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/**CFile****************************************************************
FileName [extraUtilMaj.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [extra]
Synopsis [Path enumeration.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - June 20, 2005.]
Revision [$Id: extraUtilMaj.c,v 1.0 2003/02/01 00:00:00 alanmi Exp $]
***********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "misc/vec/vec.h"
#include "misc/vec/vecMem.h"
#include "misc/extra/extra.h"
#include "misc/util/utilTruth.h"
#include "opt/dau/dau.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
typedef struct Gem_Man_t_ Gem_Man_t;
typedef struct Gem_Obj_t_ Gem_Obj_t;
struct Gem_Man_t_
{
int nVars; // max variable count
int nWords; // truth tabel word count
int nObjsAlloc; // allocated objects
int nObjs; // used objects
Gem_Obj_t * pObjs; // function objects
Vec_Mem_t * vTtMem; // truth table memory and hash table
word ** pTtElems; // elementary truth tables
int fVerbose;
};
struct Gem_Obj_t_ // 8 bytes
{
unsigned nVars : 4; // variable count
unsigned nNodes : 4; // node count
unsigned History : 8; // (i < j) ? {vi, vj} : {vi, 0}
unsigned Groups : 16; // mask with last vars in each symmetric group
int Predec; // predecessor
};
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Gem_PrintNode( Gem_Man_t * p, int f, char * pLabel, int fUpdate )
{
Gem_Obj_t * pObj = p->pObjs + f;
int GroupsMod = pObj->Groups;
if ( !p->fVerbose )
return;
printf( "Node %6d : %s Pred = %6d Vars = %d Nodes = %d History = %d%d Profile: ",
f, pLabel, pObj->Predec, pObj->nVars, pObj->nNodes, pObj->History & 0xF, pObj->History >> 4 );
Extra_PrintBinary2( stdout, (unsigned*)&GroupsMod, p->nVars ); printf("%s\n", fUpdate?" *":"");
}
Gem_Man_t * Gem_ManAlloc( int nVars, int fVerbose )
{
Gem_Man_t * p;
assert( nVars <= 16 );
p = ABC_CALLOC( Gem_Man_t, 1 );
p->nVars = nVars;
p->nWords = Abc_TtWordNum( nVars );
p->nObjsAlloc = 10000000;
p->nObjs = 2;
p->pObjs = ABC_CALLOC( Gem_Obj_t, p->nObjsAlloc );
p->pObjs[1].nVars = p->pObjs[1].Groups = 1; // buffer
p->vTtMem = Vec_MemAllocForTT( nVars, 0 );
p->pTtElems = (word **)Extra_ArrayAlloc( nVars + 4, p->nWords, sizeof(word) );
p->fVerbose = fVerbose;
Abc_TtElemInit( p->pTtElems, nVars );
Gem_PrintNode( p, 1, "Original", 0 );
return p;
}
int Gem_ManFree( Gem_Man_t * p )
{
Vec_MemHashFree( p->vTtMem );
Vec_MemFree( p->vTtMem );
ABC_FREE( p->pTtElems );
ABC_FREE( p->pObjs );
ABC_FREE( p );
return 1;
}
void Gem_ManRealloc( Gem_Man_t * p )
{
int nObjNew = Abc_MinInt( 2 * p->nObjsAlloc, 0x7FFFFFFF );
assert( p->nObjs == p->nObjsAlloc );
if ( p->nObjs == 0x7FFFFFFF )
printf( "Hard limit on the number of nodes (0x7FFFFFFF) is reached. Quitting...\n" ), exit(1);
assert( p->nObjs < nObjNew );
printf("Extending object storage: %d -> %d.\n", p->nObjsAlloc, nObjNew );
p->pObjs = ABC_REALLOC( Gem_Obj_t, p->pObjs, nObjNew );
memset( p->pObjs + p->nObjsAlloc, 0, sizeof(Gem_Obj_t) * (nObjNew - p->nObjsAlloc) );
p->nObjsAlloc = nObjNew;
}
/**Function*************************************************************
Synopsis [Derive groups using symmetry info.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Gem_GroupsDerive( word * pTruth, int nVars, word * pCof0, word * pCof1 )
{
int v, Res = 1 << (nVars-1);
for ( v = 0; v < nVars-1; v++ )
if ( !Abc_TtVarsAreSymmetric(pTruth, nVars, v, v+1, pCof0, pCof1) )
Res |= (1 << v);
return Res;
}
/**Function*************************************************************
Synopsis [Extends function f by replacing var i with a new gate.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Gem_GroupVarRemove( int Groups, int i ) // remove i-th var
{
int Mask = i ? Abc_InfoMask( i ) : 0;
assert( i >= 0 );
assert( (Groups >> i) & 1 );
return (Groups & Mask) | ((Groups & ~Mask) >> 1);
}
int Gem_GroupVarsInsert1( int Groups, int i, int fGroup ) // insert one bit after i
{
int Mask = i+1 ? Abc_InfoMask( i+1 ) : 0;
assert( i+1 >= 0 );
assert( !fGroup || i == -1 || ((Groups >> i) & 1) );
assert( fGroup == 0 || fGroup == 1 );
return (Groups & Mask) | ((Groups & ~Mask) << 1) | (fGroup << (i+1));
}
int Gem_GroupVarsInsert3( int Groups, int i ) // insert group of 3 bits after i
{
int Mask = i+1 ? Abc_InfoMask( i+1 ) : 0;
assert( i+1 >= 0 );
assert( i == -1 || (Groups >> i) & 1 );
return (Groups & Mask) | ((Groups & ~Mask) << 3) | (0x4 << (i+1));
}
int Gem_GroupUnpack( int Groups, int * pVars )
{
int v, nGroups = 0;
for ( v = 0; Groups; v++, Groups >>= 1 )
if ( Groups & 1 )
pVars[nGroups++] = v;
return nGroups;
}
int Gem_FuncFindPlace( word * pTruth, int nWords, int Groups, word * pBest, int fOneVar )
{
int pLast[16], nGroups = Gem_GroupUnpack( Groups, pLast );
int g, v, Value, BestPlace = nGroups ? pLast[nGroups - 1] : -1;
assert( nGroups >= 0 );
Abc_TtCopy( pBest, pTruth, nWords, 0 );
for ( g = nGroups - 1; g >= 0; g-- )
{
int Limit = g ? pLast[g-1] : -1;
for ( v = pLast[g]; v > Limit; v-- )
{
Abc_TtSwapAdjacent( pTruth, nWords, v+0 );
if ( fOneVar )
continue;
Abc_TtSwapAdjacent( pTruth, nWords, v+1 );
Abc_TtSwapAdjacent( pTruth, nWords, v+2 );
}
Value = memcmp(pBest, pTruth, sizeof(word)*nWords);
if ( Value < 0 )
{
Abc_TtCopy( pBest, pTruth, nWords, 0 );
BestPlace = Limit;
}
}
return BestPlace;
}
void Gem_FuncExpand( Gem_Man_t * p, int f, int i )
{
Gem_Obj_t * pNew = p->pObjs + p->nObjs, * pObj = p->pObjs + f;
word * pTruth = Vec_MemReadEntry( p->vTtMem, f );
word * pResult = p->pTtElems[p->nVars];
word * pCofs[2] = { p->pTtElems[p->nVars+2], p->pTtElems[p->nVars+3] };
int v, iFunc;
char pCanonPermC[16];
assert( i < (int)pObj->nVars );
assert( (int)pObj->nVars + 2 <= p->nVars );
Abc_TtCopy( pResult, pTruth, p->nWords, 0 );
// move i variable to the end
for ( v = i; v < (int)pObj->nVars-1; v++ )
Abc_TtSwapAdjacent( pResult, p->nWords, v );
// create new symmetric group
assert( v == (int)pObj->nVars-1 );
Abc_TtCofactor0p( pCofs[0], pResult, p->nWords, v );
Abc_TtCofactor1p( pCofs[1], pResult, p->nWords, v );
Abc_TtMaj( pResult, p->pTtElems[v], p->pTtElems[v+1], p->pTtElems[v+2], p->nWords );
Abc_TtMux( pResult, pResult, pCofs[1], pCofs[0], p->nWords );
// canonicize
//Extra_PrintHex( stdout, (unsigned*)pResult, pObj->nVars + 2 ); printf("\n");
Abc_TtCanonicizePerm( pResult, pObj->nVars + 2, pCanonPermC );
Abc_TtStretch6( pResult, Abc_MaxInt(6, pObj->nVars+2), p->nVars );
//Extra_PrintHex( stdout, (unsigned*)pResult, pObj->nVars + 2 ); printf("\n\n");
iFunc = Vec_MemHashInsert( p->vTtMem, pResult );
if ( iFunc < p->nObjs )
return;
assert( iFunc == p->nObjs );
pNew->nVars = pObj->nVars + 2;
pNew->nNodes = pObj->nNodes + 1;
pNew->Groups = Gem_GroupsDerive( pResult, pNew->nVars, pCofs[0], pCofs[1] );
pNew->Predec = f;
pNew->History = i;
Gem_PrintNode( p, iFunc, "Expand ", 0 );
assert( p->nObjs < p->nObjsAlloc );
if ( ++p->nObjs == p->nObjsAlloc )
Gem_ManRealloc( p );
}
/**Function*************************************************************
Synopsis [Reduces function f by crossbaring variables i and j.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Gem_FuncCheckMajority( Gem_Man_t * p, int f )
{
Gem_Obj_t * pObj = p->pObjs + f;
word * pTruth = Vec_MemReadEntry( p->vTtMem, f );
int Polar = Abc_TtIsFullySymmetric( pTruth, pObj->nVars );
if ( Polar != -1 )
{
int nHalfVars = (pObj->nVars+1) >> 1;
int Mask = Abc_Tt6Mask( nHalfVars );
printf( "Found symmetric %d-variable function: ", pObj->nVars );
Extra_PrintBinary2( stdout, (unsigned *)&Polar, pObj->nVars + 1 );
printf( " " );
if ( (pObj->nVars & 1) && Polar == (Mask << nHalfVars) )
{
printf( "This is majority-%d.\n", pObj->nVars );
return 0;
}
printf( "\n" );
}
return 0;
}
int Gem_FuncReduce( Gem_Man_t * p, int f, int i, int j )
{
Gem_Obj_t * pNew = p->pObjs + p->nObjs, * pObj = p->pObjs + f;
word * pTruth = Vec_MemReadEntry( p->vTtMem, f );
word * pResult = p->pTtElems[p->nVars];
word * pCofs[2] = { p->pTtElems[p->nVars+2], p->pTtElems[p->nVars+3] };
int v, iFunc;
char pCanonPermC[16];
assert( i < j && j < 16 );
Abc_TtCopy( pResult, pTruth, p->nWords, 0 );
// move j variable to the end
for ( v = j; v < (int)pObj->nVars-1; v++ )
Abc_TtSwapAdjacent( pResult, p->nWords, v );
assert( v == (int)pObj->nVars-1 );
// move i variable to the end
for ( v = i; v < (int)pObj->nVars-2; v++ )
Abc_TtSwapAdjacent( pResult, p->nWords, v );
assert( v == (int)pObj->nVars-2 );
// create new variable
Abc_TtCofactor0p( pCofs[0], pResult, p->nWords, v+1 );
Abc_TtCofactor1p( pCofs[1], pResult, p->nWords, v+1 );
Abc_TtCofactor0( pCofs[0], p->nWords, v );
Abc_TtCofactor1( pCofs[1], p->nWords, v );
Abc_TtMux( pResult, p->pTtElems[v], pCofs[1], pCofs[0], p->nWords );
// canonicize
//Extra_PrintHex( stdout, (unsigned*)pResult, pObj->nVars - 1 ); printf("\n");
Abc_TtCanonicizePerm( pResult, pObj->nVars - 1, pCanonPermC );
Abc_TtStretch6( pResult, Abc_MaxInt(6, pObj->nVars-1), p->nVars );
//Extra_PrintHex( stdout, (unsigned*)pResult, pObj->nVars - 1 ); printf("\n\n");
iFunc = Vec_MemHashInsert( p->vTtMem, pResult );
if ( iFunc < p->nObjs )
return 0;
assert( iFunc == p->nObjs );
pNew->nVars = pObj->nVars - 1;
pNew->nNodes = pObj->nNodes;
pNew->Groups = Gem_GroupsDerive( pResult, pNew->nVars, pCofs[0], pCofs[1] );
pNew->Predec = f;
pNew->History = (j << 4) | i;
Gem_PrintNode( p, iFunc, "Crossbar", 0 );
Gem_FuncCheckMajority( p, iFunc );
assert( p->nObjs < p->nObjsAlloc );
if ( ++p->nObjs == p->nObjsAlloc )
Gem_ManRealloc( p );
return 0;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Gem_Enumerate( int nVars, int fDump, int fVerbose )
{
abctime clk = Abc_Clock();
Gem_Man_t * p = Gem_ManAlloc( nVars, fVerbose );
int v, f, i, j, nObjsStop = 1;
for ( v = 1; v <= nVars-2; v++ )
{
// expand functions by adding a gate
int nObjsStopPrev = nObjsStop;
nObjsStop = p->nObjs;
printf( "Expanding var %2d (functions = %10d) ", v, p->nObjs );
Abc_PrintTime( 0, "Time", Abc_Clock() - clk );
for ( f = 0; f < nObjsStop; f++ )
if ( v == (int)p->pObjs[f].nVars || (v > (int)p->pObjs[f].nVars && f >= nObjsStopPrev) )
for ( i = 0; i < v; i++ )
if ( (int)p->pObjs[f].Groups & (1 << i) )
Gem_FuncExpand( p, f, i );
// reduce functions by adding a crossbar
printf( "Connecting var %2d (functions = %10d) ", v, p->nObjs );
Abc_PrintTime( 0, "Time", Abc_Clock() - clk );
for ( f = nObjsStop; f < p->nObjs; f++ )
for ( i = 0; i < (int)p->pObjs[f].nVars; i++ )
if ( (int)p->pObjs[f].Groups & (1 << i) )
for ( j = i+1; j < (int)p->pObjs[f].nVars; j++ )
if ( (int)p->pObjs[f].Groups & (1 << j) )
if ( Gem_FuncReduce( p, f, i, j ) )
return Gem_ManFree( p );
}
printf( "Finished (functions = %10d) ", p->nObjs );
Abc_PrintTime( 0, "Time", Abc_Clock() - clk );
if ( fDump ) Vec_MemDumpTruthTables( p->vTtMem, "enum", nVars );
Gem_ManFree( p );
return 0;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
