Another variation on exact synthesis.

1 files changed, 354 insertions, 0 deletions

diff --git a/src/sat/bmc/bmcMaj.c b/src/sat/bmc/bmcMaj.c
index 31460b0e..59ebbae5 100644
--- a/src/sat/bmc/bmcMaj.c
+++ b/src/sat/bmc/bmcMaj.c
@@ -381,6 +381,360 @@ void Maj_ManExactSynthesis( int nVars, int nNodes, int fUseConst, int fUseLine,
     Abc_PrintTime( 1, "Total runtime", Abc_Clock() - clkTotal );
 }
 
+
+
+
+
+
+
+
+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 variables for truth tables
+    p->iVar = 1 + p->nNodes * 3;
+    // assign variables for     other nodes
+    for ( i = p->nVars; i < p->nObjs; i++ )
+    {
+        for ( k = 0; k < 2; k++ )
+        {
+            for ( j = 0; 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 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;
+            }
+        }
+        // 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;
+        }
+    }
+    // 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 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 );
+    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 );
+}
+
 ////////////////////////////////////////////////////////////////////////
 ///                       END OF FILE                                ///
 ////////////////////////////////////////////////////////////////////////