/**CFile****************************************************************
FileName [bmcMaj.c]
SystemName [ABC: Logic synthesis and verification system.]
PackageName [SAT-based bounded model checking.]
Synopsis [Exact synthesis with majority gates.]
Author [Alan Mishchenko]
Affiliation [UC Berkeley]
Date [Ver. 1.0. Started - October 1, 2017.]
Revision [$Id: bmcMaj.c,v 1.00 2017/10/01 00:00:00 alanmi Exp $]
***********************************************************************/
#include "bmc.h"
#include "misc/extra/extra.h"
#include "misc/util/utilTruth.h"
#include "sat/glucose/AbcGlucose.h"
ABC_NAMESPACE_IMPL_START
////////////////////////////////////////////////////////////////////////
/// DECLARATIONS ///
////////////////////////////////////////////////////////////////////////
#define MAJ_NOBJS 32 // Const0 + Const1 + nVars + nNodes
typedef struct Maj_Man_t_ Maj_Man_t;
struct Maj_Man_t_
{
int nVars; // inputs
int nNodes; // internal nodes
int nObjs; // total objects (2 consts, nVars inputs, nNodes internal nodes)
int nWords; // the truth table size in 64-bit words
int iVar; // the next available SAT variable
int fUseConst; // use constant fanins
int fUseLine; // use cascade topology
Vec_Wrd_t * vInfo; // Const0 + Const1 + nVars + nNodes + Maj(nVars)
int VarMarks[MAJ_NOBJS][3][MAJ_NOBJS]; // variable marks
int VarVals[MAJ_NOBJS+2]; // values of the first 2 + nVars variables
Vec_Wec_t * vOutLits; // output vars
bmcg_sat_solver * pSat; // SAT solver
};
static inline word * Maj_ManTruth( Maj_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
////////////////////////////////////////////////////////////////////////
/// FUNCTION DEFINITIONS ///
////////////////////////////////////////////////////////////////////////
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Maj_ManValue( int iMint, int nVars )
{
int k, Count = 0;
for ( k = 0; k < nVars; k++ )
Count += (iMint >> k) & 1;
return (int)(Count > nVars/2);
}
Vec_Wrd_t * Maj_ManTruthTables( Maj_Man_t * p )
{
Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs + 1) );
int i, nMints = Abc_MaxInt( 64, 1 << p->nVars );
Abc_TtFill( Maj_ManTruth(p, 1), p->nWords );
for ( i = 0; i < p->nVars; i++ )
Abc_TtIthVar( Maj_ManTruth(p, i+2), i, p->nVars );
for ( i = 0; i < nMints; i++ )
if ( Maj_ManValue(i, p->nVars) )
Abc_TtSetBit( Maj_ManTruth(p, p->nObjs), i );
//Dau_DsdPrintFromTruth( Maj_ManTruth(p, p->nObjs), p->nVars );
return vInfo;
}
int Maj_ManMarkup( Maj_Man_t * p )
{
int i, k, j;
p->iVar = 1;
assert( p->nObjs <= MAJ_NOBJS );
// make exception for the first node
i = p->nVars + 2;
for ( k = 0; k < 3; k++ )
{
j = 4-k;
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
}
// assign variables for other nodes
for ( i = p->nVars + 3; i < p->nObjs; i++ )
{
for ( k = 0; k < 3; k++ )
{
if ( p->fUseLine && k == 0 )
{
j = i-1;
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
continue;
}
for ( j = (p->fUseConst && k == 2) ? 0 : 2; j < i - k; j++ )
{
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
}
}
}
printf( "The number of parameter variables = %d.\n", p->iVar );
return p->iVar;
// printout
for ( i = p->nVars + 2; i < p->nObjs; i++ )
{
printf( "Node %d\n", i );
for ( j = 0; j < p->nObjs; j++ )
{
for ( k = 0; k < 3; k++ )
printf( "%3d ", p->VarMarks[i][k][j] );
printf( "\n" );
}
}
return p->iVar;
}
Maj_Man_t * Maj_ManAlloc( int nVars, int nNodes, int fUseConst, int fUseLine )
{
Maj_Man_t * p = ABC_CALLOC( Maj_Man_t, 1 );
p->nVars = nVars;
p->nNodes = nNodes;
p->nObjs = 2 + nVars + nNodes;
p->fUseConst = fUseConst;
p->fUseLine = fUseLine;
p->nWords = Abc_TtWordNum(nVars);
p->vOutLits = Vec_WecStart( p->nObjs );
p->iVar = Maj_ManMarkup( p );
p->VarVals[1] = 1;
p->vInfo = Maj_ManTruthTables( p );
p->pSat = bmcg_sat_solver_start();
bmcg_sat_solver_set_nvars( p->pSat, p->iVar );
return p;
}
void Maj_ManFree( Maj_Man_t * p )
{
bmcg_sat_solver_stop( p->pSat );
Vec_WrdFree( p->vInfo );
Vec_WecFree( p->vOutLits );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int Maj_ManFindFanin( Maj_Man_t * p, int i, int k )
{
int j, Count = 0, iVar = -1;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] && bmcg_sat_solver_read_cex_varvalue(p->pSat, p->VarMarks[i][k][j]) )
{
iVar = j;
Count++;
}
assert( Count == 1 );
return iVar;
}
static inline int Maj_ManEval( Maj_Man_t * p )
{
static int Flag = 0;
int i, k, iMint; word * pFanins[3];
for ( i = p->nVars + 2; i < p->nObjs; i++ )
{
for ( k = 0; k < 3; k++ )
pFanins[k] = Maj_ManTruth( p, Maj_ManFindFanin(p, i, k) );
Abc_TtMaj( Maj_ManTruth(p, i), pFanins[0], pFanins[1], pFanins[2], p->nWords );
}
if ( Flag && p->nVars >= 6 )
iMint = Abc_TtFindLastDiffBit( Maj_ManTruth(p, p->nObjs-1), Maj_ManTruth(p, p->nObjs), p->nVars );
else
iMint = Abc_TtFindFirstDiffBit( Maj_ManTruth(p, p->nObjs-1), Maj_ManTruth(p, p->nObjs), p->nVars );
//Flag ^= 1;
assert( iMint < (1 << p->nVars) );
return iMint;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Maj_ManPrintSolution( Maj_Man_t * p )
{
int i, k, iVar;
printf( "Realization of %d-input majority using %d MAJ3 gates:\n", p->nVars, p->nNodes );
// for ( i = p->nVars + 2; i < p->nObjs; i++ )
for ( i = p->nObjs - 1; i >= p->nVars + 2; i-- )
{
printf( "%02d = MAJ(", i-2 );
for ( k = 2; k >= 0; k-- )
{
iVar = Maj_ManFindFanin( p, i, k );
if ( iVar >= 2 && iVar < p->nVars + 2 )
printf( " %c", 'a'+iVar-2 );
else if ( iVar < 2 )
printf( " %d", iVar );
else
printf( " %02d", iVar-2 );
}
printf( " )\n" );
}
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Maj_ManAddCnfStart( Maj_Man_t * p )
{
int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
// input constraints
for ( i = p->nVars + 2; i < p->nObjs; i++ )
{
for ( k = 0; k < 3; k++ )
{
int nLits = 0;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] )
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
assert( nLits > 0 );
// input uniqueness
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
for ( n = 0; n < nLits; n++ )
for ( m = n+1; m < nLits; m++ )
{
pLits2[0] = Abc_LitNot(pLits[n]);
pLits2[1] = Abc_LitNot(pLits[m]);
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
if ( k == 2 )
break;
// symmetry breaking
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
{
pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
}
}
// outputs should be used
for ( i = 2; i < p->nObjs - 1; i++ )
{
Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
assert( Vec_IntSize(vArray) > 0 );
if ( !bmcg_sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntSize(vArray) ) )
return 0;
}
return 1;
}
int Maj_ManAddCnf( Maj_Man_t * p, int iMint )
{
// save minterm values
int i, k, n, j, Value = Maj_ManValue(iMint, p->nVars);
for ( i = 0; i < p->nVars; i++ )
p->VarVals[i+2] = (iMint >> i) & 1;
bmcg_sat_solver_set_nvars( p->pSat, p->iVar + 4*p->nNodes );
//printf( "Adding clauses for minterm %d.\n", iMint );
for ( i = p->nVars + 2; i < p->nObjs; i++ )
{
// fanin connectivity
int iBaseSatVarI = p->iVar + 4*(i - p->nVars - 2);
for ( k = 0; k < 3; k++ )
{
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
{
int iBaseSatVarJ = p->iVar + 4*(j - p->nVars - 2);
for ( n = 0; n < 2; n++ )
{
int pLits[3], nLits = 0;
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
if ( j >= p->nVars + 2 )
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + 3, !n );
else if ( p->VarVals[j] == n )
continue;
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
// node functionality
for ( n = 0; n < 2; n++ )
{
if ( i == p->nObjs - 1 && n == Value )
continue;
for ( k = 0; k < 3; k++ )
{
int pLits[3], nLits = 0;
if ( k != 0 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, n );
if ( k != 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, n );
if ( k != 2 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, n );
if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 3, !n );
assert( nLits <= 3 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
p->iVar += 4*p->nNodes;
return 1;
}
int Maj_ManExactSynthesis( int nVars, int nNodes, int fUseConst, int fUseLine, int fVerbose )
{
int i, iMint = 0;
abctime clkTotal = Abc_Clock();
Maj_Man_t * p = Maj_ManAlloc( nVars, nNodes, fUseConst, fUseLine );
int status = Maj_ManAddCnfStart( p );
assert( status );
printf( "Running exact synthesis for %d-input majority with %d MAJ3 gates...\n", p->nVars, p->nNodes );
for ( i = 0; iMint != -1; i++ )
{
abctime clk = Abc_Clock();
if ( !Maj_ManAddCnf( p, iMint ) )
break;
status = bmcg_sat_solver_solve( p->pSat, NULL, 0 );
if ( fVerbose )
{
printf( "Iter %3d : ", i );
Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
printf( " Var =%5d ", p->iVar );
printf( "Cla =%6d ", bmcg_sat_solver_clausenum(p->pSat) );
printf( "Conf =%9d ", bmcg_sat_solver_conflictnum(p->pSat) );
Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
}
if ( status == GLUCOSE_UNSAT )
{
printf( "The problem has no solution.\n" );
break;
}
iMint = Maj_ManEval( p );
}
if ( iMint == -1 )
Maj_ManPrintSolution( p );
Maj_ManFree( p );
Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
return iMint == -1;
}
typedef struct Exa_Man_t_ Exa_Man_t;
struct Exa_Man_t_
{
int nVars; // inputs
int nNodes; // internal nodes
int nObjs; // total objects (nVars inputs + nNodes internal nodes)
int nWords; // the truth table size in 64-bit words
int iVar; // the next available SAT variable
word * pTruth; // truth table
Vec_Wrd_t * vInfo; // nVars + nNodes + 1
int VarMarks[MAJ_NOBJS][2][MAJ_NOBJS]; // variable marks
int VarVals[MAJ_NOBJS]; // values of the first nVars variables
Vec_Wec_t * vOutLits; // output vars
bmcg_sat_solver * pSat; // SAT solver
};
static inline word * Exa_ManTruth( Exa_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
Vec_Wrd_t * Exa_ManTruthTables( Exa_Man_t * p )
{
Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs+1) ); int i;
for ( i = 0; i < p->nVars; i++ )
Abc_TtIthVar( Exa_ManTruth(p, i), i, p->nVars );
//Dau_DsdPrintFromTruth( Exa_ManTruth(p, p->nObjs), p->nVars );
return vInfo;
}
int Exa_ManMarkup( Exa_Man_t * p )
{
int i, k, j;
assert( p->nObjs <= MAJ_NOBJS );
// assign functionality
p->iVar = 1 + p->nNodes * 3;
// assign connectivity variables
for ( i = p->nVars; i < p->nObjs; i++ )
{
for ( k = 0; k < 2; k++ )
{
if ( i == p->nObjs - 1 && k == 0 )
{
j = p->nObjs - 2;
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
continue;
}
for ( j = 1 - k; j < i - k; j++ )
{
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
}
}
}
printf( "The number of parameter variables = %d.\n", p->iVar );
return p->iVar;
// printout
for ( i = p->nVars; i < p->nObjs; i++ )
{
printf( "Node %d\n", i );
for ( j = 0; j < p->nObjs; j++ )
{
for ( k = 0; k < 2; k++ )
printf( "%3d ", p->VarMarks[i][k][j] );
printf( "\n" );
}
}
return p->iVar;
}
Exa_Man_t * Exa_ManAlloc( int nVars, int nNodes, word * pTruth )
{
Exa_Man_t * p = ABC_CALLOC( Exa_Man_t, 1 );
p->nVars = nVars;
p->nNodes = nNodes;
p->nObjs = nVars + nNodes;
p->nWords = Abc_TtWordNum(nVars);
p->pTruth = pTruth;
p->vOutLits = Vec_WecStart( p->nObjs );
p->iVar = Exa_ManMarkup( p );
p->vInfo = Exa_ManTruthTables( p );
p->pSat = bmcg_sat_solver_start();
bmcg_sat_solver_set_nvars( p->pSat, p->iVar );
return p;
}
void Exa_ManFree( Exa_Man_t * p )
{
bmcg_sat_solver_stop( p->pSat );
Vec_WrdFree( p->vInfo );
Vec_WecFree( p->vOutLits );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int Exa_ManFindFanin( Exa_Man_t * p, int i, int k )
{
int j, Count = 0, iVar = -1;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] && bmcg_sat_solver_read_cex_varvalue(p->pSat, p->VarMarks[i][k][j]) )
{
iVar = j;
Count++;
}
assert( Count == 1 );
return iVar;
}
static inline int Exa_ManEval( Exa_Man_t * p )
{
static int Flag = 0;
int i, k, iMint; word * pFanins[2];
for ( i = p->nVars; i < p->nObjs; i++ )
{
int iVarStart = 1 + 3*(i - p->nVars);
for ( k = 0; k < 2; k++ )
pFanins[k] = Exa_ManTruth( p, Exa_ManFindFanin(p, i, k) );
Abc_TtConst0( Exa_ManTruth(p, i), p->nWords );
for ( k = 1; k < 4; k++ )
{
if ( !bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart+k-1) )
continue;
Abc_TtAndCompl( Exa_ManTruth(p, p->nObjs), pFanins[0], !(k&1), pFanins[1], !(k>>1), p->nWords );
Abc_TtOr( Exa_ManTruth(p, i), Exa_ManTruth(p, i), Exa_ManTruth(p, p->nObjs), p->nWords );
}
}
if ( Flag && p->nVars >= 6 )
iMint = Abc_TtFindLastDiffBit( Exa_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
else
iMint = Abc_TtFindFirstDiffBit( Exa_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
//Flag ^= 1;
assert( iMint < (1 << p->nVars) );
return iMint;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
void Exa_ManPrintSolution( Exa_Man_t * p, int fCompl )
{
int i, k, iVar;
printf( "Realization of given %d-input function using %d two-input gates:\n", p->nVars, p->nNodes );
// for ( i = p->nVars + 2; i < p->nObjs; i++ )
for ( i = p->nObjs - 1; i >= p->nVars; i-- )
{
int iVarStart = 1 + 3*(i - p->nVars);
int Val1 = bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart);
int Val2 = bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart+1);
int Val3 = bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart+2);
if ( i == p->nObjs - 1 && fCompl )
printf( "%02d = 4\'b%d%d%d1(", i, !Val3, !Val2, !Val1 );
else
printf( "%02d = 4\'b%d%d%d0(", i, Val3, Val2, Val1 );
for ( k = 1; k >= 0; k-- )
{
iVar = Exa_ManFindFanin( p, i, k );
if ( iVar >= 0 && iVar < p->nVars )
printf( " %c", 'a'+iVar );
else
printf( " %02d", iVar );
}
printf( " )\n" );
}
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
int Exa_ManAddCnfStart( Exa_Man_t * p, int fOnlyAnd )
{
int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
// input constraints
for ( i = p->nVars; i < p->nObjs; i++ )
{
int iVarStart = 1 + 3*(i - p->nVars);
for ( k = 0; k < 2; k++ )
{
int nLits = 0;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] )
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
assert( nLits > 0 );
// input uniqueness
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
for ( n = 0; n < nLits; n++ )
for ( m = n+1; m < nLits; m++ )
{
pLits2[0] = Abc_LitNot(pLits[n]);
pLits2[1] = Abc_LitNot(pLits[m]);
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
if ( k == 1 )
break;
// symmetry breaking
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
{
pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
}
// node ordering
for ( j = p->nVars; j < i; j++ )
for ( n = 0; n < p->nObjs; n++ ) if ( p->VarMarks[i][0][n] )
for ( m = n+1; m < p->nObjs; m++ ) if ( p->VarMarks[j][0][m] )
{
pLits2[0] = Abc_Var2Lit( p->VarMarks[i][0][n], 1 );
pLits2[1] = Abc_Var2Lit( p->VarMarks[j][0][m], 1 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
// two input functions
for ( k = 0; k < 3; k++ )
{
pLits[0] = Abc_Var2Lit( iVarStart, k==1 );
pLits[1] = Abc_Var2Lit( iVarStart+1, k==2 );
pLits[2] = Abc_Var2Lit( iVarStart+2, k!=0 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, 3 ) )
return 0;
}
if ( fOnlyAnd )
{
pLits[0] = Abc_Var2Lit( iVarStart, 1 );
pLits[1] = Abc_Var2Lit( iVarStart+1, 1 );
pLits[2] = Abc_Var2Lit( iVarStart+2, 0 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, 3 ) )
return 0;
}
}
// outputs should be used
for ( i = 0; i < p->nObjs - 1; i++ )
{
Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
assert( Vec_IntSize(vArray) > 0 );
if ( !bmcg_sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntSize(vArray) ) )
return 0;
}
return 1;
}
int Exa_ManAddCnf( Exa_Man_t * p, int iMint )
{
// save minterm values
int i, k, n, j, Value = Abc_TtGetBit(p->pTruth, iMint);
for ( i = 0; i < p->nVars; i++ )
p->VarVals[i] = (iMint >> i) & 1;
bmcg_sat_solver_set_nvars( p->pSat, p->iVar + 3*p->nNodes );
//printf( "Adding clauses for minterm %d with value %d.\n", iMint, Value );
for ( i = p->nVars; i < p->nObjs; i++ )
{
// fanin connectivity
int iVarStart = 1 + 3*(i - p->nVars);
int iBaseSatVarI = p->iVar + 3*(i - p->nVars);
for ( k = 0; k < 2; k++ )
{
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
{
int iBaseSatVarJ = p->iVar + 3*(j - p->nVars);
for ( n = 0; n < 2; n++ )
{
int pLits[3], nLits = 0;
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
if ( j >= p->nVars )
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + 2, !n );
else if ( p->VarVals[j] == n )
continue;
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
// node functionality
for ( n = 0; n < 2; n++ )
{
if ( i == p->nObjs - 1 && n == Value )
continue;
for ( k = 0; k < 4; k++ )
{
int pLits[4], nLits = 0;
if ( k == 0 && n == 1 )
continue;
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, (k&1) );
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, (k>>1) );
if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, !n );
if ( k > 0 ) pLits[nLits++] = Abc_Var2Lit( iVarStart + k-1, n );
assert( nLits <= 4 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
p->iVar += 3*p->nNodes;
return 1;
}
void Exa_ManExactSynthesis( char * pTtStr, int nVars, int nNodes, int fOnlyAnd, int fVerbose )
{
int i, status, iMint = 1;
abctime clkTotal = Abc_Clock();
Exa_Man_t * p; int fCompl = 0;
word pTruth[16]; Abc_TtReadHex( pTruth, pTtStr );
assert( nVars <= 10 );
p = Exa_ManAlloc( nVars, nNodes, pTruth );
if ( pTruth[0] & 1 ) { fCompl = 1; Abc_TtNot( pTruth, p->nWords ); }
status = Exa_ManAddCnfStart( p, fOnlyAnd );
assert( status );
printf( "Running exact synthesis for %d-input function with %d two-input gates...\n", p->nVars, p->nNodes );
for ( i = 0; iMint != -1; i++ )
{
abctime clk = Abc_Clock();
if ( !Exa_ManAddCnf( p, iMint ) )
break;
status = bmcg_sat_solver_solve( p->pSat, NULL, 0 );
if ( fVerbose )
{
printf( "Iter %3d : ", i );
Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
printf( " Var =%5d ", p->iVar );
printf( "Cla =%6d ", bmcg_sat_solver_clausenum(p->pSat) );
printf( "Conf =%9d ", bmcg_sat_solver_conflictnum(p->pSat) );
Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
}
if ( status == GLUCOSE_UNSAT )
{
printf( "The problem has no solution.\n" );
break;
}
iMint = Exa_ManEval( p );
}
if ( iMint == -1 )
Exa_ManPrintSolution( p, fCompl );
Exa_ManFree( p );
Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
}
typedef struct Exa3_Man_t_ Exa3_Man_t;
struct Exa3_Man_t_
{
int nVars; // inputs
int nNodes; // internal nodes
int nLutSize; // lut size
int LutMask; // lut mask
int nObjs; // total objects (nVars inputs + nNodes internal nodes)
int nWords; // the truth table size in 64-bit words
int iVar; // the next available SAT variable
word * pTruth; // truth table
Vec_Wrd_t * vInfo; // nVars + nNodes + 1
int VarMarks[MAJ_NOBJS][6][MAJ_NOBJS]; // variable marks
int VarVals[MAJ_NOBJS]; // values of the first nVars variables
Vec_Wec_t * vOutLits; // output vars
bmcg_sat_solver * pSat; // SAT solver
};
static inline word * Exa3_ManTruth( Exa3_Man_t * p, int v ) { return Vec_WrdEntryP( p->vInfo, p->nWords * v ); }
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static Vec_Wrd_t * Exa3_ManTruthTables( Exa3_Man_t * p )
{
Vec_Wrd_t * vInfo = p->vInfo = Vec_WrdStart( p->nWords * (p->nObjs+1) ); int i;
for ( i = 0; i < p->nVars; i++ )
Abc_TtIthVar( Exa3_ManTruth(p, i), i, p->nVars );
//Dau_DsdPrintFromTruth( Exa3_ManTruth(p, p->nObjs), p->nVars );
return vInfo;
}
static int Exa3_ManMarkup( Exa3_Man_t * p )
{
int i, k, j;
assert( p->nObjs <= MAJ_NOBJS );
// assign functionality variables
p->iVar = 1 + p->LutMask * p->nNodes;
// assign connectivity variables
for ( i = p->nVars; i < p->nObjs; i++ )
{
for ( k = 0; k < p->nLutSize; k++ )
{
if ( i == p->nObjs - 1 && k == 0 )
{
j = p->nObjs - 2;
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
continue;
}
for ( j = p->nLutSize - 1 - k; j < i - k; j++ )
{
Vec_WecPush( p->vOutLits, j, Abc_Var2Lit(p->iVar, 0) );
p->VarMarks[i][k][j] = p->iVar++;
}
}
}
printf( "The number of parameter variables = %d.\n", p->iVar );
return p->iVar;
// printout
for ( i = p->nObjs - 1; i >= p->nVars; i-- )
{
printf( " Node %2d\n", i );
for ( j = 0; j < p->nObjs; j++ )
{
printf( "Fanin %2d : ", j );
for ( k = 0; k < p->nLutSize; k++ )
printf( "%3d ", p->VarMarks[i][k][j] );
printf( "\n" );
}
}
return p->iVar;
}
static Exa3_Man_t * Exa3_ManAlloc( int nVars, int nNodes, int nLutSize, word * pTruth )
{
Exa3_Man_t * p = ABC_CALLOC( Exa3_Man_t, 1 );
p->nVars = nVars;
p->nNodes = nNodes;
p->nLutSize = nLutSize;
p->LutMask = (1 << nLutSize) - 1;
p->nObjs = nVars + nNodes;
p->nWords = Abc_TtWordNum(nVars);
p->pTruth = pTruth;
p->vOutLits = Vec_WecStart( p->nObjs );
p->iVar = Exa3_ManMarkup( p );
p->vInfo = Exa3_ManTruthTables( p );
p->pSat = bmcg_sat_solver_start();
bmcg_sat_solver_set_nvars( p->pSat, p->iVar );
return p;
}
static void Exa3_ManFree( Exa3_Man_t * p )
{
bmcg_sat_solver_stop( p->pSat );
Vec_WrdFree( p->vInfo );
Vec_WecFree( p->vOutLits );
ABC_FREE( p );
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static inline int Exa3_ManFindFanin( Exa3_Man_t * p, int i, int k )
{
int j, Count = 0, iVar = -1;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] && bmcg_sat_solver_read_cex_varvalue(p->pSat, p->VarMarks[i][k][j]) )
{
iVar = j;
Count++;
}
assert( Count == 1 );
return iVar;
}
static inline int Exa3_ManEval( Exa3_Man_t * p )
{
static int Flag = 0;
int i, k, j, iMint; word * pFanins[6];
for ( i = p->nVars; i < p->nObjs; i++ )
{
int iVarStart = 1 + p->LutMask*(i - p->nVars);
for ( k = 0; k < p->nLutSize; k++ )
pFanins[k] = Exa3_ManTruth( p, Exa3_ManFindFanin(p, i, k) );
Abc_TtConst0( Exa3_ManTruth(p, i), p->nWords );
for ( k = 1; k <= p->LutMask; k++ )
{
if ( !bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart+k-1) )
continue;
// Abc_TtAndCompl( Exa3_ManTruth(p, p->nObjs), pFanins[0], !(k&1), pFanins[1], !(k>>1), p->nWords );
Abc_TtConst1( Exa3_ManTruth(p, p->nObjs), p->nWords );
for ( j = 0; j < p->nLutSize; j++ )
Abc_TtAndCompl( Exa3_ManTruth(p, p->nObjs), Exa3_ManTruth(p, p->nObjs), 0, pFanins[j], !((k >> j) & 1), p->nWords );
Abc_TtOr( Exa3_ManTruth(p, i), Exa3_ManTruth(p, i), Exa3_ManTruth(p, p->nObjs), p->nWords );
}
}
if ( Flag && p->nVars >= 6 )
iMint = Abc_TtFindLastDiffBit( Exa3_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
else
iMint = Abc_TtFindFirstDiffBit( Exa3_ManTruth(p, p->nObjs-1), p->pTruth, p->nVars );
//Flag ^= 1;
assert( iMint < (1 << p->nVars) );
return iMint;
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static void Exa3_ManPrintSolution( Exa3_Man_t * p, int fCompl )
{
int i, k, iVar;
printf( "Realization of given %d-input function using %d %d-input LUTs:\n", p->nVars, p->nNodes, p->nLutSize );
for ( i = p->nObjs - 1; i >= p->nVars; i-- )
{
int Val, iVarStart = 1 + p->LutMask*(i - p->nVars);
printf( "%02d = %d\'b", i, 1 << p->nLutSize );
for ( k = p->LutMask - 1; k >= 0; k-- )
{
Val = bmcg_sat_solver_read_cex_varvalue(p->pSat, iVarStart+k);
if ( i == p->nObjs - 1 && fCompl )
printf( "%d", !Val );
else
printf( "%d", Val );
}
if ( i == p->nObjs - 1 && fCompl )
printf( "1(" );
else
printf( "0(" );
for ( k = p->nLutSize - 1; k >= 0; k-- )
{
iVar = Exa3_ManFindFanin( p, i, k );
if ( iVar >= 0 && iVar < p->nVars )
printf( " %c", 'a'+iVar );
else
printf( " %02d", iVar );
}
printf( " )\n" );
}
}
/**Function*************************************************************
Synopsis []
Description []
SideEffects []
SeeAlso []
***********************************************************************/
static int Exa3_ManAddCnfStart( Exa3_Man_t * p, int fOnlyAnd )
{
int pLits[MAJ_NOBJS], pLits2[2], i, j, k, n, m;
// input constraints
for ( i = p->nVars; i < p->nObjs; i++ )
{
int iVarStart = 1 + p->LutMask*(i - p->nVars);
for ( k = 0; k < p->nLutSize; k++ )
{
int nLits = 0;
for ( j = 0; j < p->nObjs; j++ )
if ( p->VarMarks[i][k][j] )
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 0 );
assert( nLits > 0 );
// input uniqueness
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
for ( n = 0; n < nLits; n++ )
for ( m = n+1; m < nLits; m++ )
{
pLits2[0] = Abc_LitNot(pLits[n]);
pLits2[1] = Abc_LitNot(pLits[m]);
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
if ( k == p->nLutSize - 1 )
break;
// symmetry breaking
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
for ( n = j; n < p->nObjs; n++ ) if ( p->VarMarks[i][k+1][n] )
{
pLits2[0] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits2[1] = Abc_Var2Lit( p->VarMarks[i][k+1][n], 1 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
}
// node ordering
for ( j = p->nVars; j < i; j++ )
for ( n = 0; n < p->nObjs; n++ ) if ( p->VarMarks[i][0][n] )
for ( m = n+1; m < p->nObjs; m++ ) if ( p->VarMarks[j][0][m] )
{
pLits2[0] = Abc_Var2Lit( p->VarMarks[i][0][n], 1 );
pLits2[1] = Abc_Var2Lit( p->VarMarks[j][0][m], 1 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits2, 2 ) )
return 0;
}
if ( p->nLutSize != 2 )
continue;
// two-input functions
for ( k = 0; k < 3; k++ )
{
pLits[0] = Abc_Var2Lit( iVarStart, k==1 );
pLits[1] = Abc_Var2Lit( iVarStart+1, k==2 );
pLits[2] = Abc_Var2Lit( iVarStart+2, k!=0 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, 3 ) )
return 0;
}
if ( fOnlyAnd )
{
pLits[0] = Abc_Var2Lit( iVarStart, 1 );
pLits[1] = Abc_Var2Lit( iVarStart+1, 1 );
pLits[2] = Abc_Var2Lit( iVarStart+2, 0 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, 3 ) )
return 0;
}
}
// outputs should be used
for ( i = 0; i < p->nObjs - 1; i++ )
{
Vec_Int_t * vArray = Vec_WecEntry(p->vOutLits, i);
assert( Vec_IntSize(vArray) > 0 );
if ( !bmcg_sat_solver_addclause( p->pSat, Vec_IntArray(vArray), Vec_IntSize(vArray) ) )
return 0;
}
return 1;
}
static int Exa3_ManAddCnf( Exa3_Man_t * p, int iMint )
{
// save minterm values
int i, k, n, j, Value = Abc_TtGetBit(p->pTruth, iMint);
for ( i = 0; i < p->nVars; i++ )
p->VarVals[i] = (iMint >> i) & 1;
// sat_solver_setnvars( p->pSat, p->iVar + (p->nLutSize+1)*p->nNodes );
bmcg_sat_solver_set_nvars( p->pSat, p->iVar + (p->nLutSize+1)*p->nNodes );
//printf( "Adding clauses for minterm %d with value %d.\n", iMint, Value );
for ( i = p->nVars; i < p->nObjs; i++ )
{
// fanin connectivity
int iVarStart = 1 + p->LutMask*(i - p->nVars);
int iBaseSatVarI = p->iVar + (p->nLutSize+1)*(i - p->nVars);
for ( k = 0; k < p->nLutSize; k++ )
{
for ( j = 0; j < p->nObjs; j++ ) if ( p->VarMarks[i][k][j] )
{
int iBaseSatVarJ = p->iVar + (p->nLutSize+1)*(j - p->nVars);
for ( n = 0; n < 2; n++ )
{
int pLits[3], nLits = 0;
pLits[nLits++] = Abc_Var2Lit( p->VarMarks[i][k][j], 1 );
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + k, n );
if ( j >= p->nVars )
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarJ + p->nLutSize, !n );
else if ( p->VarVals[j] == n )
continue;
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
// node functionality
for ( n = 0; n < 2; n++ )
{
if ( i == p->nObjs - 1 && n == Value )
continue;
for ( k = 0; k <= p->LutMask; k++ )
{
int pLits[8], nLits = 0;
if ( k == 0 && n == 1 )
continue;
//pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 0, (k&1) );
//pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 1, (k>>1) );
//if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + 2, !n );
for ( j = 0; j < p->nLutSize; j++ )
pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + j, (k >> j) & 1 );
if ( i != p->nObjs - 1 ) pLits[nLits++] = Abc_Var2Lit( iBaseSatVarI + j, !n );
if ( k > 0 ) pLits[nLits++] = Abc_Var2Lit( iVarStart + k-1, n );
assert( nLits <= p->nLutSize+2 );
if ( !bmcg_sat_solver_addclause( p->pSat, pLits, nLits ) )
return 0;
}
}
}
p->iVar += (p->nLutSize+1)*p->nNodes;
return 1;
}
void Exa3_ManExactSynthesis( char * pTtStr, int nVars, int nNodes, int nLutSize, int fOnlyAnd, int fVerbose )
{
int i, status, iMint = 1;
abctime clkTotal = Abc_Clock();
Exa3_Man_t * p; int fCompl = 0;
word pTruth[16]; Abc_TtReadHex( pTruth, pTtStr );
assert( nVars <= 10 );
assert( nLutSize <= 6 );
p = Exa3_ManAlloc( nVars, nNodes, nLutSize, pTruth );
if ( pTruth[0] & 1 ) { fCompl = 1; Abc_TtNot( pTruth, p->nWords ); }
status = Exa3_ManAddCnfStart( p, fOnlyAnd );
assert( status );
printf( "Running exact synthesis for %d-input function with %d %d-input LUTs...\n", p->nVars, p->nNodes, p->nLutSize );
for ( i = 0; iMint != -1; i++ )
{
abctime clk = Abc_Clock();
if ( !Exa3_ManAddCnf( p, iMint ) )
break;
status = bmcg_sat_solver_solve( p->pSat, NULL, 0 );
if ( fVerbose )
{
printf( "Iter %3d : ", i );
Extra_PrintBinary( stdout, (unsigned *)&iMint, p->nVars );
printf( " Var =%5d ", p->iVar );
printf( "Cla =%6d ", bmcg_sat_solver_clausenum(p->pSat) );
printf( "Conf =%9d ", bmcg_sat_solver_conflictnum(p->pSat) );
Abc_PrintTime( 1, "Time", Abc_Clock() - clk );
}
if ( status == GLUCOSE_UNSAT )
{
printf( "The problem has no solution.\n" );
break;
}
iMint = Exa3_ManEval( p );
}
if ( iMint == -1 )
Exa3_ManPrintSolution( p, fCompl );
Exa3_ManFree( p );
Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
}
////////////////////////////////////////////////////////////////////////
/// END OF FILE ///
////////////////////////////////////////////////////////////////////////
ABC_NAMESPACE_IMPL_END