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/**CFile****************************************************************
FileName [ivyIsop.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [And-Inverter Graph package.]
Synopsis [Computing irredundant SOP using truth table.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - May 11, 2006.]
Revision [$Id: ivyIsop.c,v 1.00 2006/05/11 00:00:00 alanmi Exp $]
***********************************************************************/
#include "ivy.h"
#include "mem.h"
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
typedef struct Ivy_Sop_t_ Ivy_Sop_t;
struct Ivy_Sop_t_
{
unsigned * pCubes;
int nCubes;
};
static Mem_Flex_t * s_Man = NULL;
static unsigned * Ivy_TruthIsop_rec( unsigned * puOn, unsigned * puOnDc, int nVars, Ivy_Sop_t * pcRes );
static unsigned Ivy_TruthIsop5_rec( unsigned uOn, unsigned uOnDc, int nVars, Ivy_Sop_t * pcRes );
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Deallocates memory used for computing ISOPs from TTs.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Ivy_TruthManStop()
{
Mem_FlexStop( s_Man, 0 );
s_Man = NULL;
}
/**Function*************************************************************
Synopsis [Computes ISOP from TT.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Ivy_TruthIsopOne( unsigned * puTruth, int nVars, Vec_Int_t * vCover )
{
Ivy_Sop_t cRes, * pcRes = &cRes;
unsigned * pResult;
int i;
assert( nVars >= 0 && nVars < 16 );
// if nVars < 5, make sure it does not depend on those vars
for ( i = nVars; i < 5; i++ )
assert( !Extra_TruthVarInSupport(puTruth, 5, i) );
// prepare memory manager
if ( s_Man == NULL )
s_Man = Mem_FlexStart();
else
Mem_FlexRestart( s_Man );
// compute ISOP
pResult = Ivy_TruthIsop_rec( puTruth, puTruth, nVars, pcRes );
// Extra_PrintBinary( stdout, puTruth, 1 << nVars ); printf( "\n" );
// Extra_PrintBinary( stdout, pResult, 1 << nVars ); printf( "\n" );
assert( Extra_TruthIsEqual( puTruth, pResult, nVars ) );
//printf( "%d ", Mem_FlexReadMemUsage(s_Man) );
//printf( "%d ", pcRes->nCubes );
// copy the truth table
Vec_IntClear( vCover );
for ( i = 0; i < pcRes->nCubes; i++ )
Vec_IntPush( vCover, pcRes->pCubes[i] );
return 0;
}
/**Function*************************************************************
Synopsis [Computes ISOP from TT.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Ivy_TruthIsop( unsigned * puTruth, int nVars, Vec_Int_t * vCover )
{
Ivy_Sop_t cRes, * pcRes = &cRes;
unsigned * pResult;
int i;
assert( nVars >= 0 && nVars < 16 );
// if nVars < 5, make sure it does not depend on those vars
for ( i = nVars; i < 5; i++ )
assert( !Extra_TruthVarInSupport(puTruth, 5, i) );
// prepare memory manager
if ( s_Man == NULL )
s_Man = Mem_FlexStart();
else
Mem_FlexRestart( s_Man );
// compute ISOP
pResult = Ivy_TruthIsop_rec( puTruth, puTruth, nVars, pcRes );
// Extra_PrintBinary( stdout, puTruth, 1 << nVars ); printf( "\n" );
// Extra_PrintBinary( stdout, pResult, 1 << nVars ); printf( "\n" );
assert( Extra_TruthIsEqual( puTruth, pResult, nVars ) );
//printf( "%d ", Mem_FlexReadMemUsage(s_Man) );
//printf( "%d ", pcRes->nCubes );
// copy the truth table
Vec_IntClear( vCover );
for ( i = 0; i < pcRes->nCubes; i++ )
Vec_IntPush( vCover, pcRes->pCubes[i] );
// try other polarity
Mem_FlexRestart( s_Man );
Extra_TruthNot( puTruth, puTruth, nVars );
pResult = Ivy_TruthIsop_rec( puTruth, puTruth, nVars, pcRes );
assert( Extra_TruthIsEqual( puTruth, pResult, nVars ) );
Extra_TruthNot( puTruth, puTruth, nVars );
if ( Vec_IntSize(vCover) < pcRes->nCubes )
return 0;
// copy the truth table
Vec_IntClear( vCover );
for ( i = 0; i < pcRes->nCubes; i++ )
Vec_IntPush( vCover, pcRes->pCubes[i] );
return 1;
}
/**Function*************************************************************
Synopsis [Computes ISOP 6 variables or more.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
unsigned * Ivy_TruthIsop_rec( unsigned * puOn, unsigned * puOnDc, int nVars, Ivy_Sop_t * pcRes )
{
Ivy_Sop_t cRes0, cRes1, cRes2;
Ivy_Sop_t * pcRes0 = &cRes0, * pcRes1 = &cRes1, * pcRes2 = &cRes2;
unsigned * puRes0, * puRes1, * puRes2;
unsigned * puOn0, * puOn1, * puOnDc0, * puOnDc1, * pTemp, * pTemp0, * pTemp1;
int i, k, Var, nWords, nWordsAll;
assert( Extra_TruthIsImply( puOn, puOnDc, nVars ) );
// allocate room for the resulting truth table
nWordsAll = Extra_TruthWordNum( nVars );
pTemp = (unsigned *)Mem_FlexEntryFetch( s_Man, 4 * nWordsAll );
// check for constants
if ( Extra_TruthIsConst0( puOn, nVars ) )
{
pcRes->nCubes = 0;
pcRes->pCubes = NULL;
Extra_TruthClear( pTemp, nVars );
return pTemp;
}
if ( Extra_TruthIsConst1( puOnDc, nVars ) )
{
pcRes->nCubes = 1;
pcRes->pCubes = (unsigned *)Mem_FlexEntryFetch( s_Man, 4 );
pcRes->pCubes[0] = 0;
Extra_TruthFill( pTemp, nVars );
return pTemp;
}
assert( nVars > 0 );
// find the topmost var
for ( Var = nVars-1; Var >= 0; Var-- )
if ( Extra_TruthVarInSupport( puOn, nVars, Var ) ||
Extra_TruthVarInSupport( puOnDc, nVars, Var ) )
break;
assert( Var >= 0 );
// consider a simple case when one-word computation can be used
if ( Var < 5 )
{
unsigned uRes = Ivy_TruthIsop5_rec( puOn[0], puOnDc[0], Var+1, pcRes );
for ( i = 0; i < nWordsAll; i++ )
pTemp[i] = uRes;
return pTemp;
}
assert( Var >= 5 );
nWords = Extra_TruthWordNum( Var );
// cofactor
puOn0 = puOn; puOn1 = puOn + nWords;
puOnDc0 = puOnDc; puOnDc1 = puOnDc + nWords;
pTemp0 = pTemp; pTemp1 = pTemp + nWords;
// solve for cofactors
Extra_TruthSharp( pTemp0, puOn0, puOnDc1, Var );
puRes0 = Ivy_TruthIsop_rec( pTemp0, puOnDc0, Var, pcRes0 );
Extra_TruthSharp( pTemp1, puOn1, puOnDc0, Var );
puRes1 = Ivy_TruthIsop_rec( pTemp1, puOnDc1, Var, pcRes1 );
Extra_TruthSharp( pTemp0, puOn0, puRes0, Var );
Extra_TruthSharp( pTemp1, puOn1, puRes1, Var );
Extra_TruthOr( pTemp0, pTemp0, pTemp1, Var );
Extra_TruthAnd( pTemp1, puOnDc0, puOnDc1, Var );
puRes2 = Ivy_TruthIsop_rec( pTemp0, pTemp1, Var, pcRes2 );
// create the resulting cover
pcRes->nCubes = pcRes0->nCubes + pcRes1->nCubes + pcRes2->nCubes;
pcRes->pCubes = (unsigned *)Mem_FlexEntryFetch( s_Man, 4 * pcRes->nCubes );
k = 0;
for ( i = 0; i < pcRes0->nCubes; i++ )
pcRes->pCubes[k++] = pcRes0->pCubes[i] | (1 << ((Var<<1)+1));
for ( i = 0; i < pcRes1->nCubes; i++ )
pcRes->pCubes[k++] = pcRes1->pCubes[i] | (1 << ((Var<<1)+0));
for ( i = 0; i < pcRes2->nCubes; i++ )
pcRes->pCubes[k++] = pcRes2->pCubes[i];
assert( k == pcRes->nCubes );
// create the resulting truth table
Extra_TruthOr( pTemp0, puRes0, puRes2, Var );
Extra_TruthOr( pTemp1, puRes1, puRes2, Var );
// copy the table if needed
nWords <<= 1;
for ( i = 1; i < nWordsAll/nWords; i++ )
for ( k = 0; k < nWords; k++ )
pTemp[i*nWords + k] = pTemp[k];
// verify in the end
// assert( Extra_TruthIsImply( puOn, pTemp, nVars ) );
// assert( Extra_TruthIsImply( pTemp, puOnDc, nVars ) );
return pTemp;
}
/**Function*************************************************************
Synopsis [Computes ISOP for 5 variables or less.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
unsigned Ivy_TruthIsop5_rec( unsigned uOn, unsigned uOnDc, int nVars, Ivy_Sop_t * pcRes )
{
unsigned uMasks[5] = { 0xAAAAAAAA, 0xCCCCCCCC, 0xF0F0F0F0, 0xFF00FF00, 0xFFFF0000 };
Ivy_Sop_t cRes0, cRes1, cRes2;
Ivy_Sop_t * pcRes0 = &cRes0, * pcRes1 = &cRes1, * pcRes2 = &cRes2;
unsigned uOn0, uOn1, uOnDc0, uOnDc1, uRes0, uRes1, uRes2;
int i, k, Var;
assert( nVars <= 5 );
assert( (uOn & ~uOnDc) == 0 );
if ( uOn == 0 )
{
pcRes->nCubes = 0;
pcRes->pCubes = NULL;
return 0;
}
if ( uOnDc == 0xFFFFFFFF )
{
pcRes->nCubes = 1;
pcRes->pCubes = (unsigned *)Mem_FlexEntryFetch( s_Man, 4 );
pcRes->pCubes[0] = 0;
return 0xFFFFFFFF;
}
assert( nVars > 0 );
// find the topmost var
for ( Var = nVars-1; Var >= 0; Var-- )
if ( Extra_TruthVarInSupport( &uOn, 5, Var ) ||
Extra_TruthVarInSupport( &uOnDc, 5, Var ) )
break;
assert( Var >= 0 );
// cofactor
uOn0 = uOn1 = uOn;
uOnDc0 = uOnDc1 = uOnDc;
Extra_TruthCofactor0( &uOn0, Var + 1, Var );
Extra_TruthCofactor1( &uOn1, Var + 1, Var );
Extra_TruthCofactor0( &uOnDc0, Var + 1, Var );
Extra_TruthCofactor1( &uOnDc1, Var + 1, Var );
// solve for cofactors
uRes0 = Ivy_TruthIsop5_rec( uOn0 & ~uOnDc1, uOnDc0, Var, pcRes0 );
uRes1 = Ivy_TruthIsop5_rec( uOn1 & ~uOnDc0, uOnDc1, Var, pcRes1 );
uRes2 = Ivy_TruthIsop5_rec( (uOn0 & ~uRes0) | (uOn1 & ~uRes1), uOnDc0 & uOnDc1, Var, pcRes2 );
// create the resulting cover
pcRes->nCubes = pcRes0->nCubes + pcRes1->nCubes + pcRes2->nCubes;
pcRes->pCubes = (unsigned *)Mem_FlexEntryFetch( s_Man, 4 * pcRes->nCubes );
k = 0;
for ( i = 0; i < pcRes0->nCubes; i++ )
pcRes->pCubes[k++] = pcRes0->pCubes[i] | (1 << ((Var<<1)+1));
for ( i = 0; i < pcRes1->nCubes; i++ )
pcRes->pCubes[k++] = pcRes1->pCubes[i] | (1 << ((Var<<1)+0));
for ( i = 0; i < pcRes2->nCubes; i++ )
pcRes->pCubes[k++] = pcRes2->pCubes[i];
assert( k == pcRes->nCubes );
// derive the final truth table
uRes2 |= (uRes0 & ~uMasks[Var]) | (uRes1 & uMasks[Var]);
// assert( (uOn & ~uRes2) == 0 );
// assert( (uRes2 & ~uOnDc) == 0 );
return uRes2;
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
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