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| author | Alan Mishchenko <alanmi@berkeley.edu> | 2006-11-22 08:01:00 -0800 |
|---|---|---|
| committer | Alan Mishchenko <alanmi@berkeley.edu> | 2006-11-22 08:01:00 -0800 |
| commit | 6ad22b4d3b0446652919d95b15fefb374bddfac0 (patch) | |
| tree | eb525005c9827e844464c4e787c5907c7edc1d5c /src/opt/ret/retDelay.c | |
| parent | da5e0785dfb98335bd49a13bf9e86e736fb931be (diff) | |
| download | abc-6ad22b4d3b0446652919d95b15fefb374bddfac0.tar.gz abc-6ad22b4d3b0446652919d95b15fefb374bddfac0.tar.bz2 abc-6ad22b4d3b0446652919d95b15fefb374bddfac0.zip | |
Version abc61122
Diffstat (limited to 'src/opt/ret/retDelay.c')
| -rw-r--r-- | src/opt/ret/retDelay.c | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/src/opt/ret/retDelay.c b/src/opt/ret/retDelay.c index d2d87447..80c75729 100644 --- a/src/opt/ret/retDelay.c +++ b/src/opt/ret/retDelay.c @@ -76,7 +76,7 @@ int Abc_NtkRetimeMinDelayTry( Abc_Ntk_t * pNtk, int fForward, int fInitial, int Vec_Ptr_t * vCritical; Vec_Int_t * vValues; Abc_Obj_t * pObj; - int i, k, IterBest, DelayCur, DelayBest, DelayStart; + int i, k, IterBest, DelayCur, DelayBest, DelayStart, LatchesBest; // transfer intitial values if ( fInitial ) { @@ -90,8 +90,15 @@ int Abc_NtkRetimeMinDelayTry( Abc_Ntk_t * pNtk, int fForward, int fInitial, int pNtkNew = Abc_NtkRetimeBackwardInitialStart( pNtk ); } } +if ( fVerbose ) +{ + if ( !fInitial ) + printf( "Performing analysis:\n" ); + else + printf( "Moving latches to the best position:\n" ); +} // find the best iteration - DelayBest = ABC_INFINITY; IterBest = 0; + DelayBest = ABC_INFINITY; IterBest = 0; LatchesBest = Abc_NtkLatchNum(pNtk); vCritical = Vec_PtrAlloc( 100 ); for ( i = 0; ; i++ ) { @@ -102,16 +109,29 @@ int Abc_NtkRetimeMinDelayTry( Abc_Ntk_t * pNtk, int fForward, int fInitial, int // record this position if it has the best delay if ( DelayBest > DelayCur ) { +if ( fVerbose ) + printf( "%s Iter = %3d. Delay = %3d. Latches = %5d. Delta = %6.2f. Ratio = %4.2f %%\n", + fForward ? "Fwd": "Bwd", i, DelayCur, Abc_NtkLatchNum(pNtk), + 1.0*(Abc_NtkLatchNum(pNtk)-LatchesBest)/(DelayBest-DelayCur), + 100.0*(Abc_NtkLatchNum(pNtk)-LatchesBest)/Abc_NtkLatchNum(pNtk)/(DelayBest-DelayCur) ); + DelayBest = DelayCur; IterBest = i; + LatchesBest = Abc_NtkLatchNum(pNtk); } // quit after timing analysis if ( i == nIterLimit ) break; + // skip if 10 interations did not give improvement + if ( i - IterBest > 20 ) + break; // try retiming to improve the delay Vec_PtrForEachEntry( vCritical, pObj, k ) if ( Abc_NtkRetimeNodeIsEnabled(pObj, fForward) ) Abc_NtkRetimeNode( pObj, fForward, fInitial ); + // share latches + if ( !fForward ) + Abc_NtkRetimeShareLatches( pNtk, fInitial ); } Vec_PtrFree( vCritical ); // transfer the initial state back to the latches |