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/**CFile****************************************************************
FileName [mapperRefs.c]
PackageName [MVSIS 1.3: Multi-valued logic synthesis system.]
Synopsis [Generic technology mapping engine.]
Author [MVSIS Group]
Affiliation [UC Berkeley]
Date [Ver. 2.0. Started - June 1, 2004.]
Revision [$Id: mapperRefs.h,v 1.0 2003/09/08 00:00:00 alanmi Exp $]
***********************************************************************/
#include "mapperInt.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
static int Map_NodeIncRefPhaseAct( Map_Node_t * pNode, int fPhase );
static int Map_NodeDecRefPhaseAct( Map_Node_t * pNode, int fPhase );
static float Map_CutRefDeref( Map_Cut_t * pCut, int fPhase, int fReference );
static void Map_MappingSetRefs_rec( Map_Man_t * pMan, Map_Node_t * pNode, Map_Node_t ** ppStore );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Reads the actual reference counter of a phase.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Map_NodeReadRefPhaseAct( Map_Node_t * pNode, int fPhase )
{
assert( !Map_IsComplement(pNode) );
if ( pNode->pCutBest[0] && pNode->pCutBest[1] ) // both assigned
return pNode->nRefAct[fPhase];
assert( pNode->pCutBest[0] || pNode->pCutBest[1] ); // at least one assigned
return pNode->nRefAct[2];
}
/**Function*************************************************************
Synopsis [Reads the estimated reference counter of a phase.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float Map_NodeReadRefPhaseEst( Map_Node_t * pNode, int fPhase )
{
assert( !Map_IsComplement(pNode) );
if ( pNode->pCutBest[0] && pNode->pCutBest[1] ) // both assigned
return pNode->nRefEst[fPhase];
assert( pNode->pCutBest[0] || pNode->pCutBest[1] ); // at least one assigned
// return pNode->nRefEst[0] + pNode->nRefEst[1];
return pNode->nRefEst[2];
}
/**Function*************************************************************
Synopsis [Increments the actual reference counter of a phase.]
Description [Returns the old reference counter.]
SideEffects []
SeeAlso []
***********************************************************************/
int Map_NodeIncRefPhaseAct( Map_Node_t * pNode, int fPhase )
{
assert( !Map_IsComplement(pNode) );
if ( pNode->pCutBest[0] && pNode->pCutBest[1] ) // both assigned
return pNode->nRefAct[fPhase]++;
assert( pNode->pCutBest[0] || pNode->pCutBest[1] ); // at least one assigned
return pNode->nRefAct[2]++;
}
/**Function*************************************************************
Synopsis [Decrements the actual reference counter of a phase.]
Description [Returns the new reference counter.]
SideEffects []
SeeAlso []
***********************************************************************/
int Map_NodeDecRefPhaseAct( Map_Node_t * pNode, int fPhase )
{
assert( !Map_IsComplement(pNode) );
if ( pNode->pCutBest[0] && pNode->pCutBest[1] ) // both assigned
return --pNode->nRefAct[fPhase];
assert( pNode->pCutBest[0] || pNode->pCutBest[1] ); // at least one assigned
return --pNode->nRefAct[2];
}
/**Function*************************************************************
Synopsis [Sets the estimated reference counter for the PIs.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Map_MappingEstimateRefsInit( Map_Man_t * p )
{
Map_Node_t * pNode;
int i;
for ( i = 0; i < p->vAnds->nSize; i++ )
{
pNode = p->vAnds->pArray[i];
// pNode->nRefEst[0] = pNode->nRefEst[1] = ((float)pNode->nRefs)*(float)2.0;
pNode->nRefEst[0] = pNode->nRefEst[1] = pNode->nRefEst[2] = ((float)pNode->nRefs);
}
}
/**Function*************************************************************
Synopsis [Sets the estimated reference counter.]
Description [When this procedure is called for the first time,
the reference counter is estimated from the AIG. Otherwise, it is
a linear combination of reference counters in the last two iterations.]
SideEffects []
SeeAlso []
***********************************************************************/
void Map_MappingEstimateRefs( Map_Man_t * p )
{
Map_Node_t * pNode;
int i;
for ( i = 0; i < p->vAnds->nSize; i++ )
{
pNode = p->vAnds->pArray[i];
// pNode->nRefEst[0] = (float)((2.0 * pNode->nRefEst[0] + 1.0 * pNode->nRefAct[0]) / 3.0);
// pNode->nRefEst[1] = (float)((2.0 * pNode->nRefEst[1] + 1.0 * pNode->nRefAct[1]) / 3.0);
// pNode->nRefEst[2] = (float)((2.0 * pNode->nRefEst[2] + 1.0 * pNode->nRefAct[2]) / 3.0);
pNode->nRefEst[0] = (float)((3.0 * pNode->nRefEst[0] + 1.0 * pNode->nRefAct[0]) / 4.0);
pNode->nRefEst[1] = (float)((3.0 * pNode->nRefEst[1] + 1.0 * pNode->nRefAct[1]) / 4.0);
pNode->nRefEst[2] = (float)((3.0 * pNode->nRefEst[2] + 1.0 * pNode->nRefAct[2]) / 4.0);
}
}
/**function*************************************************************
synopsis [Computes the area flow of the cut.]
description [Computes the area flow of the cut if it is implemented using
the best supergate with the best phase.]
sideeffects []
seealso []
***********************************************************************/
float Map_CutGetAreaFlow( Map_Cut_t * pCut, int fPhase )
{
Map_Match_t * pM = pCut->M + fPhase;
Map_Super_t * pSuper = pM->pSuperBest;
unsigned uPhaseTot = pM->uPhaseBest;
Map_Cut_t * pCutFanin;
float aFlowRes, aFlowFanin, nRefs;
int i, fPinPhasePos;
// start the resulting area flow
aFlowRes = pSuper->Area;
// iterate through the leaves
for ( i = 0; i < pCut->nLeaves; i++ )
{
// get the phase of this fanin
fPinPhasePos = ((uPhaseTot & (1 << i)) == 0);
// get the cut implementing this phase of the fanin
pCutFanin = pCut->ppLeaves[i]->pCutBest[fPinPhasePos];
// if the cut is not available, we have to use the opposite phase
if ( pCutFanin == NULL )
{
fPinPhasePos = !fPinPhasePos;
pCutFanin = pCut->ppLeaves[i]->pCutBest[fPinPhasePos];
}
aFlowFanin = pCutFanin->M[fPinPhasePos].AreaFlow; // ignores the area of the interter
// get the fanout count of the cut in the given phase
nRefs = Map_NodeReadRefPhaseEst( pCut->ppLeaves[i], fPinPhasePos );
// if the node does no fanout, assume fanout count equal to 1
if ( nRefs == (float)0.0 )
nRefs = (float)1.0;
// add the area flow due to the fanin
aFlowRes += aFlowFanin / nRefs;
}
pM->AreaFlow = aFlowRes;
return aFlowRes;
}
/**function*************************************************************
synopsis [Computes the exact area associated with the cut.]
description [Assumes that the cut is referenced.]
sideeffects []
seealso []
***********************************************************************/
float Map_CutGetAreaRefed( Map_Cut_t * pCut, int fPhase )
{
float aResult, aResult2;
aResult2 = Map_CutRefDeref( pCut, fPhase, 0 ); // dereference
aResult = Map_CutRefDeref( pCut, fPhase, 1 ); // reference
assert( aResult == aResult2 );
return aResult;
}
/**function*************************************************************
synopsis [Computes the exact area associated with the cut.]
description []
sideeffects []
seealso []
***********************************************************************/
float Map_CutGetAreaDerefed( Map_Cut_t * pCut, int fPhase )
{
float aResult, aResult2;
aResult2 = Map_CutRefDeref( pCut, fPhase, 1 ); // reference
aResult = Map_CutRefDeref( pCut, fPhase, 0 ); // dereference
assert( aResult == aResult2 );
return aResult;
}
/**function*************************************************************
synopsis [References the cut.]
description []
sideeffects []
seealso []
***********************************************************************/
float Map_CutRef( Map_Cut_t * pCut, int fPhase )
{
return Map_CutRefDeref( pCut, fPhase, 1 ); // reference
}
/**function*************************************************************
synopsis [Dereferences the cut.]
description []
sideeffects []
seealso []
***********************************************************************/
float Map_CutDeref( Map_Cut_t * pCut, int fPhase )
{
return Map_CutRefDeref( pCut, fPhase, 0 ); // dereference
}
/**function*************************************************************
synopsis [References or dereferences the cut.]
description [This reference part is similar to Cudd_NodeReclaim().
The dereference part is similar to Cudd_RecursiveDeref().]
sideeffects []
seealso []
***********************************************************************/
float Map_CutRefDeref( Map_Cut_t * pCut, int fPhase, int fReference )
{
Map_Node_t * pNodeChild;
Map_Cut_t * pCutChild;
float aArea;
int i, fPhaseChild;
// int nRefs;
// consider the elementary variable
if ( pCut->nLeaves == 1 )
return 0;
// start the area of this cut
aArea = Map_CutGetRootArea( pCut, fPhase );
// go through the children
for ( i = 0; i < pCut->nLeaves; i++ )
{
pNodeChild = pCut->ppLeaves[i];
fPhaseChild = Map_CutGetLeafPhase( pCut, fPhase, i );
// get the reference counter of the child
/*
// this code does not take inverters into account
// the quality of area recovery seems to always be a little worse
if ( fReference )
nRefs = Map_NodeIncRefPhaseAct( pNodeChild, fPhaseChild );
else
nRefs = Map_NodeDecRefPhaseAct( pNodeChild, fPhaseChild );
assert( nRefs >= 0 );
// skip if the child was already reference before
if ( nRefs > 0 )
continue;
*/
if ( fReference )
{
if ( pNodeChild->pCutBest[0] && pNodeChild->pCutBest[1] ) // both phases are present
{
// if this phase of the node is referenced, there is no recursive call
pNodeChild->nRefAct[2]++;
if ( pNodeChild->nRefAct[fPhaseChild]++ > 0 )
continue;
}
else // only one phase is present
{
// inverter should be added if the phase
// (a) has no reference and (b) is implemented using other phase
if ( pNodeChild->nRefAct[fPhaseChild]++ == 0 && pNodeChild->pCutBest[fPhaseChild] == NULL )
aArea += pNodeChild->p->pSuperLib->AreaInv;
// if the node is referenced, there is no recursive call
if ( pNodeChild->nRefAct[2]++ > 0 )
continue;
}
}
else
{
if ( pNodeChild->pCutBest[0] && pNodeChild->pCutBest[1] ) // both phases are present
{
// if this phase of the node is referenced, there is no recursive call
--pNodeChild->nRefAct[2];
if ( --pNodeChild->nRefAct[fPhaseChild] > 0 )
continue;
}
else // only one phase is present
{
// inverter should be added if the phase
// (a) has no reference and (b) is implemented using other phase
if ( --pNodeChild->nRefAct[fPhaseChild] == 0 && pNodeChild->pCutBest[fPhaseChild] == NULL )
aArea += pNodeChild->p->pSuperLib->AreaInv;
// if the node is referenced, there is no recursive call
if ( --pNodeChild->nRefAct[2] > 0 )
continue;
}
assert( pNodeChild->nRefAct[fPhaseChild] >= 0 );
}
// get the child cut
pCutChild = pNodeChild->pCutBest[fPhaseChild];
// if the child does not have this phase mapped, take the opposite phase
if ( pCutChild == NULL )
{
fPhaseChild = !fPhaseChild;
pCutChild = pNodeChild->pCutBest[fPhaseChild];
}
// reference and compute area recursively
aArea += Map_CutRefDeref( pCutChild, fPhaseChild, fReference );
}
return aArea;
}
/**Function*************************************************************
Synopsis [Computes actual reference counters.]
Description [Collects the nodes used in the mapping in array pMan->vMapping.
Nodes are collected in reverse topological order to facilitate the
computation of required times.]
SideEffects []
SeeAlso []
***********************************************************************/
void Map_MappingSetRefs( Map_Man_t * pMan )
{
Map_Node_t * pNode, ** ppStore;
int i, fPhase, LevelMax;
// clean all references
for ( i = 0; i < pMan->vNodesAll->nSize; i++ )
{
pNode = pMan->vNodesAll->pArray[i];
pNode->nRefAct[0] = 0;
pNode->nRefAct[1] = 0;
pNode->nRefAct[2] = 0;
}
// find the largest level of a node
LevelMax = 0;
for ( i = 0; i < pMan->nOutputs; i++ )
if ( LevelMax < (int)Map_Regular(pMan->pOutputs[i])->Level )
LevelMax = Map_Regular(pMan->pOutputs[i])->Level;
// allocate place to store the nodes
ppStore = ALLOC( Map_Node_t *, LevelMax + 1 );
memset( ppStore, 0, sizeof(Map_Node_t *) * (LevelMax + 1) );
// visit nodes reachable from POs in the DFS order through the best cuts
for ( i = 0; i < pMan->nOutputs; i++ )
{
pNode = pMan->pOutputs[i];
fPhase = !Map_IsComplement(pNode);
if ( !Map_NodeIsConst(pNode) )
Map_MappingSetRefs_rec( pMan, pNode, ppStore );
}
// reconnect the nodes in reverse topological order
pMan->vMapping->nSize = 0;
for ( i = LevelMax; i >= 0; i-- )
for ( pNode = ppStore[i]; pNode; pNode = (Map_Node_t *)pNode->pData0 )
Map_NodeVecPush( pMan->vMapping, pNode );
free( ppStore );
}
/**Function*************************************************************
Synopsis [Recursively computes the DFS ordering of the nodes.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Map_MappingSetRefs_rec( Map_Man_t * pMan, Map_Node_t * pNode, Map_Node_t ** ppStore )
{
Map_Cut_t * pCut;
Map_Node_t * pNodeR;
unsigned uPhase;
int i, fPhase, fInvPin;
// get the regular node and its phase
pNodeR = Map_Regular(pNode);
fPhase = !Map_IsComplement(pNode);
// add the node to the list of all visited nodes
if ( pNodeR->nRefAct[2]++ == 0 )
// Map_NodeVecPush( pMan->vMapping, pNodeR );
pNodeR->pData0 = (char *)ppStore[pNodeR->Level], ppStore[pNodeR->Level] = pNodeR;
// quit if the node was already visited in this phase
if ( pNodeR->nRefAct[fPhase]++ )
return;
// quit if this is a PI node
if ( Map_NodeIsVar(pNodeR) )
return;
// get the cut implementing this or opposite polarity
pCut = pNodeR->pCutBest[fPhase];
if ( pCut == NULL )
{
fPhase = !fPhase;
pCut = pNodeR->pCutBest[fPhase];
}
// visit the transitive fanin
uPhase = pCut->M[fPhase].uPhaseBest;
for ( i = 0; i < pCut->nLeaves; i++ )
{
fInvPin = ((uPhase & (1 << i)) > 0);
Map_MappingSetRefs_rec( pMan, Map_NotCond(pCut->ppLeaves[i], fInvPin), ppStore );
}
}
/**Function*************************************************************
Synopsis [Computes the array of mapping.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
float Map_MappingGetArea( Map_Man_t * pMan, Map_NodeVec_t * vMapping )
{
Map_Node_t * pNode;
float Area;
int i;
Area = 0.0;
for ( i = 0; i < vMapping->nSize; i++ )
{
pNode = vMapping->pArray[i];
// at least one phase has the best cut assigned
assert( pNode->pCutBest[0] != NULL || pNode->pCutBest[1] != NULL );
// at least one phase is used in the mapping
assert( pNode->nRefAct[0] > 0 || pNode->nRefAct[1] > 0 );
// compute the array due to the supergate
if ( Map_NodeIsAnd(pNode) )
{
// count area of the negative phase
if ( pNode->pCutBest[0] && (pNode->nRefAct[0] > 0 || pNode->pCutBest[1] == NULL) )
Area += pNode->pCutBest[0]->M[0].pSuperBest->Area;
// count area of the positive phase
if ( pNode->pCutBest[1] && (pNode->nRefAct[1] > 0 || pNode->pCutBest[0] == NULL) )
Area += pNode->pCutBest[1]->M[1].pSuperBest->Area;
}
// count area of the interver if we need to implement one phase with another phase
if ( (pNode->pCutBest[0] == NULL && pNode->nRefAct[0] > 0) ||
(pNode->pCutBest[1] == NULL && pNode->nRefAct[1] > 0) )
Area += pMan->pSuperLib->AreaInv;
}
// add buffers for each CO driven by a CI
for ( i = 0; i < pMan->nOutputs; i++ )
if ( Map_NodeIsVar(pMan->pOutputs[i]) && !Map_IsComplement(pMan->pOutputs[i]) )
Area += pMan->pSuperLib->AreaBuf;
return Area;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
|
