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/**CFile****************************************************************
FileName [ifDec.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [FPGA mapping based on priority cuts.]
Synopsis [Performs additional check.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - November 21, 2006.]
Revision [$Id: ifDec.c,v 1.00 2006/11/21 00:00:00 alanmi Exp $]
***********************************************************************/
#include "if.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
// the bit count for the first 256 integer numbers
static int BitCount8[256] = {
0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8
};
// variable swapping code
static word PMasks[5][3] = {
{ 0x9999999999999999, 0x2222222222222222, 0x4444444444444444 },
{ 0xC3C3C3C3C3C3C3C3, 0x0C0C0C0C0C0C0C0C, 0x3030303030303030 },
{ 0xF00FF00FF00FF00F, 0x00F000F000F000F0, 0x0F000F000F000F00 },
{ 0xFF0000FFFF0000FF, 0x0000FF000000FF00, 0x00FF000000FF0000 },
{ 0xFFFF00000000FFFF, 0x00000000FFFF0000, 0x0000FFFF00000000 }
};
// elementary truth tables
static word Truth6[6] = {
0xAAAAAAAAAAAAAAAA,
0xCCCCCCCCCCCCCCCC,
0xF0F0F0F0F0F0F0F0,
0xFF00FF00FF00FF00,
0xFFFF0000FFFF0000,
0xFFFFFFFF00000000
};
static word Truth7[7][2] = {
0xAAAAAAAAAAAAAAAA,0xAAAAAAAAAAAAAAAA,
0xCCCCCCCCCCCCCCCC,0xCCCCCCCCCCCCCCCC,
0xF0F0F0F0F0F0F0F0,0xF0F0F0F0F0F0F0F0,
0xFF00FF00FF00FF00,0xFF00FF00FF00FF00,
0xFFFF0000FFFF0000,0xFFFF0000FFFF0000,
0xFFFFFFFF00000000,0xFFFFFFFF00000000,
0xFFFFFFFFFFFFFFFF,0x0000000000000000
};
extern void Kit_DsdPrintFromTruth( unsigned * pTruth, int nVars );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
// verification for 6-input function
static word If_Dec6ComposeLut4( int t, word f[4] )
{
int m, v;
word c, r = 0;
for ( m = 0; m < 16; m++ )
{
c = ~0;
for ( v = 0; v < 4; v++ )
c &= ((m >> v) & 1) ? f[v] : ~f[v];
r |= c;
}
return r;
}
static void If_Dec6Verify( word t, word z )
{
word f[4];
int i, v;
for ( i = 0; i < 4; i++ )
{
v = (z >> (16+(i<<2))) & 7;
f[i] = (v == 7) ? 0 : Truth6[v];
}
f[0] = If_Dec6ComposeLut4( (int)(z & 0xffff), f );
for ( i = 0; i < 3; i++ )
{
v = (z >> (48+(i<<2))) & 7;
f[i+1] = (v == 7) ? 0 : Truth6[v];
}
f[0] = If_Dec6ComposeLut4( (int)((z >> 32) & 0xffff), f );
if ( f[0] != t )
printf( "Verification failed!\n" );
}
// verification for 7-input function
static void If_Dec7ComposeLut4( int t, word f[4][2], word r[2] )
{
int m, v;
word c[2];
r[0] = r[1] = 0;
for ( m = 0; m < 16; m++ )
{
c[0] = c[1] = ~0;
for ( v = 0; v < 4; v++ )
{
c[0] &= ((m >> v) & 1) ? f[v][0] : ~f[v][0];
c[1] &= ((m >> v) & 1) ? f[v][1] : ~f[v][1];
}
r[0] |= c[0];
r[1] |= c[1];
}
}
static void If_Dec7Verify( word t[2], word z )
{
word f[4][2], r[2];
int i, v;
for ( i = 0; i < 4; i++ )
{
v = (z >> (16+(i<<2))) & 7;
f[i][0] = Truth7[v][0];
f[i][1] = Truth7[v][1];
}
If_Dec7ComposeLut4( (int)(z & 0xffff), f, r );
f[0][0] = r[0];
f[0][1] = r[1];
for ( i = 0; i < 3; i++ )
{
v = (z >> (48+(i<<2))) & 7;
f[i+1][0] = Truth7[v][0];
f[i+1][1] = Truth7[v][1];
}
If_Dec7ComposeLut4( (int)((z >> 32) & 0xffff), f, r );
if ( r[0] != t[0] || r[1] != t[1] )
printf( "Verification failed!\n" );
}
// count the number of unique cofactors
static inline int If_Dec6CofCount2( word t )
{
int i, Mask = 0;
for ( i = 0; i < 16; i++ )
Mask |= (1 << ((t >> (i<<2)) & 15));
return BitCount8[((unsigned char*)&Mask)[0]] + BitCount8[((unsigned char*)&Mask)[1]];
}
// count the number of unique cofactors (up to 3)
static inline int If_Dec7CofCount3( word t[2] )
{
unsigned char * pTruth = (unsigned char *)t;
int i, iCof2 = 0;
for ( i = 1; i < 16; i++ )
{
if ( pTruth[i] == pTruth[0] )
continue;
if ( iCof2 == 0 )
iCof2 = i;
else if ( pTruth[i] != pTruth[iCof2] )
return 3;
}
assert( iCof2 );
return 2;
}
// permute 6-input function
static inline word If_Dec6SwapAdjacent( word t, int v )
{
assert( v < 5 );
return (t & PMasks[v][0]) | ((t & PMasks[v][1]) << (1 << v)) | ((t & PMasks[v][2]) >> (1 << v));
}
static inline word If_Dec6MoveTo( word t, int v, int p, int Pla2Var[6], int Var2Pla[6] )
{
int iPlace0, iPlace1;
assert( Var2Pla[v] >= p );
while ( Var2Pla[v] != p )
{
iPlace0 = Var2Pla[v]-1;
iPlace1 = Var2Pla[v];
t = If_Dec6SwapAdjacent( t, iPlace0 );
Var2Pla[Pla2Var[iPlace0]]++;
Var2Pla[Pla2Var[iPlace1]]--;
Pla2Var[iPlace0] ^= Pla2Var[iPlace1];
Pla2Var[iPlace1] ^= Pla2Var[iPlace0];
Pla2Var[iPlace0] ^= Pla2Var[iPlace1];
}
assert( Pla2Var[p] == v );
return t;
}
// permute 7-input function
static inline void If_Dec7SwapAdjacent( word t[2], int v )
{
if ( v == 5 )
{
unsigned Temp = (t[0] >> 32);
t[0] = (t[0] & 0xFFFFFFFF) | ((t[1] & 0xFFFFFFFF) << 32);
t[1] ^= (t[1] & 0xFFFFFFFF) ^ Temp;
return;
}
assert( v < 5 );
t[0] = If_Dec6SwapAdjacent( t[0], v );
t[1] = If_Dec6SwapAdjacent( t[1], v );
}
static inline void If_Dec7MoveTo( word t[2], int v, int p, int Pla2Var[7], int Var2Pla[7] )
{
int iPlace0, iPlace1;
assert( Var2Pla[v] >= p );
while ( Var2Pla[v] != p )
{
iPlace0 = Var2Pla[v]-1;
iPlace1 = Var2Pla[v];
If_Dec7SwapAdjacent( t, iPlace0 );
Var2Pla[Pla2Var[iPlace0]]++;
Var2Pla[Pla2Var[iPlace1]]--;
Pla2Var[iPlace0] ^= Pla2Var[iPlace1];
Pla2Var[iPlace1] ^= Pla2Var[iPlace0];
Pla2Var[iPlace0] ^= Pla2Var[iPlace1];
}
assert( Pla2Var[p] == v );
}
// derives decomposition
static word If_Dec6DeriveDisjoint( word t, int Pla2Var[6], int Var2Pla[6] )
{
word z = 1;
// If_Dec6Verify( t, z );
return z;
}
static word If_Dec6DeriveNonDisjoint( word t, word c0, word c1, int s, int Pla2Var[6], int Var2Pla[6] )
{
word z = 1;
// If_Dec6Verify( t, z );
return z;
}
static word If_Dec7DeriveDisjoint( word t[2], int Pla2Var[7], int Var2Pla[7] )
{
word z = 1;
// If_Dec7Verify( t, z );
return z;
}
static inline int If_Dec6CountOnes( word t )
{
t = (t & 0x5555555555555555) + ((t>> 1) & 0x5555555555555555);
t = (t & 0x3333333333333333) + ((t>> 2) & 0x3333333333333333);
t = (t & 0x0F0F0F0F0F0F0F0F) + ((t>> 4) & 0x0F0F0F0F0F0F0F0F);
t = (t & 0x00FF00FF00FF00FF) + ((t>> 8) & 0x00FF00FF00FF00FF);
t = (t & 0x0000FFFF0000FFFF) + ((t>>16) & 0x0000FFFF0000FFFF);
return (t & 0x00000000FFFFFFFF) + (t>>32);
}
static inline int If_Dec6HasVar( word t, int v )
{
return ((t & Truth6[v]) >> (1<<v)) != (t & ~Truth6[v]);
}
static inline void If_DecVerifyPerm( int Pla2Var[6], int Var2Pla[6] )
{
int i;
for ( i = 0; i < 6; i++ )
assert( Pla2Var[Var2Pla[i]] == i );
}
static inline word If_Dec6Cofactor( word t, int iVar, int fCof1 )
{
assert( iVar >= 0 && iVar < 6 );
if ( fCof1 )
return (t & Truth6[iVar]) | ((t & Truth6[iVar]) >> (1<<iVar));
else
return (t &~Truth6[iVar]) | ((t &~Truth6[iVar]) << (1<<iVar));
}
static word If_Dec6Perform( word t )
{
int i, v, u, x, Count, Pla2Var[6], Var2Pla[6];
int fFound = 0;
// if ( If_Dec6CountOnes(t) == 1 )
// return 1;
// start arrays
for ( i = 0; i < 6; i++ )
{
assert( If_Dec6HasVar( t, i ) );
Pla2Var[i] = Var2Pla[i] = i;
}
// generate permutations
i = 0;
for ( v = 0; v < 6; v++ )
for ( u = v+1; u < 6; u++, i++ )
{
t = If_Dec6MoveTo( t, v, 0, Pla2Var, Var2Pla );
t = If_Dec6MoveTo( t, u, 1, Pla2Var, Var2Pla );
// If_DecVerifyPerm( Pla2Var, Var2Pla );
Count = If_Dec6CofCount2( t );
assert( Count > 1 );
if ( Count == 2 )
return If_Dec6DeriveDisjoint( t, Pla2Var, Var2Pla );
// check non-disjoint decomposition
if ( !fFound && (Count == 3 || Count == 4) )
{
for ( x = 0; x < 4; x++ )
{
word c0 = If_Dec6Cofactor( t, Pla2Var[x+2], 0 );
word c1 = If_Dec6Cofactor( t, Pla2Var[x+2], 1 );
if ( If_Dec6CofCount2( c0 ) <= 2 && If_Dec6CofCount2( c1 ) <= 2 )
{
fFound = 1;
break;
// return If_Dec6DeriveNonDisjoint( t, c0, c1, x+2, Pla2Var, Var2Pla );
}
}
}
}
assert( i == 15 );
return fFound;
}
static word If_Dec7Perform( word t0[2] )
{
word t[2] = {t0[0], t0[1]};
int i, v, u, y, Pla2Var[7], Var2Pla[7];
// start arrays
for ( i = 0; i < 7; i++ )
{
if ( i < 6 )
assert( If_Dec6HasVar( t[0], i ) || If_Dec6HasVar( t[1], i ) );
else
assert( t[0] != t[1] );
Pla2Var[i] = Var2Pla[i] = i;
}
// generate permutations
for ( v = 0; v < 7; v++ )
for ( u = v+1; u < 7; u++ )
for ( y = u+1; y < 7; y++ )
{
If_Dec7MoveTo( t, v, 0, Pla2Var, Var2Pla );
If_Dec7MoveTo( t, u, 1, Pla2Var, Var2Pla );
If_Dec7MoveTo( t, y, 2, Pla2Var, Var2Pla );
// If_DecVerifyPerm( Pla2Var, Var2Pla );
if ( If_Dec7CofCount3( t ) == 2 )
return If_Dec7DeriveDisjoint( t, Pla2Var, Var2Pla );
}
return 0;
}
/**Function*************************************************************
Synopsis [Performs additional check.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int If_CutPerformCheckInt( unsigned * pTruth, int nVars, int nLeaves )
{
if ( nLeaves < 6 )
return 1;
if ( nLeaves == 6 )
{
word t = ((word *)pTruth)[0];
return If_Dec6Perform( t ) != 0;
}
if ( nLeaves == 7 )
{
word t[2];
t[0] = ((word *)pTruth)[0];
t[1] = ((word *)pTruth)[1];
return If_Dec7Perform( t ) != 0;
}
assert( 0 );
return 0;
}
int If_CutPerformCheck( unsigned * pTruth, int nVars, int nLeaves )
{
int RetValue = If_CutPerformCheckInt( pTruth, nVars, nLeaves );
/*
// if ( nLeaves == 6 || nLeaves == 7 )
if ( nLeaves == 7 )
{
if ( RetValue == 0 )
{
printf( "%d ", RetValue );
Kit_DsdPrintFromTruth( pTruth, nLeaves );
printf( "\n" );
If_CutPerformCheckInt( pTruth, nVars, nLeaves );
}
}
*/
return RetValue;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|