/**Function*************************************************************
Synopsis [Computes the l-value of the node.]
Description [The node can be internal or a PO.]
SideEffects []
SeeAlso []
***********************************************************************/
int Seq_FpgaNodeUpdateLValue( Abc_Obj_t * pObj, int Fi )
{
Cut_Cut_t * pCut, * pList;
int lValueNew, lValueOld, lValueCut;
assert( !Abc_ObjIsPi(pObj) );
assert( Abc_ObjFaninNum(pObj) > 0 );
if ( Abc_ObjIsPo(pObj) )
{
lValueNew = Seq_NodeGetLValue(Abc_ObjFanin0(pObj)) - Fi * Seq_ObjFaninL0(pObj);
return (lValueNew > Fi)? SEQ_UPDATE_FAIL : SEQ_UPDATE_NO;
}
// get the arrival time of the best non-trivial cut
pList = Abc_NodeReadCuts( Seq_NodeCutMan(pObj), pObj );
// skip the choice nodes
if ( pList == NULL )
return SEQ_UPDATE_NO;
lValueNew = ABC_INFINITY;
for ( pCut = pList->pNext; pCut; pCut = pCut->pNext )
{
lValueCut = Seq_FpgaCutUpdateLValue( pCut, pObj, Fi );
if ( lValueNew > lValueCut )
lValueNew = lValueCut;
}
// compare the arrival time with the previous arrival time
lValueOld = Seq_NodeGetLValue(pObj);
// if ( lValueNew == lValueOld )
if ( lValueNew <= lValueOld )
return SEQ_UPDATE_NO;
Seq_NodeSetLValue( pObj, lValueNew );
//printf( "%d -> %d ", lValueOld, lValueNew );
return SEQ_UPDATE_YES;
}
/**Function*************************************************************
Synopsis [Retimes node forward by one latch.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Abc_ObjRetimeForward( Abc_Obj_t * pObj )
{
Abc_Obj_t * pFanout;
int Init0, Init1, Init, i;
assert( Abc_ObjFaninNum(pObj) == 2 );
assert( Seq_ObjFaninL0(pObj) >= 1 );
assert( Seq_ObjFaninL1(pObj) >= 1 );
// remove the init values from the fanins
Init0 = Seq_NodeDeleteFirst( pObj, 0 );
Init1 = Seq_NodeDeleteFirst( pObj, 1 );
assert( Init0 != ABC_INIT_NONE );
assert( Init1 != ABC_INIT_NONE );
// take into account the complements in the node
if ( Abc_ObjFaninC0(pObj) )
{
if ( Init0 == ABC_INIT_ZERO )
Init0 = ABC_INIT_ONE;
else if ( Init0 == ABC_INIT_ONE )
Init0 = ABC_INIT_ZERO;
}
if ( Abc_ObjFaninC1(pObj) )
{
if ( Init1 == ABC_INIT_ZERO )
Init1 = ABC_INIT_ONE;
else if ( Init1 == ABC_INIT_ONE )
Init1 = ABC_INIT_ZERO;
}
// compute the value at the output of the node
if ( Init0 == ABC_INIT_ZERO || Init1 == ABC_INIT_ZERO )
Init = ABC_INIT_ZERO;
else if ( Init0 == ABC_INIT_ONE && Init1 == ABC_INIT_ONE )
Init = ABC_INIT_ONE;
else
Init = ABC_INIT_DC;
// make sure the label is clean
Abc_ObjForEachFanout( pObj, pFanout, i )
assert( pFanout->fMarkC == 0 );
// add the init values to the fanouts
Abc_ObjForEachFanout( pObj, pFanout, i )
{
if ( pFanout->fMarkC )
continue;
pFanout->fMarkC = 1;
if ( Abc_ObjFaninId0(pFanout) != Abc_ObjFaninId1(pFanout) )
Seq_NodeInsertLast( pFanout, Abc_ObjFanoutEdgeNum(pObj, pFanout), Init );
else
{
assert( Abc_ObjFanin0(pFanout) == pObj );
Seq_NodeInsertLast( pFanout, 0, Init );
Seq_NodeInsertLast( pFanout, 1, Init );
}
}
// clean the label
Abc_ObjForEachFanout( pObj, pFanout, i )
pFanout->fMarkC = 0;
}
