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/**CFile****************************************************************
FileName [kitSop.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [Computation kit.]
Synopsis [Procedures involving SOPs.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - Dec 6, 2006.]
Revision [$Id: kitSop.c,v 1.00 2006/12/06 00:00:00 alanmi Exp $]
***********************************************************************/
#include "kit.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis [Creates SOP from the cube array.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopCreate( Kit_Sop_t * cResult, Vec_Int_t * vInput, int nVars, Vec_Int_t * vMemory )
{
unsigned uCube;
int i;
// start the cover
cResult->nCubes = 0;
cResult->pCubes = Vec_IntFetch( vMemory, Vec_IntSize(vInput) );
// add the cubes
Vec_IntForEachEntry( vInput, uCube, i )
Kit_SopPushCube( cResult, uCube );
}
/**Function*************************************************************
Synopsis [Creates SOP from the cube array.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopCreateInverse( Kit_Sop_t * cResult, Vec_Int_t * vInput, int nLits, Vec_Int_t * vMemory )
{
unsigned uCube, uMask = 0;
int i, nCubes = Vec_IntSize(vInput);
// start the cover
cResult->nCubes = 0;
cResult->pCubes = Vec_IntFetch( vMemory, nCubes );
// add the cubes
// Vec_IntForEachEntry( vInput, uCube, i )
for ( i = 0; i < nCubes; i++ )
{
uCube = Vec_IntEntry( vInput, i );
uMask = ((uCube | (uCube >> 1)) & 0x55555555);
uMask |= (uMask << 1);
Kit_SopPushCube( cResult, uCube ^ uMask );
}
}
/**Function*************************************************************
Synopsis [Duplicates SOP.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopDup( Kit_Sop_t * cResult, Kit_Sop_t * cSop, Vec_Int_t * vMemory )
{
unsigned uCube;
int i;
// start the cover
cResult->nCubes = 0;
cResult->pCubes = Vec_IntFetch( vMemory, Kit_SopCubeNum(cSop) );
// add the cubes
Kit_SopForEachCube( cSop, uCube, i )
Kit_SopPushCube( cResult, uCube );
}
/**Function*************************************************************
Synopsis [Derives the quotient of division by literal.]
Description [Reduces the cover to be equal to the result of
division of the given cover by the literal.]
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopDivideByLiteralQuo( Kit_Sop_t * cSop, int iLit )
{
unsigned uCube;
int i, k = 0;
Kit_SopForEachCube( cSop, uCube, i )
{
if ( Kit_CubeHasLit(uCube, iLit) )
Kit_SopWriteCube( cSop, Kit_CubeRemLit(uCube, iLit), k++ );
}
Kit_SopShrink( cSop, k );
}
/**Function*************************************************************
Synopsis [Divides cover by one cube.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopDivideByCube( Kit_Sop_t * cSop, Kit_Sop_t * cDiv, Kit_Sop_t * vQuo, Kit_Sop_t * vRem, Vec_Int_t * vMemory )
{
unsigned uCube, uDiv;
int i;
// get the only cube
assert( Kit_SopCubeNum(cDiv) == 1 );
uDiv = Kit_SopCube(cDiv, 0);
// allocate covers
vQuo->nCubes = 0;
vQuo->pCubes = Vec_IntFetch( vMemory, Kit_SopCubeNum(cSop) );
vRem->nCubes = 0;
vRem->pCubes = Vec_IntFetch( vMemory, Kit_SopCubeNum(cSop) );
// sort the cubes
Kit_SopForEachCube( cSop, uCube, i )
{
if ( Kit_CubeContains( uCube, uDiv ) )
Kit_SopPushCube( vQuo, Kit_CubeSharp(uCube, uDiv) );
else
Kit_SopPushCube( vRem, uCube );
}
}
/**Function*************************************************************
Synopsis [Divides cover by one cube.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopDivideInternal( Kit_Sop_t * cSop, Kit_Sop_t * cDiv, Kit_Sop_t * vQuo, Kit_Sop_t * vRem, Vec_Int_t * vMemory )
{
unsigned uCube, uDiv;
unsigned uCube2 = 0; // Suppress "might be used uninitialized"
unsigned uDiv2, uQuo;
int i, i2, k, k2, nCubesRem;
assert( Kit_SopCubeNum(cSop) >= Kit_SopCubeNum(cDiv) );
// consider special case
if ( Kit_SopCubeNum(cDiv) == 1 )
{
Kit_SopDivideByCube( cSop, cDiv, vQuo, vRem, vMemory );
return;
}
// allocate quotient
vQuo->nCubes = 0;
vQuo->pCubes = Vec_IntFetch( vMemory, Kit_SopCubeNum(cSop) / Kit_SopCubeNum(cDiv) );
// for each cube of the cover
// it either belongs to the quotient or to the remainder
Kit_SopForEachCube( cSop, uCube, i )
{
// skip taken cubes
if ( Kit_CubeIsMarked(uCube) )
continue;
// find a matching cube in the divisor
uDiv = ~0;
Kit_SopForEachCube( cDiv, uDiv, k )
if ( Kit_CubeContains( uCube, uDiv ) )
break;
// the cube is not found
if ( k == Kit_SopCubeNum(cDiv) )
continue;
// the quotient cube exists
uQuo = Kit_CubeSharp( uCube, uDiv );
// find corresponding cubes for other cubes of the divisor
uDiv2 = ~0;
Kit_SopForEachCube( cDiv, uDiv2, k2 )
{
if ( k2 == k )
continue;
// find a matching cube
Kit_SopForEachCube( cSop, uCube2, i2 )
{
// skip taken cubes
if ( Kit_CubeIsMarked(uCube2) )
continue;
// check if the cube can be used
if ( Kit_CubeContains( uCube2, uDiv2 ) && uQuo == Kit_CubeSharp( uCube2, uDiv2 ) )
break;
}
// the case when the cube is not found
if ( i2 == Kit_SopCubeNum(cSop) )
break;
}
// we did not find some cubes - continue looking at other cubes
if ( k2 != Kit_SopCubeNum(cDiv) )
continue;
// we found all cubes - add the quotient cube
Kit_SopPushCube( vQuo, uQuo );
// mark the first cube
Kit_SopWriteCube( cSop, Kit_CubeMark(uCube), i );
// mark other cubes that have this quotient
Kit_SopForEachCube( cDiv, uDiv2, k2 )
{
if ( k2 == k )
continue;
// find a matching cube
Kit_SopForEachCube( cSop, uCube2, i2 )
{
// skip taken cubes
if ( Kit_CubeIsMarked(uCube2) )
continue;
// check if the cube can be used
if ( Kit_CubeContains( uCube2, uDiv2 ) && uQuo == Kit_CubeSharp( uCube2, uDiv2 ) )
break;
}
assert( i2 < Kit_SopCubeNum(cSop) );
// the cube is found, mark it
// (later we will add all unmarked cubes to the remainder)
Kit_SopWriteCube( cSop, Kit_CubeMark(uCube2), i2 );
}
}
// determine the number of cubes in the remainder
nCubesRem = Kit_SopCubeNum(cSop) - Kit_SopCubeNum(vQuo) * Kit_SopCubeNum(cDiv);
// allocate remainder
vRem->nCubes = 0;
vRem->pCubes = Vec_IntFetch( vMemory, nCubesRem );
// finally add the remaining unmarked cubes to the remainder
// and clean the marked cubes in the cover
Kit_SopForEachCube( cSop, uCube, i )
{
if ( !Kit_CubeIsMarked(uCube) )
{
Kit_SopPushCube( vRem, uCube );
continue;
}
Kit_SopWriteCube( cSop, Kit_CubeUnmark(uCube), i );
}
assert( nCubesRem == Kit_SopCubeNum(vRem) );
}
/**Function*************************************************************
Synopsis [Returns the common cube.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline unsigned Kit_SopCommonCube( Kit_Sop_t * cSop )
{
unsigned uMask, uCube;
int i;
uMask = ~(unsigned)0;
Kit_SopForEachCube( cSop, uCube, i )
uMask &= uCube;
return uMask;
}
/**Function*************************************************************
Synopsis [Makes the cover cube-free.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopMakeCubeFree( Kit_Sop_t * cSop )
{
unsigned uMask, uCube;
int i;
uMask = Kit_SopCommonCube( cSop );
if ( uMask == 0 )
return;
// remove the common cube
Kit_SopForEachCube( cSop, uCube, i )
Kit_SopWriteCube( cSop, Kit_CubeSharp(uCube, uMask), i );
}
/**Function*************************************************************
Synopsis [Checks if the cover is cube-free.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Kit_SopIsCubeFree( Kit_Sop_t * cSop )
{
return Kit_SopCommonCube( cSop ) == 0;
}
/**Function*************************************************************
Synopsis [Creates SOP composes of the common cube of the given SOP.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopCommonCubeCover( Kit_Sop_t * cResult, Kit_Sop_t * cSop, Vec_Int_t * vMemory )
{
assert( Kit_SopCubeNum(cSop) > 0 );
cResult->nCubes = 0;
cResult->pCubes = Vec_IntFetch( vMemory, 1 );
Kit_SopPushCube( cResult, Kit_SopCommonCube(cSop) );
}
/**Function*************************************************************
Synopsis [Find any literal that occurs more than once.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Kit_SopAnyLiteral( Kit_Sop_t * cSop, int nLits )
{
unsigned uCube;
int i, k, nLitsCur;
// go through each literal
for ( i = 0; i < nLits; i++ )
{
// go through all the cubes
nLitsCur = 0;
Kit_SopForEachCube( cSop, uCube, k )
if ( Kit_CubeHasLit(uCube, i) )
nLitsCur++;
if ( nLitsCur > 1 )
return i;
}
return -1;
}
/**Function*************************************************************
Synopsis [Find the least often occurring literal.]
Description [Find the least often occurring literal among those
that occur more than once.]
SideEffects []
SeeAlso []
***********************************************************************/
int Kit_SopWorstLiteral( Kit_Sop_t * cSop, int nLits )
{
unsigned uCube;
int i, k, iMin, nLitsMin, nLitsCur;
int fUseFirst = 1;
// go through each literal
iMin = -1;
nLitsMin = 1000000;
for ( i = 0; i < nLits; i++ )
{
// go through all the cubes
nLitsCur = 0;
Kit_SopForEachCube( cSop, uCube, k )
if ( Kit_CubeHasLit(uCube, i) )
nLitsCur++;
// skip the literal that does not occur or occurs once
if ( nLitsCur < 2 )
continue;
// check if this is the best literal
if ( fUseFirst )
{
if ( nLitsMin > nLitsCur )
{
nLitsMin = nLitsCur;
iMin = i;
}
}
else
{
if ( nLitsMin >= nLitsCur )
{
nLitsMin = nLitsCur;
iMin = i;
}
}
}
if ( nLitsMin < 1000000 )
return iMin;
return -1;
}
/**Function*************************************************************
Synopsis [Find the least often occurring literal.]
Description [Find the least often occurring literal among those
that occur more than once.]
SideEffects []
SeeAlso []
***********************************************************************/
int Kit_SopBestLiteral( Kit_Sop_t * cSop, int nLits, unsigned uMask )
{
unsigned uCube;
int i, k, iMax, nLitsMax, nLitsCur;
int fUseFirst = 1;
// go through each literal
iMax = -1;
nLitsMax = -1;
for ( i = 0; i < nLits; i++ )
{
if ( !Kit_CubeHasLit(uMask, i) )
continue;
// go through all the cubes
nLitsCur = 0;
Kit_SopForEachCube( cSop, uCube, k )
if ( Kit_CubeHasLit(uCube, i) )
nLitsCur++;
// skip the literal that does not occur or occurs once
if ( nLitsCur < 2 )
continue;
// check if this is the best literal
if ( fUseFirst )
{
if ( nLitsMax < nLitsCur )
{
nLitsMax = nLitsCur;
iMax = i;
}
}
else
{
if ( nLitsMax <= nLitsCur )
{
nLitsMax = nLitsCur;
iMax = i;
}
}
}
if ( nLitsMax >= 0 )
return iMax;
return -1;
}
/**Function*************************************************************
Synopsis [Computes a level-zero kernel.]
Description [Modifies the cover to contain one level-zero kernel.]
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopDivisorZeroKernel_rec( Kit_Sop_t * cSop, int nLits )
{
int iLit;
// find any literal that occurs at least two times
iLit = Kit_SopWorstLiteral( cSop, nLits );
if ( iLit == -1 )
return;
// derive the cube-free quotient
Kit_SopDivideByLiteralQuo( cSop, iLit ); // the same cover
Kit_SopMakeCubeFree( cSop ); // the same cover
// call recursively
Kit_SopDivisorZeroKernel_rec( cSop, nLits ); // the same cover
}
/**Function*************************************************************
Synopsis [Computes the quick divisor of the cover.]
Description [Returns 0, if there is no divisor other than trivial.]
SideEffects []
SeeAlso []
***********************************************************************/
int Kit_SopDivisor( Kit_Sop_t * cResult, Kit_Sop_t * cSop, int nLits, Vec_Int_t * vMemory )
{
if ( Kit_SopCubeNum(cSop) <= 1 )
return 0;
if ( Kit_SopAnyLiteral( cSop, nLits ) == -1 )
return 0;
// duplicate the cover
Kit_SopDup( cResult, cSop, vMemory );
// perform the kerneling
Kit_SopDivisorZeroKernel_rec( cResult, nLits );
assert( Kit_SopCubeNum(cResult) > 0 );
return 1;
}
/**Function*************************************************************
Synopsis [Create the one-literal cover with the best literal from cSop.]
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Kit_SopBestLiteralCover( Kit_Sop_t * cResult, Kit_Sop_t * cSop, unsigned uCube, int nLits, Vec_Int_t * vMemory )
{
int iLitBest;
// get the best literal
iLitBest = Kit_SopBestLiteral( cSop, nLits, uCube );
// start the cover
cResult->nCubes = 0;
cResult->pCubes = Vec_IntFetch( vMemory, 1 );
// set the cube
Kit_SopPushCube( cResult, Kit_CubeSetLit(0, iLitBest) );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END
|
