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Diffstat (limited to 'src/opt/lpk/lpkAbcMux.c')
-rw-r--r-- | src/opt/lpk/lpkAbcMux.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/src/opt/lpk/lpkAbcMux.c b/src/opt/lpk/lpkAbcMux.c new file mode 100644 index 00000000..1525a7e0 --- /dev/null +++ b/src/opt/lpk/lpkAbcMux.c @@ -0,0 +1,254 @@ +/**CFile**************************************************************** + + FileName [lpkAbcMux.c] + + SystemName [ABC: Logic synthesis and verification system.] + + PackageName [Fast Boolean matching for LUT structures.] + + Synopsis [Iterative MUX decomposition.] + + Author [Alan Mishchenko] + + Affiliation [UC Berkeley] + + Date [Ver. 1.0. Started - April 28, 2007.] + + Revision [$Id: lpkAbcMux.c,v 1.00 2007/04/28 00:00:00 alanmi Exp $] + +***********************************************************************/ + +#include "lpkInt.h" + +//////////////////////////////////////////////////////////////////////// +/// DECLARATIONS /// +//////////////////////////////////////////////////////////////////////// + +//////////////////////////////////////////////////////////////////////// +/// FUNCTION DEFINITIONS /// +//////////////////////////////////////////////////////////////////////// + +/**Function************************************************************* + + Synopsis [Computes cofactors w.r.t. the given var.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Lpk_FunComputeCofs( Lpk_Fun_t * p, int iVar ) +{ + unsigned * pTruth = Lpk_FunTruth( p, 0 ); + unsigned * pTruth0 = Lpk_FunTruth( p, 1 ); + unsigned * pTruth1 = Lpk_FunTruth( p, 2 ); + Kit_TruthCofactor0New( pTruth0, pTruth, p->nVars, iVar ); + Kit_TruthCofactor1New( pTruth1, pTruth, p->nVars, iVar ); +} + + +/**Function************************************************************* + + Synopsis [Computes cofactors w.r.t. each variable.] + + Description [] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +void Lpk_FunComputeCofSupps( Lpk_Fun_t * p, unsigned * puSupps ) +{ + unsigned * pTruth = Lpk_FunTruth( p, 0 ); + unsigned * pTruth0 = Lpk_FunTruth( p, 1 ); + unsigned * pTruth1 = Lpk_FunTruth( p, 2 ); + int Var; + Lpk_SuppForEachVar( p->uSupp, Var ) + { + Lpk_FunComputeCofs( p, Var ); + puSupps[2*Var+0] = Kit_TruthSupport( pTruth0, p->nVars ); + puSupps[2*Var+1] = Kit_TruthSupport( pTruth1, p->nVars ); + } +} + +/**Function************************************************************* + + Synopsis [Checks the possibility of MUX decomposition.] + + Description [Returns the best variable to use for MUX decomposition.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +int Lpk_FunAnalizeMux( Lpk_Fun_t * p ) +{ + unsigned puSupps[32] = {0}; + int nSuppSize0, nSuppSize1, Delay, Delay0, Delay1, DelayA, DelayB; + int Var, Area, Polarity, VarBest, AreaBest, PolarityBest, nSuppSizeBest; + + if ( p->nVars > p->nAreaLim * (p->nLutK - 1) + 1 ) + return -1; + // get cofactor supports for each variable + Lpk_FunComputeCofSupps( p, puSupps ); + // derive the delay and area of each MUX-decomposition + VarBest = -1; + Lpk_SuppForEachVar( p->uSupp, Var ) + { + nSuppSize0 = Kit_WordCountOnes(puSupps[2*Var+0]); + nSuppSize1 = Kit_WordCountOnes(puSupps[2*Var+1]); + if ( nSuppSize0 <= (int)p->nLutK - 2 && nSuppSize1 <= (int)p->nLutK - 2 ) + { + // include cof var into 0-block + DelayA = Lpk_SuppDelay( puSupps[2*Var+0] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+1] , p->pDelays ); + Delay0 = ABC_MAX( DelayA, DelayB + 1 ); + // include cof var into 1-block + DelayA = Lpk_SuppDelay( puSupps[2*Var+1] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+0] , p->pDelays ); + Delay1 = ABC_MAX( DelayA, DelayB + 1 ); + // get the best delay + Delay = ABC_MIN( Delay0, Delay1 ); + Area = 2; + Polarity = (int)(Delay1 == Delay); + } + else if ( nSuppSize0 <= (int)p->nLutK - 2 ) + { + DelayA = Lpk_SuppDelay( puSupps[2*Var+0] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+1] , p->pDelays ); + Delay = ABC_MAX( DelayA, DelayB + 1 ); + Area = 1 + Lpk_LutNumLuts( nSuppSize1, p->nLutK ); + Polarity = 0; + } + else if ( nSuppSize0 <= (int)p->nLutK ) + { + DelayA = Lpk_SuppDelay( puSupps[2*Var+1] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+0] , p->pDelays ); + Delay = ABC_MAX( DelayA, DelayB + 1 ); + Area = 1 + Lpk_LutNumLuts( nSuppSize1+2, p->nLutK ); + Polarity = 1; + } + else if ( nSuppSize1 <= (int)p->nLutK - 2 ) + { + DelayA = Lpk_SuppDelay( puSupps[2*Var+1] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+0] , p->pDelays ); + Delay = ABC_MAX( DelayA, DelayB + 1 ); + Area = 1 + Lpk_LutNumLuts( nSuppSize0, p->nLutK ); + Polarity = 1; + } + else if ( nSuppSize1 <= (int)p->nLutK ) + { + DelayA = Lpk_SuppDelay( puSupps[2*Var+0] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+1] , p->pDelays ); + Delay = ABC_MAX( DelayA, DelayB + 1 ); + Area = 1 + Lpk_LutNumLuts( nSuppSize0+2, p->nLutK ); + Polarity = 0; + } + else + { + // include cof var into 0-block + DelayA = Lpk_SuppDelay( puSupps[2*Var+0] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+1] , p->pDelays ); + Delay0 = ABC_MAX( DelayA, DelayB + 1 ); + // include cof var into 1-block + DelayA = Lpk_SuppDelay( puSupps[2*Var+1] | (1<<Var), p->pDelays ); + DelayB = Lpk_SuppDelay( puSupps[2*Var+0] , p->pDelays ); + Delay1 = ABC_MAX( DelayA, DelayB + 1 ); + // get the best delay + Delay = ABC_MIN( Delay0, Delay1 ); + if ( Delay == Delay0 ) + Area = Lpk_LutNumLuts( nSuppSize0+2, p->nLutK ) + Lpk_LutNumLuts( nSuppSize1, p->nLutK ); + else + Area = Lpk_LutNumLuts( nSuppSize1+2, p->nLutK ) + Lpk_LutNumLuts( nSuppSize0, p->nLutK ); + Polarity = (int)(Delay1 == Delay); + } + // find the best variable + if ( Delay > (int)p->nDelayLim ) + continue; + if ( Area > (int)p->nAreaLim ) + continue; + if ( VarBest == -1 || AreaBest > Area || (AreaBest == Area && nSuppSizeBest > nSuppSize0+nSuppSize1) ) + { + VarBest = Var; + AreaBest = Area; + PolarityBest = Polarity; + nSuppSizeBest = nSuppSize0+nSuppSize1; + } + } + return (VarBest == -1)? -1 : (2*VarBest + Polarity); +} + +/**Function************************************************************* + + Synopsis [Transforms the function decomposed by the MUX decomposition.] + + Description [Returns the best variable to use for MUX decomposition.] + + SideEffects [] + + SeeAlso [] + +***********************************************************************/ +Lpk_Fun_t * Lpk_FunSplitMux( Lpk_Fun_t * p, int VarPol ) +{ + Lpk_Fun_t * pNew; + unsigned * pTruth = Lpk_FunTruth( p, 0 ); + unsigned * pTruth0 = Lpk_FunTruth( p, 1 ); + unsigned * pTruth1 = Lpk_FunTruth( p, 2 ); + int Var = VarPol / 2; + int Pol = VarPol % 2; + int iVarVac; + assert( VarPol >= 0 && VarPol < 2 * (int)p->nVars ); + assert( p->nAreaLim >= 2 ); + Lpk_FunComputeCofs( p, Var ); + if ( Pol == 0 ) + { + // derive the new component + pNew = Lpk_FunDup( p, pTruth1 ); + // update the old component + p->uSupp = Kit_TruthSupport( pTruth0, p->nVars ); + iVarVac = Kit_WordFindFirstBit( ~(p->uSupp | (1 << Var)) ); + assert( iVarVac < (int)p->nVars ); + Kit_TruthIthVar( pTruth, p->nVars, iVarVac ); + // update the truth table + Kit_TruthMux( pTruth, pTruth0, pTruth1, pTruth, p->nVars ); + p->pFanins[iVarVac] = pNew->Id; + p->pDelays[iVarVac] = Lpk_SuppDelay( pNew->uSupp, pNew->pDelays ); + // support minimize both + Lpk_FunSuppMinimize( p ); + Lpk_FunSuppMinimize( pNew ); + // update delay and area requirements + pNew->nDelayLim = p->nDelayLim - 1; + if ( p->nVars <= p->nLutK ) + { + pNew->nAreaLim = p->nAreaLim - 1; + p->nAreaLim = 1; + } + else if ( pNew->nVars <= pNew->nLutK ) + { + pNew->nAreaLim = 1; + p->nAreaLim = p->nAreaLim - 1; + } + else if ( p->nVars < pNew->nVars ) + { + pNew->nAreaLim = p->nAreaLim / 2 + p->nAreaLim % 2; + p->nAreaLim = p->nAreaLim / 2 - p->nAreaLim % 2; + } + else // if ( pNew->nVars < p->nVars ) + { + pNew->nAreaLim = p->nAreaLim / 2 - p->nAreaLim % 2; + p->nAreaLim = p->nAreaLim / 2 + p->nAreaLim % 2; + } + } + return p; +} + +//////////////////////////////////////////////////////////////////////// +/// END OF FILE /// +//////////////////////////////////////////////////////////////////////// + + |