFaninNum(pFanout) )
+                continue;
+            // make sure this divisor in not among the nodes
+//            Vec_PtrForEachEntry( p->vNodes, pFanin, m )
+//                assert( pFanout != pFanin );
+            // add the node to the divisors
+            Vec_PtrPush( vDivs, pFanout );
+//            Vec_PtrPush( p->vNodes, pFanout );
+            Vec_PtrPushUnique( p->vNodes, pFanout );
+            Abc_NodeSetTravIdPrevious( pFanout );
+            nDivsPlus++;
+            if ( Vec_PtrSize(vDivs) >= p->pPars->nDivMax )
+                break;
+        }
+        if ( Vec_PtrSize(vDivs) >= p->pPars->nDivMax )
+            break;
+    }
+
+    // sort the divisors by level in the increasing order
+    Vec_PtrSort( vDivs, Abc_NodeCompareLevelsIncrease );
+
+    // add the fanins of the node
+    Abc_ObjForEachFanin( pNode, pFanin, k )
+        Vec_PtrPush( vDivs, pFanin );
+
+/*
+    printf( "Node level = %d.  ", Abc_ObjLevel(p->pNode) );
+    Vec_PtrForEachEntryStart( vDivs, pObj, k, Vec_PtrSize(vDivs)-p->nDivsPlus )
+        printf( "%d ", Abc_ObjLevel(pObj) );
+    printf( "\n" );
+*/
+//printf( "%d ", p->nDivsPlus );
+//    printf( "(%d+%d)(%d+%d+%d) ", Vec_PtrSize(p->vSupp), Vec_PtrSize(p->vNodes), 
+//        nTrueSupp, Vec_PtrSize(vDivs)-nTrueSupp-nDivsPlus, nDivsPlus );
+    return vDivs;
+}
+
+////////////////////////////////////////////////////////////////////////
+///                       END OF FILE                                ///
+////////////////////////////////////////////////////////////////////////
+
+