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Diffstat (limited to 'src/proof/llb/llb1Sched.c')
| -rw-r--r-- | src/proof/llb/llb1Sched.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/src/proof/llb/llb1Sched.c b/src/proof/llb/llb1Sched.c new file mode 100644 index 00000000..6bdae42e --- /dev/null +++ b/src/proof/llb/llb1Sched.c @@ -0,0 +1,257 @@ +/**CFile**************************************************************** + + FileName [llb1Sched.c] + + SystemName [ABC: Logic synthesis and verification system.] + + PackageName [BDD based reachability.] + + Synopsis [Partition scheduling algorithm.] + + Author [Alan Mishchenko] + + Affiliation [UC Berkeley] + + Date [Ver. 1.0. Started - June 20, 2005.] + + Revision [$Id: llb1Sched.c,v 1.00 2005/06/20 00:00:00 alanmi Exp $] + +***********************************************************************/ + +#include "llbInt.h" + +ABC_NAMESPACE_IMPL_START + + +//////////////////////////////////////////////////////////////////////// +/// DECLARATIONS /// +//////////////////////////////////////////////////////////////////////// + +//////////////////////////////////////////////////////////////////////// +/// FUNCTION DEFINITIONS /// +//////////////////////////////////////////////////////////////////////// + +/**Function************************************************************* + + Synopsis [Swaps two rows.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Llb_MtrSwapColumns( Llb_Mtr_t * p, int iCol1, int iCol2 ) +{ + Llb_Grp_t * pGemp; + char * pTemp; + int iTemp; + assert( iCol1 >= 0 && iCol1 < p->nCols ); + assert( iCol2 >= 0 && iCol2 < p->nCols ); + if ( iCol1 == iCol2 ) + return; + assert( iCol1 != iCol2 ); + // swap col groups + pGemp = p->pColGrps[iCol1]; + p->pColGrps[iCol1] = p->pColGrps[iCol2]; + p->pColGrps[iCol2] = pGemp; + // swap col vectors + pTemp = p->pMatrix[iCol1]; + p->pMatrix[iCol1] = p->pMatrix[iCol2]; + p->pMatrix[iCol2] = pTemp; + // swap col sums + iTemp = p->pColSums[iCol1]; + p->pColSums[iCol1] = p->pColSums[iCol2]; + p->pColSums[iCol2] = iTemp; +} + +/**Function************************************************************* + + Synopsis [Find columns which brings as few vars as possible.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Llb_MtrFindBestColumn( Llb_Mtr_t * p, int iGrpStart ) +{ + int Cost, Cost2, CostBest = ABC_INFINITY, Cost2Best = ABC_INFINITY; + int WeightCur, WeightBest = -ABC_INFINITY, iGrp, iGrpBest = -1; + int k, c, iVar, Counter; + // find partition that reduces partial product as much as possible + for ( iVar = 0; iVar < p->nRows - p->nFfs; iVar++ ) + { + if ( p->pRowSums[iVar] < 2 ) + continue; + // look at present variables that can be quantified + if ( !(p->pProdVars[iVar] == 1 && p->pProdNums[iVar] == 1) ) + continue; + // check that it appears in one partition only + Counter = 0; + for ( c = iGrpStart; c < p->nCols-1; c++ ) + if ( p->pMatrix[c][iVar] == 1 ) + { + iGrp = c; + Counter++; + } + assert( Counter == 1 ); + if ( Counter != 1 ) + Abc_Print( -1, "Llb_MtrFindBestColumn() Internal error!\n" ); + // find weight of this column + WeightCur = 0; + for ( k = 0; k < p->nRows; k++ ) + { + // increase weight if variable k will be quantified from partial product + if ( p->pProdVars[k] == 1 && p->pMatrix[iGrp][k] == 1 && p->pProdNums[k] == 1 ) + WeightCur += 2; + // decrease weight if variable k will be added to partial product + if ( p->pProdVars[k] == 0 && p->pMatrix[iGrp][k] == 1 ) + WeightCur--; + } + if ( WeightCur > 0 && WeightBest < WeightCur ) + { + WeightBest = WeightCur; + iGrpBest = iGrp; + } + } + if ( iGrpBest >= 0 ) + return iGrpBest; + // could not find the group with any vars to quantify + // select the group that contains as few extra variables as possible + // if there is a tie, select variables that appear in less groups than others + for ( iGrp = iGrpStart; iGrp < p->nCols-1; iGrp++ ) + { + Cost = Cost2 = 0; + for ( k = 0; k < p->nRows; k++ ) + if ( p->pProdVars[k] == 0 && p->pMatrix[iGrp][k] == 1 ) + { + Cost++; + Cost2 += p->pProdNums[k]; + } + if ( CostBest > Cost || + (CostBest == Cost && Cost2 > Cost2Best) ) + { + CostBest = Cost; + Cost2Best = Cost2; + iGrpBest = iGrp; + } + } + return iGrpBest; +} + +/**Function************************************************************* + + Synopsis [Returns the number of variables that will be saved.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Llb_MtrUseSelectedColumn( Llb_Mtr_t * p, int iCol ) +{ + int iVar; + assert( iCol >= 1 && iCol < p->nCols - 1 ); + for ( iVar = 0; iVar < p->nRows; iVar++ ) + { + if ( p->pMatrix[iCol][iVar] == 0 ) + continue; + if ( p->pProdVars[iVar] == 1 && p->pProdNums[iVar] == 1 ) + { + p->pProdVars[iVar] = 0; + p->pProdNums[iVar] = 0; + continue; + } + if ( p->pProdVars[iVar] == 0 ) + { + p->pProdVars[iVar] = 1; + p->pProdNums[iVar] = p->pRowSums[iVar]; + } + p->pProdNums[iVar]--; + assert( p->pProdNums[iVar] >= 0 ); + if ( p->pProdNums[iVar] < 0 ) + Abc_Print( -1, "Llb_MtrUseSelectedColumn() Internal error!\n" ); + } +} + +/**Function************************************************************* + + Synopsis [Verify columns.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Llb_MtrVerifyColumns( Llb_Mtr_t * p, int iGrpStart ) +{ + int iVar, iGrp, Counter; + for ( iVar = 0; iVar < p->nRows; iVar++ ) + { + if ( p->pProdVars[iVar] == 0 ) + continue; + Counter = 0; + for ( iGrp = iGrpStart; iGrp < p->nCols; iGrp++ ) + if ( p->pMatrix[iGrp][iVar] == 1 ) + Counter++; + assert( Counter == p->pProdNums[iVar] ); + if ( Counter != p->pProdNums[iVar] ) + Abc_Print( -1, "Llb_MtrVerifyColumns(): Internal error.\n" ); + } +} + +/**Function************************************************************* + + Synopsis [Matrix reduce.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Llb_MtrSchedule( Llb_Mtr_t * p ) +{ + int iGrp, iGrpBest, i; + // start partial product + for ( i = 0; i < p->nRows; i++ ) + { + if ( i >= p->nPis && i < p->nPis + p->nFfs ) + { + p->pProdVars[i] = 1; + p->pProdNums[i] = p->pRowSums[i] - 1; + } + else + { + p->pProdVars[i] = 0; + p->pProdNums[i] = p->pRowSums[i]; + } + } + // order the partitions + Llb_MtrVerifyMatrix( p ); + for ( iGrp = 1; iGrp < p->nCols-1; iGrp++ ) + { + Llb_MtrVerifyColumns( p, iGrp ); + iGrpBest = Llb_MtrFindBestColumn( p, iGrp ); + Llb_MtrUseSelectedColumn( p, iGrpBest ); + Llb_MtrSwapColumns( p, iGrp, iGrpBest ); + } + Llb_MtrVerifyMatrix( p ); +} + +//////////////////////////////////////////////////////////////////////// +/// END OF FILE /// +//////////////////////////////////////////////////////////////////////// + + +ABC_NAMESPACE_IMPL_END + |