src/Backend/satencoder.cc

   1 #include "satencoder.h"
   2 #include "structs.h"
   3 #include "csolver.h"
   4 #include "boolean.h"
   5 #include "constraint.h"
   6 #include "common.h"
   7 #include "element.h"
   8 #include "function.h"
   9 #include "tableentry.h"
  10 #include "table.h"
  11 #include "order.h"
  12 #include "predicate.h"
  13 #include "set.h"
  14 #include "tunable.h"
  15
  16 SATEncoder::SATEncoder(CSolver *_solver) :
  17         cnf(createCNF()),
  18         solver(_solver),
  19         vector(allocDefVectorEdge()) {
  20 }
  21
  22 SATEncoder::~SATEncoder() {
  23         deleteCNF(cnf);
  24         deleteVectorEdge(vector);
  25 }
  26
  27 void SATEncoder::resetSATEncoder() {
  28         resetCNF(cnf);
  29         booledgeMap.reset();
  30 }
  31
  32 int SATEncoder::solve(long timeout) {
  33         cnf->solver->timeout = timeout;
  34         return solveCNF(cnf);
  35 }
  36
  37 void SATEncoder::encodeAllSATEncoder(CSolver *csolver) {
  38         SetIteratorBooleanEdge *iterator = csolver->getConstraints();
  39         while (iterator->hasNext()) {
  40                 BooleanEdge constraint = iterator->next();
  41                 Edge c = encodeConstraintSATEncoder(constraint);
  42                 addConstraintCNF(cnf, c);
  43         }
  44         delete iterator;
  45 }
  46
  47 Edge SATEncoder::encodeConstraintSATEncoder(BooleanEdge c) {
  48         Edge result;
  49         Boolean *constraint = c.getBoolean();
  50
  51         if (booledgeMap.contains(constraint)) {
  52                 Edge e = {(Node *) booledgeMap.get(constraint)};
  53                 return c.isNegated() ? constraintNegate(e) : e;
  54         }
  55
  56         switch (constraint->type) {
  57         case ORDERCONST:
  58                 result = encodeOrderSATEncoder((BooleanOrder *) constraint);
  59                 break;
  60         case BOOLEANVAR:
  61                 result = encodeVarSATEncoder((BooleanVar *) constraint);
  62                 break;
  63         case LOGICOP:
  64                 result = encodeLogicSATEncoder((BooleanLogic *) constraint);
  65                 break;
  66         case PREDICATEOP:
  67                 result = encodePredicateSATEncoder((BooleanPredicate *) constraint);
  68                 break;
  69         case BOOLCONST:
  70                 result = ((BooleanConst *) constraint)->isTrue() ? E_True : E_False;
  71                 break;
  72         default:
  73                 model_print("Unhandled case in encodeConstraintSATEncoder %u", constraint->type);
  74                 exit(-1);
  75         }
  76         Polarity p = constraint->polarity;
  77         uint pSize = constraint->parents.getSize();
  78
  79         if ( !edgeIsVarConst(result) && pSize > (uint)solver->getTuner()->getTunable(PROXYVARIABLE, &proxyparameter) ) {
  80                 Edge e = getNewVarSATEncoder();
  81                 generateProxy(cnf, result, e, p);
  82                 booledgeMap.put(constraint, e.node_ptr);
  83                 result = e;
  84         }
  85
  86         return c.isNegated() ? constraintNegate(result) : result;
  87 }
  88
  89 void SATEncoder::getArrayNewVarsSATEncoder(uint num, Edge *carray) {
  90         for (uint i = 0; i < num; i++)
  91                 carray[i] = getNewVarSATEncoder();
  92 }
  93
  94 Edge SATEncoder::getNewVarSATEncoder() {
  95         return constraintNewVar(cnf);
  96 }
  97
  98 Edge SATEncoder::encodeVarSATEncoder(BooleanVar *constraint) {
  99         if (edgeIsNull(constraint->var)) {
 100                 constraint->var = getNewVarSATEncoder();
 101         }
 102         return constraint->var;
 103 }
 104
 105 Edge SATEncoder::encodeLogicSATEncoder(BooleanLogic *constraint) {
 106         Edge array[constraint->inputs.getSize()];
 107         for (uint i = 0; i < constraint->inputs.getSize(); i++)
 108                 array[i] = encodeConstraintSATEncoder(constraint->inputs.get(i));
 109
 110         switch (constraint->op) {
 111         case SATC_AND:
 112                 return constraintAND(cnf, constraint->inputs.getSize(), array);
 113         case SATC_NOT:
 114                 return constraintNegate(array[0]);
 115         case SATC_IFF:
 116                 ASSERT(constraint->inputs.getSize() == 2);
 117                 return constraintIFF(cnf, array[0], array[1]);
 118         case SATC_OR:
 119         case SATC_XOR:
 120         case SATC_IMPLIES:
 121         //Don't handle, translate these away...
 122         default:
 123                 model_print("Unhandled case in encodeLogicSATEncoder %u", constraint->op);
 124                 exit(-1);
 125         }
 126 }
 127
 128 Edge SATEncoder::encodePredicateSATEncoder(BooleanPredicate *constraint) {
 129         switch (constraint->predicate->type) {
 130         case TABLEPRED:
 131                 return encodeTablePredicateSATEncoder(constraint);
 132         case OPERATORPRED:
 133                 return encodeOperatorPredicateSATEncoder(constraint);
 134         default:
 135                 ASSERT(0);
 136         }
 137         return E_BOGUS;
 138 }
 139
 140 Edge SATEncoder::encodeTablePredicateSATEncoder(BooleanPredicate *constraint) {
 141         switch (constraint->encoding.type) {
 142         case ENUMERATEIMPLICATIONS:
 143         case ENUMERATEIMPLICATIONSNEGATE:
 144                 return encodeEnumTablePredicateSATEncoder(constraint);
 145         case CIRCUIT:
 146                 ASSERT(0);
 147                 break;
 148         default:
 149                 ASSERT(0);
 150         }
 151         return E_BOGUS;
 152 }
 153
 154 void SATEncoder::encodeElementSATEncoder(Element *element) {
 155         /* Check to see if we have already encoded this element. */
 156         if (element->getElementEncoding()->variables != NULL)
 157                 return;
 158
 159         /* Need to encode. */
 160         switch ( element->type) {
 161         case ELEMFUNCRETURN:
 162                 generateElementEncoding(element);
 163                 encodeElementFunctionSATEncoder((ElementFunction *) element);
 164                 break;
 165         case ELEMSET:
 166                 generateElementEncoding(element);
 167                 return;
 168         case ELEMCONST:
 169                 return;
 170         default:
 171                 ASSERT(0);
 172         }
 173 }
 174
 175 void SATEncoder::encodeElementFunctionSATEncoder(ElementFunction *function) {
 176         switch (function->getFunction()->type) {
 177         case TABLEFUNC:
 178                 encodeTableElementFunctionSATEncoder(function);
 179                 break;
 180         case OPERATORFUNC:
 181                 encodeOperatorElementFunctionSATEncoder(function);
 182                 break;
 183         default:
 184                 ASSERT(0);
 185         }
 186 }
 187
 188 void SATEncoder::encodeTableElementFunctionSATEncoder(ElementFunction *function) {
 189         switch (function->getElementFunctionEncoding()->type) {
 190         case ENUMERATEIMPLICATIONS:
 191                 encodeEnumTableElemFunctionSATEncoder(function);
 192                 break;
 193         case CIRCUIT:
 194                 ASSERT(0);
 195                 break;
 196         default:
 197                 ASSERT(0);
 198         }
 199 }