mirror of https://github.com/YosysHQ/abc.git
Improved DSD.
This commit is contained in:
Alan Mishchenko
parent
96d3348d8f
commit
b9c22ba99a
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@ -172,6 +172,17 @@ static inline int Abc_TtIsConst1( word * pIn1, int nWords )
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SeeAlso []
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***********************************************************************/
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static inline word Abc_Tt6Cofactor0( word t, int iVar )
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{
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assert( iVar >= 0 && iVar < 6 );
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return (t &s_Truths6Neg[iVar]) | ((t &s_Truths6Neg[iVar]) << (1<<iVar));
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}
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static inline word Abc_Tt6Cofactor1( word t, int iVar )
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{
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assert( iVar >= 0 && iVar < 6 );
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return (t & s_Truths6[iVar]) | ((t & s_Truths6[iVar]) >> (1<<iVar));
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}
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static inline void Abc_TtCofactor0( word * pTruth, int nWords, int iVar )
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{
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if ( nWords == 1 )
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@ -289,18 +300,10 @@ static inline int Abc_Tt6Cof0IsConst0( word t, int iVar ) { return (t & s_Truths
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static inline int Abc_Tt6Cof0IsConst1( word t, int iVar ) { return (t & s_Truths6Neg[iVar]) == s_Truths6Neg[iVar]; }
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static inline int Abc_Tt6Cof1IsConst0( word t, int iVar ) { return (t & s_Truths6[iVar]) == 0; }
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static inline int Abc_Tt6Cof1IsConst1( word t, int iVar ) { return (t & s_Truths6[iVar]) == s_Truths6[iVar]; }
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static inline int Abc_Tt6CofsOpposite( word t, int iVar ) { return ((t >> (1 << iVar)) & s_Truths6Neg[iVar]) == (~t & s_Truths6Neg[iVar]); }
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static inline word Abc_Tt6Cofactor0( word t, int iVar )
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{
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assert( iVar >= 0 && iVar < 6 );
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return (t &s_Truths6Neg[iVar]) | ((t &s_Truths6Neg[iVar]) << (1<<iVar));
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}
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static inline word Abc_Tt6Cofactor1( word t, int iVar )
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{
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assert( iVar >= 0 && iVar < 6 );
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return (t & s_Truths6[iVar]) | ((t & s_Truths6[iVar]) >> (1<<iVar));
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}
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static inline int Abc_Tt6CofsOpposite( word t, int iVar ) { return (~t & s_Truths6Neg[iVar]) == ((t >> (1 << iVar)) & s_Truths6Neg[iVar]); }
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static inline int Abc_Tt6Cof0EqualCof1( word t1, word t2, int iVar ) { return (t1 & s_Truths6Neg[iVar]) == ((t2 >> (1 << iVar)) & s_Truths6Neg[iVar]); }
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static inline int Abc_Tt6Cof0EqualCof0( word t1, word t2, int iVar ) { return (t1 & s_Truths6Neg[iVar]) == (t2 & s_Truths6Neg[iVar]); }
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static inline int Abc_Tt6Cof1EqualCof1( word t1, word t2, int iVar ) { return (t1 & s_Truths6[iVar]) == (t2 & s_Truths6[iVar]); }
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/**Function*************************************************************
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@ -433,13 +436,12 @@ static inline int Abc_TtCofsOpposite( word * t, int nWords, int iVar )
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SeeAlso []
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***********************************************************************/
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static inline void Abc_TtPrintDigit( int Digit )
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static inline char Abc_TtPrintDigit( int Digit )
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{
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assert( Digit >= 0 && Digit < 16 );
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if ( Digit < 10 )
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printf( "%d", Digit );
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else
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printf( "%c", 'A' + Digit-10 );
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return '0' + Digit;;
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return 'A' + Digit-10;
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}
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static inline void Abc_TtPrintHex( word * pTruth, int nVars )
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{
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@ -448,7 +450,7 @@ static inline void Abc_TtPrintHex( word * pTruth, int nVars )
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assert( nVars >= 2 );
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for ( pThis = pTruth; pThis < pLimit; pThis++ )
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for ( k = 0; k < 16; k++ )
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Abc_TtPrintDigit( (int)(pThis[0] >> (k << 2)) & 15 );
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printf( "%c", Abc_TtPrintDigit((int)(pThis[0] >> (k << 2)) & 15) );
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printf( "\n" );
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}
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static inline void Abc_TtPrintHexRev( word * pTruth, int nVars )
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@ -458,7 +460,7 @@ static inline void Abc_TtPrintHexRev( word * pTruth, int nVars )
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assert( nVars >= 2 );
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for ( pThis = pTruth + Abc_TtWordNum(nVars) - 1; pThis >= pTruth; pThis-- )
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for ( k = 15; k >= 0; k-- )
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Abc_TtPrintDigit( (int)(pThis[0] >> (k << 2)) & 15 );
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printf( "%c", Abc_TtPrintDigit((int)(pThis[0] >> (k << 2)) & 15) );
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printf( "\n" );
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}
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static inline void Abc_TtPrintHexSpecial( word * pTruth, int nVars )
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@ -468,9 +470,20 @@ static inline void Abc_TtPrintHexSpecial( word * pTruth, int nVars )
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assert( nVars >= 2 );
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for ( pThis = pTruth + Abc_TtWordNum(nVars) - 1; pThis >= pTruth; pThis-- )
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for ( k = 0; k < 16; k++ )
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Abc_TtPrintDigit( (int)(pThis[0] >> (k << 2)) & 15 );
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printf( "%c", Abc_TtPrintDigit((int)(pThis[0] >> (k << 2)) & 15) );
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printf( "\n" );
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}
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static inline int Abc_TtWriteHexRev( char * pStr, word * pTruth, int nVars )
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{
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word * pThis;
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char * pStrInit = pStr;
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int k, StartK = nVars >= 6 ? 16 : (1 << (nVars - 2));
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assert( nVars >= 2 );
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for ( pThis = pTruth + Abc_TtWordNum(nVars) - 1; pThis >= pTruth; pThis-- )
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for ( k = StartK - 1; k >= 0; k-- )
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*pStr++ = Abc_TtPrintDigit( (int)(pThis[0] >> (k << 2)) & 15 );
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return pStr - pStrInit;
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}
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/**Function*************************************************************
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@ -531,11 +544,13 @@ static inline int Abc_Tt6HasVar( word t, int iVar )
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}
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static inline int Abc_TtHasVar( word * t, int nVars, int iVar )
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{
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int nWords = Abc_TtWordNum( nVars );
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assert( iVar < nVars );
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if ( nVars <= 6 )
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return Abc_Tt6HasVar( t[0], iVar );
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if ( iVar < 6 )
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{
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int i, Shift = (1 << iVar);
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int nWords = Abc_TtWordNum( nVars );
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for ( i = 0; i < nWords; i++ )
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if ( ((t[i] >> Shift) & s_Truths6Neg[iVar]) != (t[i] & s_Truths6Neg[iVar]) )
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return 1;
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@ -544,7 +559,7 @@ static inline int Abc_TtHasVar( word * t, int nVars, int iVar )
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else
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{
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int i, Step = (1 << (iVar - 6));
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word * tLimit = t + nWords;
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word * tLimit = t + Abc_TtWordNum( nVars );
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for ( ; t < tLimit; t += 2*Step )
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for ( i = 0; i < Step; i++ )
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if ( t[i] != t[Step+i] )
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@ -711,6 +711,8 @@ struct Dau_Dsd_t_
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char pVarDefs[32][8]; // variable definitions
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char pOutput[DAU_MAX_STR]; // output stream
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int nPos; // writing position
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int nConsts; // the number of constant decompositions
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int uConstMask; // constant decomposition mask
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};
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/**Function*************************************************************
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@ -742,19 +744,31 @@ void Dua_DsdWriteInv( Dau_Dsd_t * p, int Cond )
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if ( Cond )
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p->pOutput[ p->nPos++ ] = '!';
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}
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void Dua_DsdWriteVar( Dau_Dsd_t * p, int iVar )
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void Dua_DsdWriteVar( Dau_Dsd_t * p, int iVar, int fInv )
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{
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char * pStr;
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if ( fInv )
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p->pOutput[ p->nPos++ ] = '!';
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for ( pStr = p->pVarDefs[iVar]; *pStr; pStr++ )
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if ( *pStr >= 'a' + p->nVarsInit && *pStr < 'a' + p->nVarsUsed )
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Dua_DsdWriteVar( p, *pStr - 'a' );
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Dua_DsdWriteVar( p, *pStr - 'a', 0 );
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else
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p->pOutput[ p->nPos++ ] = *pStr;
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}
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void Dua_DsdWriteStop( Dau_Dsd_t * p )
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{
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int i;
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for ( i = 0; i < p->nConsts; i++ )
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p->pOutput[ p->nPos++ ] = ((p->uConstMask >> i) & 1) ? ']' : ')';
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p->pOutput[ p->nPos++ ] = 0;
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}
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int Dua_DsdAddVarDef( Dau_Dsd_t * p, char * pStr )
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{
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assert( strlen(pStr) < 8 );
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assert( p->nVarsUsed < 32 );
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sprintf( p->pVarDefs[p->nVarsUsed++], "%s", pStr );
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return p->nVarsUsed - 1;
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}
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/**Function*************************************************************
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@ -767,18 +781,24 @@ void Dua_DsdWriteStop( Dau_Dsd_t * p )
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SeeAlso []
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***********************************************************************/
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int Dua_DsdMinBase( word t, int nVars, int * pVarsNew )
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int Dua_DsdMinBase( word * pTruth, int nVars, int * pVarsNew )
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{
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int v, nVarsNew = 0;
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int v;
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for ( v = 0; v < nVars; v++ )
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if ( Abc_Tt6HasVar( t, v ) )
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pVarsNew[nVarsNew++] = v;
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return nVarsNew;
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pVarsNew[v] = v;
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for ( v = nVars - 1; v >= 0; v-- )
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{
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if ( Abc_TtHasVar( pTruth, nVars, v ) )
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continue;
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Abc_TtSwapVars( pTruth, nVars, v, nVars-1 );
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pVarsNew[v] = pVarsNew[--nVars];
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}
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return nVars;
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}
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/**Function*************************************************************
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Synopsis []
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Synopsis [Returns 1 if constant cofactor is found.]
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Description []
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@ -787,29 +807,206 @@ int Dua_DsdMinBase( word t, int nVars, int * pVarsNew )
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SeeAlso []
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***********************************************************************/
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void Dau_DsdDecomposeInternal( Dau_Dsd_t * p, word t, int * pVars, int nVars )
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int Dau_Dsd6DecomposeConstCofOne( Dau_Dsd_t * p, word * pTruth, int * pVars, int nVars, int v )
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{
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}
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char * Dau_DsdDecompose( word t, int nVarsInit )
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{
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Dau_Dsd_t P, * p = &P;
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int nVars, pVars[6];
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Dua_DsdInit( p, nVarsInit );
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if ( t == 0 )
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Dua_DsdWrite( p, "0" );
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else if ( ~t == 0 )
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Dua_DsdWrite( p, "1" );
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int nConstOld = p->nConsts;
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// consider negative cofactors
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if ( pTruth[0] & 1 )
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{
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if ( Abc_Tt6Cof0IsConst1( pTruth[0], v ) ) // !(ax)
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{
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Dua_DsdWrite( p, "!(" );
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pTruth[0] = ~Abc_Tt6Cofactor1( pTruth[0], v );
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p->nConsts++;
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}
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}
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else
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{
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nVars = Dua_DsdMinBase( t, nVarsInit, pVars );
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if ( Abc_Tt6Cof0IsConst0( pTruth[0], v ) ) // ax
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{
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Dua_DsdWrite( p, "(" );
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pTruth[0] = Abc_Tt6Cofactor1( pTruth[0], v );
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p->nConsts++;
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}
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}
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// consider positive cofactors
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if ( pTruth[0] >> 63 )
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{
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if ( Abc_Tt6Cof1IsConst1( pTruth[0], v ) ) // !(!ax)
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{
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Dua_DsdWrite( p, "!(!" );
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pTruth[0] = ~Abc_Tt6Cofactor0( pTruth[0], v );
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p->nConsts++;
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}
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}
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else
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{
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if ( Abc_Tt6Cof1IsConst0( pTruth[0], v ) ) // !ax
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{
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Dua_DsdWrite( p, "(!" );
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pTruth[0] = Abc_Tt6Cofactor0( pTruth[0], v );
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p->nConsts++;
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}
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}
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// consider equal cofactors
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if ( Abc_Tt6CofsOpposite( pTruth[0], v ) ) // [ax]
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{
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Dua_DsdWrite( p, "[" );
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pTruth[0] = Abc_Tt6Cofactor0( pTruth[0], v );
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p->uConstMask |= (1 << p->nConsts++);
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}
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if ( nConstOld == p->nConsts )
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return 0;
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Dua_DsdWriteVar( p, pVars[v], 0 );
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pVars[v] = pVars[nVars-1];
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Abc_TtSwapVars( pTruth, 6, v, nVars-1 );
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return 1;
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}
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int Dau_Dsd6DecomposeConstCof( Dau_Dsd_t * p, word * pTruth, int * pVars, int nVars )
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{
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int v;
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assert( nVars > 1 );
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for ( v = nVars - 1; v >= 0 && nVars > 1; v++ )
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if ( Dau_Dsd6DecomposeConstCofOne( p, pTruth, pVars, nVars, v ) )
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nVars--;
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if ( nVars == 1 )
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Dua_DsdWriteVar( p, pVars[--nVars], (int)(pTruth[0] & 1) );
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return nVars;
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}
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void Dau_Dsd6DecomposeInternal( Dau_Dsd_t * p, word t, int * pVars, int nVars )
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{
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char pBuffer[10];
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int v, u;
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nVars = Dau_Dsd6DecomposeConstCof( p, &t, pVars, nVars );
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if ( nVars == 0 )
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return;
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// consider two-variable cofactors
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for ( v = nVars - 1; v > 0; v-- )
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{
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word tCof0 = Abc_Tt6Cofactor0( t, v );
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word tCof1 = Abc_Tt6Cofactor1( t, v );
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unsigned uSupp0 = 0, uSupp1 = 0;
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for ( u = v - 1; u >= 0; u-- )
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{
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if ( Abc_Tt6HasVar(tCof0, u) )
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{
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uSupp0 |= (1 << u);
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if ( Abc_Tt6HasVar(tCof1, u) )
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{
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uSupp1 |= (1 << u);
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// both F(v=0) and F(v=1) depend on u
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if ( Abc_Tt6Cof0EqualCof1(tCof0, tCof1, u) && Abc_Tt6Cof0EqualCof1(tCof1, tCof0, u) )
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{
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// perform XOR (u, v)
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t = (s_Truths6[u] & tCof1) | (~s_Truths6[u] & tCof0);
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sprintf( pBuffer, "[%c%c]", 'a' + pVars[v], 'a' + pVars[u] );
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break;
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}
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}
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else
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{
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// F(v=0) does not depend on u; F(v=1) depends on u
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if ( Abc_Tt6Cof0EqualCof0(tCof0, tCof1, u) )
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{
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// perform AND (u, v)
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break;
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}
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if ( Abc_Tt6Cof0EqualCof1(tCof0, tCof1, u) )
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{
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// perform AND (u, v)
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break;
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}
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}
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}
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else if ( Abc_Tt6HasVar(tCof1, u) )
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{
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uSupp1 |= (1 << u);
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// F(v=0) depends on u; F(v=1) does not depend on u
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if ( Abc_Tt6Cof0EqualCof0(tCof0, tCof1, u) )
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{
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// perform AND (u, v)
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break;
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}
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if ( Abc_Tt6Cof0EqualCof1(tCof0, tCof1, u) )
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{
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// perform AND (u, v)
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break;
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}
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}
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else assert( 0 ); // should depend on u
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}
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// check if decomposition happened
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if ( u >= 0 )
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{
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// finalize decomposition
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pVars[u] = Dua_DsdAddVarDef( p, pBuffer );
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pVars[v] = pVars[nVars-1];
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Abc_TtSwapVars( &t, 6, v, nVars-1 );
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nVars = Dau_Dsd6DecomposeConstCof( p, &t, pVars, --nVars );
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if ( nVars == 0 )
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return;
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continue;
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}
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// check MUX decomposition w.r.t. u
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if ( Abc_TtSuppOnlyOne( uSupp0 & ~uSupp1 ) && Abc_TtSuppOnlyOne( ~uSupp0 & uSupp1 ) )
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{
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// check MUX
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int iVar0 = Abc_TtSuppFindFirst( uSupp0 );
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int iVar1 = Abc_TtSuppFindFirst( uSupp1 );
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int fEqual0, fEqual1;
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if ( iVar0 > iVar1 )
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ABC_SWAP( int, iVar0, iVar1 );
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// check existence conditions
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assert( iVar0 < iVar1 );
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fEqual0 = Abc_TtCheckEqualCofs( &t, 1, iVar0, iVar1, 0, 2 ) && Abc_TtCheckEqualCofs( &t, 1, iVar0, iVar1, 1, 3 );
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fEqual1 = Abc_TtCheckEqualCofs( &t, 1, iVar0, iVar1, 0, 3 ) && Abc_TtCheckEqualCofs( &t, 1, iVar0, iVar1, 1, 2 );
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if ( fEqual0 || fEqual1 )
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{
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// perform MUX( v, F(v=1), F(v=0) )
|
||||
break;
|
||||
}
|
||||
}
|
||||
// check MUX decomposition w.r.t. u
|
||||
if ( (uSupp0 & uSupp1) == 0 )
|
||||
{
|
||||
// perform MUX( v, F(v=1), F(v=0) )
|
||||
}
|
||||
}
|
||||
// this non-DSD-decomposable function
|
||||
assert( nVars > 2 );
|
||||
// write truth table
|
||||
p->nPos += Abc_TtWriteHexRev( p->pOutput + p->nPos, &t, nVars );
|
||||
Dua_DsdWrite( p, "{" );
|
||||
for ( v = 0; v < nVars; v++ )
|
||||
Dua_DsdWriteVar( p, pVars[v], 0 );
|
||||
Dua_DsdWrite( p, "}" );
|
||||
}
|
||||
void Dau_DsdDecomposeInternal( Dau_Dsd_t * p, word * pTruth, int * pVars, int nVars )
|
||||
{
|
||||
}
|
||||
char * Dau_DsdDecompose( word * pTruth, int nVarsInit )
|
||||
{
|
||||
Dau_Dsd_t P, * p = &P;
|
||||
int nVars, pVars[16];
|
||||
Dua_DsdInit( p, nVarsInit );
|
||||
if ( (pTruth[0] & 1) == 0 && Abc_TtIsConst0(pTruth, Abc_TtWordNum(nVarsInit)) )
|
||||
Dua_DsdWrite( p, "0" );
|
||||
else if ( (pTruth[0] & 1) && Abc_TtIsConst1(pTruth, Abc_TtWordNum(nVarsInit)) )
|
||||
Dua_DsdWrite( p, "1" );
|
||||
else
|
||||
{
|
||||
nVars = Dua_DsdMinBase( pTruth, nVarsInit, pVars );
|
||||
assert( nVars > 0 && nVars < 6 );
|
||||
if ( nVars == 1 )
|
||||
{
|
||||
Dua_DsdWriteInv( p, (int)(t & 1) );
|
||||
Dua_DsdWriteVar( p, pVars[0] );
|
||||
}
|
||||
Dua_DsdWriteVar( p, pVars[0], (int)(pTruth[0] & 1) );
|
||||
else if ( nVars <= 6 )
|
||||
Dau_Dsd6DecomposeInternal( p, pTruth[0], pVars, nVars );
|
||||
else
|
||||
Dau_DsdDecomposeInternal( p, t, pVars, nVars );
|
||||
Dau_DsdDecomposeInternal( p, pTruth, pVars, nVars );
|
||||
}
|
||||
Dua_DsdWriteStop( p );
|
||||
return p->pOutput;
|
||||
|
|
|
|||
Loading…
Reference in New Issue