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New AIG optimization package.

This commit is contained in:
Alan Mishchenko 2012-10-06 16:11:08 -07:00
parent 3d23bc8c57
commit dc9a22582a
1 changed files with 18 additions and 31 deletions
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49
src/opt/dau/dauDsd.c
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@ -38,8 +38,14 @@ static word s_Truth6[6] =
0xFFFFFFFF00000000
};
// ! = not; (a + b) = a and b; [a + b] = a xor b; <abc> = ITE( a, b, c )
/*
This code performs truth-table-based decomposition for 6-variable functions.
Representation of operations:
! = not;
(ab) = a and b;
[ab] = a xor b;
<abc> = ITE( a, b, c )
*/
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
@ -173,28 +179,6 @@ static inline word Dau_DsdVarPres( word t, int iVar )
assert( iVar >= 0 && iVar < 6 );
return (t & s_Truth6[iVar]) != ((t << (1<<iVar)) & s_Truth6[iVar]);
}
static inline int Dau_DsdPerformReplace2( char * pBuffer, int PosStart, int Pos, int Symb, char * pNext )
{
char * pTemp, * pStop = pTemp = pBuffer + Pos;
int i, Len = strlen(pNext);
do
{
for ( pTemp = pBuffer + Pos - 1; pTemp >= pBuffer + PosStart; pTemp[Len-1] = *pTemp, pTemp-- )
if ( pTemp < pStop && *pTemp == (char)Symb )
{
for ( i = 0; i < Len; i++ )
pTemp[i] = pNext[i];
Pos += Len - 1;
pStop = pTemp;
// check if there is symbol left
for ( ; pTemp >= pBuffer + PosStart; pTemp-- )
if ( *pTemp == (char)Symb )
break;
break;
}
} while ( pTemp >= pBuffer + PosStart );
return Pos;
}
static inline int Dau_DsdPerformReplace( char * pBuffer, int PosStart, int Pos, int Symb, char * pNext )
{
static char pTemp[DAU_MAX_STR+20];
@ -218,12 +202,13 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
int pVarsNew[6], nVarsNew, PosStart;
int v, u, vBest, CountBest;
assert( Pos < DAU_MAX_STR );
// copy remaining variables
// perform support minimization
nVarsNew = 0;
for ( v = 0; v < nVars; v++ )
if ( Dau_DsdVarPres( t, pVars[v] ) )
pVarsNew[ nVarsNew++ ] = pVars[v];
assert( nVarsNew > 0 );
// special case when function is a var
if ( nVarsNew == 1 )
{
if ( t == s_Truth6[ pVarsNew[0] ] )
@ -240,12 +225,13 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
assert( 0 );
return Pos;
}
// decompose on the output side
for ( v = 0; v < nVarsNew; v++ )
{
Cof0[v] = Dau_DsdCof0( t, pVarsNew[v] );
Cof1[v] = Dau_DsdCof1( t, pVarsNew[v] );
assert( Cof0[v] != Cof1[v] );
if ( Cof0[v] == 0 )
if ( Cof0[v] == 0 ) // ax
{
pBuffer[Pos++] = '(';
pBuffer[Pos++] = 'a' + pVarsNew[v];
@ -253,7 +239,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
pBuffer[Pos++] = ')';
return Pos;
}
if ( Cof0[v] == ~0 )
if ( Cof0[v] == ~0 ) // !(ax)
{
pBuffer[Pos++] = '!';
pBuffer[Pos++] = '(';
@ -262,7 +248,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
pBuffer[Pos++] = ')';
return Pos;
}
if ( Cof1[v] == 0 )
if ( Cof1[v] == 0 ) // !ax
{
pBuffer[Pos++] = '(';
pBuffer[Pos++] = '!';
@ -271,7 +257,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
pBuffer[Pos++] = ')';
return Pos;
}
if ( Cof1[v] == ~0 )
if ( Cof1[v] == ~0 ) // !(!ax)
{
pBuffer[Pos++] = '!';
pBuffer[Pos++] = '(';
@ -281,7 +267,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
pBuffer[Pos++] = ')';
return Pos;
}
if ( Cof0[v] == ~Cof1[v] )
if ( Cof0[v] == ~Cof1[v] ) // a^x
{
pBuffer[Pos++] = '[';
pBuffer[Pos++] = 'a' + pVarsNew[v];
@ -290,6 +276,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
return Pos;
}
}
// decompose on the input side
for ( v = 0; v < nVarsNew; v++ )
for ( u = v+1; u < nVarsNew; u++ )
{
@ -338,7 +325,7 @@ int Dau_DsdPerform_rec( word t, char * pBuffer, int Pos, int * pVars, int nVars
return Pos;
}
}
// look for MUX
// find best variable for MUX decomposition
vBest = -1;
CountBest = 10;
for ( v = 0; v < nVarsNew; v++ )