src/Backend/satencoder.c

   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 "orderpair.h"
  14 #include "set.h"
  15
  16 SATEncoder * allocSATEncoder() {
  17         SATEncoder *This=ourmalloc(sizeof (SATEncoder));
  18         This->varcount=1;
  19         This->cnf=createCNF();
  20         return This;
  21 }
  22
  23 void deleteSATEncoder(SATEncoder *This) {
  24         deleteCNF(This->cnf);
  25         ourfree(This);
  26 }
  27
  28 Edge getElementValueConstraint(SATEncoder* This, Element* elem, uint64_t value) {
  29         generateElementEncodingVariables(This, getElementEncoding(elem));
  30         switch(getElementEncoding(elem)->type){
  31                 case ONEHOT:
  32                         //FIXME
  33                         ASSERT(0);
  34                         break;
  35                 case UNARY:
  36                         ASSERT(0);
  37                         break;
  38                 case BINARYINDEX:
  39                         return getElementValueBinaryIndexConstraint(This, elem, value);
  40                         break;
  41                 case ONEHOTBINARY:
  42                         ASSERT(0);
  43                         break;
  44                 case BINARYVAL:
  45                         ASSERT(0);
  46                         break;
  47                 default:
  48                         ASSERT(0);
  49                         break;
  50         }
  51         return E_BOGUS;
  52 }
  53
  54 Edge getElementValueBinaryIndexConstraint(SATEncoder * This, Element* elem, uint64_t value) {
  55         ASTNodeType type = GETELEMENTTYPE(elem);
  56         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  57         ElementEncoding* elemEnc = getElementEncoding(elem);
  58         for(uint i=0; i<elemEnc->encArraySize; i++){
  59                 if( isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value){
  60                         return generateBinaryConstraint(This->cnf, elemEnc->numVars, elemEnc->variables, i);
  61                 }
  62         }
  63         return E_BOGUS;
  64 }
  65
  66 void encodeAllSATEncoder(CSolver *csolver, SATEncoder * This) {
  67         VectorBoolean *constraints=csolver->constraints;
  68         uint size=getSizeVectorBoolean(constraints);
  69         for(uint i=0;i<size;i++) {
  70                 Boolean *constraint=getVectorBoolean(constraints, i);
  71                 Edge c= encodeConstraintSATEncoder(This, constraint);
  72                 printCNF(c);
  73                 printf("\n\n");
  74                 addConstraintCNF(This->cnf, c);
  75         }
  76 }
  77
  78 Edge encodeConstraintSATEncoder(SATEncoder *This, Boolean *constraint) {
  79         switch(GETBOOLEANTYPE(constraint)) {
  80         case ORDERCONST:
  81                 return encodeOrderSATEncoder(This, (BooleanOrder *) constraint);
  82         case BOOLEANVAR:
  83                 return encodeVarSATEncoder(This, (BooleanVar *) constraint);
  84         case LOGICOP:
  85                 return encodeLogicSATEncoder(This, (BooleanLogic *) constraint);
  86         case PREDICATEOP:
  87                 return encodePredicateSATEncoder(This, (BooleanPredicate *) constraint);
  88         default:
  89                 model_print("Unhandled case in encodeConstraintSATEncoder %u", GETBOOLEANTYPE(constraint));
  90                 exit(-1);
  91         }
  92 }
  93
  94 void getArrayNewVarsSATEncoder(SATEncoder* encoder, uint num, Edge * carray) {
  95         for(uint i=0;i<num;i++)
  96                 carray[i]=getNewVarSATEncoder(encoder);
  97 }
  98
  99 Edge getNewVarSATEncoder(SATEncoder *This) {
 100         return constraintNewVar(This->cnf);
 101 }
 102
 103 Edge encodeVarSATEncoder(SATEncoder *This, BooleanVar * constraint) {
 104         if (edgeIsNull(constraint->var)) {
 105                 constraint->var=getNewVarSATEncoder(This);
 106         }
 107         return constraint->var;
 108 }
 109
 110 Edge encodeLogicSATEncoder(SATEncoder *This, BooleanLogic * constraint) {
 111         Edge array[getSizeArrayBoolean(&constraint->inputs)];
 112         for(uint i=0;i<getSizeArrayBoolean(&constraint->inputs);i++)
 113                 array[i]=encodeConstraintSATEncoder(This, getArrayBoolean(&constraint->inputs, i));
 114
 115         switch(constraint->op) {
 116         case L_AND:
 117                 return constraintAND(This->cnf, getSizeArrayBoolean(&constraint->inputs), array);
 118         case L_OR:
 119                 return constraintOR(This->cnf, getSizeArrayBoolean(&constraint->inputs), array);
 120         case L_NOT:
 121                 ASSERT( getSizeArrayBoolean(&constraint->inputs)==1);
 122                 return constraintNegate(array[0]);
 123         case L_XOR:
 124                 ASSERT( getSizeArrayBoolean(&constraint->inputs)==2);
 125                 return constraintXOR(This->cnf, array[0], array[1]);
 126         case L_IMPLIES:
 127                 ASSERT( getSizeArrayBoolean( &constraint->inputs)==2);
 128                 return constraintIMPLIES(This->cnf, array[0], array[1]);
 129         default:
 130                 model_print("Unhandled case in encodeLogicSATEncoder %u", constraint->op);
 131                 exit(-1);
 132         }
 133 }
 134
 135
 136 Edge encodeOrderSATEncoder(SATEncoder *This, BooleanOrder * constraint) {
 137         switch( constraint->order->type){
 138                 case PARTIAL:
 139                         return encodePartialOrderSATEncoder(This, constraint);
 140                 case TOTAL:
 141                         return encodeTotalOrderSATEncoder(This, constraint);
 142                 default:
 143                         ASSERT(0);
 144         }
 145         return E_BOGUS;
 146 }
 147
 148 Edge getPairConstraint(SATEncoder *This, HashTableOrderPair * table, OrderPair * pair) {
 149         bool negate = false;
 150         OrderPair flipped;
 151         if (pair->first > pair->second) {
 152                 negate=true;
 153                 flipped.first=pair->second;
 154                 flipped.second=pair->first;
 155                 pair = &flipped;
 156         }
 157         Edge constraint;
 158         if (!containsOrderPair(table, pair)) {
 159                 constraint = getNewVarSATEncoder(This);
 160                 OrderPair * paircopy = allocOrderPair(pair->first, pair->second, constraint);
 161                 putOrderPair(table, paircopy, paircopy);
 162         } else
 163                 constraint = getOrderPair(table, pair)->constraint;
 164         if (negate)
 165                 return constraintNegate(constraint);
 166         else
 167                 return constraint;
 168
 169 }
 170
 171 Edge encodeTotalOrderSATEncoder(SATEncoder *This, BooleanOrder * boolOrder){
 172         ASSERT(boolOrder->order->type == TOTAL);
 173         if(boolOrder->order->orderPairTable == NULL){
 174                 initializeOrderHashTable(boolOrder->order);
 175                 createAllTotalOrderConstraintsSATEncoder(This, boolOrder->order);
 176         }
 177         HashTableOrderPair* orderPairTable = boolOrder->order->orderPairTable;
 178         OrderPair pair={boolOrder->first, boolOrder->second, E_NULL};
 179         Edge constraint = getPairConstraint(This, orderPairTable, & pair);
 180         return constraint;
 181 }
 182
 183 void createAllTotalOrderConstraintsSATEncoder(SATEncoder* This, Order* order){
 184         ASSERT(order->type == TOTAL);
 185         VectorInt* mems = order->set->members;
 186         HashTableOrderPair* table = order->orderPairTable;
 187         uint size = getSizeVectorInt(mems);
 188         uint csize =0;
 189         for(uint i=0; i<size; i++){
 190                 uint64_t valueI = getVectorInt(mems, i);
 191                 for(uint j=i+1; j<size;j++){
 192                         uint64_t valueJ = getVectorInt(mems, j);
 193                         OrderPair pairIJ = {valueI, valueJ};
 194                         Edge constIJ=getPairConstraint(This, table, & pairIJ);
 195                         for(uint k=j+1; k<size; k++){
 196                                 uint64_t valueK = getVectorInt(mems, k);
 197                                 OrderPair pairJK = {valueJ, valueK};
 198                                 OrderPair pairIK = {valueI, valueK};
 199                                 Edge constIK = getPairConstraint(This, table, & pairIK);
 200                                 Edge constJK = getPairConstraint(This, table, & pairJK);
 201                                 addConstraintCNF(This->cnf, generateTransOrderConstraintSATEncoder(This, constIJ, constJK, constIK));
 202                         }
 203                 }
 204         }
 205 }
 206
 207 Edge getOrderConstraint(HashTableOrderPair *table, OrderPair *pair){
 208         ASSERT(pair->first!= pair->second);
 209         Edge constraint = getOrderPair(table, pair)->constraint;
 210         if(pair->first > pair->second)
 211                 return constraint;
 212         else
 213                 return constraintNegate(constraint);
 214 }
 215
 216 Edge generateTransOrderConstraintSATEncoder(SATEncoder *This, Edge constIJ,Edge constJK,Edge constIK){
 217         Edge carray[] = {constIJ, constJK, constraintNegate(constIK)};
 218         Edge loop1= constraintOR(This->cnf, 3, carray);
 219         Edge carray2[] = {constraintNegate(constIJ), constraintNegate(constJK), constIK};
 220         Edge loop2= constraintOR(This->cnf, 3, carray2 );
 221         return constraintAND2(This->cnf, loop1, loop2);
 222 }
 223
 224 Edge encodePartialOrderSATEncoder(SATEncoder *This, BooleanOrder * constraint){
 225         // FIXME: we can have this implementation for partial order. Basically,
 226         // we compute the transitivity between two order constraints specified by the client! (also can be used
 227         // when client specify sparse constraints for the total order!)
 228         ASSERT(constraint->order->type == PARTIAL);
 229 /*
 230         HashTableOrderPair* boolToConsts = boolOrder->order->boolsToConstraints;
 231         if( containsOrderPair(boolToConsts, boolOrder) ){
 232                 return getOrderPair(boolToConsts, boolOrder);
 233         } else {
 234                 Edge constraint = getNewVarSATEncoder(This);
 235                 putOrderPair(boolToConsts,boolOrder, constraint);
 236                 VectorBoolean* orderConstrs = &boolOrder->order->constraints;
 237                 uint size= getSizeVectorBoolean(orderConstrs);
 238                 for(uint i=0; i<size; i++){
 239                         ASSERT(GETBOOLEANTYPE( getVectorBoolean(orderConstrs, i)) == ORDERCONST );
 240                         BooleanOrder* tmp = (BooleanOrder*)getVectorBoolean(orderConstrs, i);
 241                         BooleanOrder* newBool;
 242                         Edge first, second;
 243                         if(tmp->second==boolOrder->first){
 244                                 newBool = (BooleanOrder*)allocBooleanOrder(tmp->order,tmp->first,boolOrder->second);
 245                                 first = encodeTotalOrderSATEncoder(This, tmp);
 246                                 second = constraint;
 247
 248                         }else if (boolOrder->second == tmp->first){
 249                                 newBool = (BooleanOrder*)allocBooleanOrder(tmp->order,boolOrder->first,tmp->second);
 250                                 first = constraint;
 251                                 second = encodeTotalOrderSATEncoder(This, tmp);
 252                         }else
 253                                 continue;
 254                         Edge transConstr= encodeTotalOrderSATEncoder(This, newBool);
 255                         generateTransOrderConstraintSATEncoder(This, first, second, transConstr );
 256                 }
 257                 return constraint;
 258         }
 259 */
 260         return E_BOGUS;
 261 }
 262
 263 Edge encodePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint) {
 264         switch(GETPREDICATETYPE(constraint->predicate) ){
 265                 case TABLEPRED:
 266                         return encodeTablePredicateSATEncoder(This, constraint);
 267                 case OPERATORPRED:
 268                         return encodeOperatorPredicateSATEncoder(This, constraint);
 269                 default:
 270                         ASSERT(0);
 271         }
 272         return E_BOGUS;
 273 }
 274
 275 Edge encodeTablePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 276         switch(constraint->encoding.type){
 277                 case ENUMERATEIMPLICATIONS:
 278                 case ENUMERATEIMPLICATIONSNEGATE:
 279                         return encodeEnumTablePredicateSATEncoder(This, constraint);
 280                 case CIRCUIT:
 281                         ASSERT(0);
 282                         break;
 283                 default:
 284                         ASSERT(0);
 285         }
 286         return E_BOGUS;
 287 }
 288
 289 Edge encodeEnumTablePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 290         VectorTableEntry* entries = &(((PredicateTable*)constraint->predicate)->table->entries);
 291         FunctionEncodingType encType = constraint->encoding.type;
 292         ArrayElement* inputs = &constraint->inputs;
 293         uint inputNum =getSizeArrayElement(inputs);
 294         //Encode all the inputs first ...
 295         for(uint i=0; i<inputNum; i++){
 296                 encodeElementSATEncoder(This, getArrayElement(inputs, i));
 297         }
 298
 299         uint size = getSizeVectorTableEntry(entries);
 300         bool generateNegation = encType == ENUMERATEIMPLICATIONSNEGATE;
 301         Edge constraints[size];
 302         for(uint i=0; i<size; i++){
 303                 TableEntry* entry = getVectorTableEntry(entries, i);
 304                 if(generateNegation == entry->output) {
 305                         //Skip the irrelevant entries
 306                         continue;
 307                 }
 308                 Edge carray[inputNum];
 309                 for(uint j=0; j<inputNum; j++){
 310                         Element* el = getArrayElement(inputs, j);
 311                         carray[j] = getElementValueConstraint(This, el, entry->inputs[j]);
 312                 }
 313                 constraints[i]=constraintAND(This->cnf, inputNum, carray);
 314         }
 315         Edge result=constraintOR(This->cnf, size, constraints);
 316
 317         return generateNegation ? result: constraintNegate(result);
 318 }
 319
 320 Edge encodeOperatorPredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 321         switch(constraint->encoding.type){
 322                 case ENUMERATEIMPLICATIONS:
 323                         return encodeEnumOperatorPredicateSATEncoder(This, constraint);
 324                 case CIRCUIT:
 325                         ASSERT(0);
 326                         break;
 327                 default:
 328                         ASSERT(0);
 329         }
 330         return E_BOGUS;
 331 }
 332
 333 Edge encodeEnumOperatorPredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 334         ASSERT(GETPREDICATETYPE(constraint->predicate)==OPERATORPRED);
 335         PredicateOperator* predicate = (PredicateOperator*)constraint->predicate;
 336         ASSERT(predicate->op == EQUALS); //For now, we just only support equals
 337         //getting maximum size of in common elements between two sets!
 338         uint size=getSizeVectorInt( getArraySet( &predicate->domains, 0)->members);
 339         uint64_t commonElements [size];
 340         getEqualitySetIntersection(predicate, &size, commonElements);
 341         Edge  carray[size];
 342         Element* elem1 = getArrayElement( &constraint->inputs, 0);
 343         Element* elem2 = getArrayElement( &constraint->inputs, 1);
 344         encodeElementSATEncoder(This,elem1);
 345         encodeElementSATEncoder(This, elem2);
 346
 347         for(uint i=0; i<size; i++){
 348                 Edge arg1 = getElementValueConstraint(This, elem1, commonElements[i]);
 349                 Edge arg2 = getElementValueConstraint(This, elem2, commonElements[i]);
 350                 carray[i] =  constraintAND2(This->cnf, arg1, arg2);
 351         }
 352         //FIXME: the case when there is no intersection ....
 353         return constraintOR(This->cnf, size, carray);
 354 }
 355
 356 void encodeElementSATEncoder(SATEncoder* encoder, Element *This){
 357         switch( GETELEMENTTYPE(This) ){
 358                 case ELEMFUNCRETURN:
 359                         addConstraintCNF(encoder->cnf, encodeElementFunctionSATEncoder(encoder, (ElementFunction*) This));
 360                         break;
 361                 case ELEMSET:
 362                         return;
 363                 default:
 364                         ASSERT(0);
 365         }
 366 }
 367
 368 Edge encodeElementFunctionSATEncoder(SATEncoder* encoder, ElementFunction *This){
 369         switch(GETFUNCTIONTYPE(This->function)){
 370                 case TABLEFUNC:
 371                         return encodeTableElementFunctionSATEncoder(encoder, This);
 372                 case OPERATORFUNC:
 373                         return encodeOperatorElementFunctionSATEncoder(encoder, This);
 374                 default:
 375                         ASSERT(0);
 376         }
 377         return E_BOGUS;
 378 }
 379
 380 Edge encodeTableElementFunctionSATEncoder(SATEncoder* encoder, ElementFunction* This){
 381         switch(getElementFunctionEncoding(This)->type){
 382                 case ENUMERATEIMPLICATIONS:
 383                         return encodeEnumTableElemFunctionSATEncoder(encoder, This);
 384                         break;
 385                 case CIRCUIT:
 386                         ASSERT(0);
 387                         break;
 388                 default:
 389                         ASSERT(0);
 390         }
 391         return E_BOGUS;
 392 }
 393
 394 Edge encodeOperatorElementFunctionSATEncoder(SATEncoder* encoder, ElementFunction* This){
 395         ASSERT(GETFUNCTIONTYPE(This->function) == OPERATORFUNC);
 396         ASSERT(getSizeArrayElement(&This->inputs)==2 );
 397         Element* elem1 = getArrayElement(&This->inputs,0);
 398         Element* elem2 = getArrayElement(&This->inputs,1);
 399         encodeElementSATEncoder(encoder, elem1);
 400         encodeElementSATEncoder(encoder , elem2);
 401
 402         ElementEncoding* elemEnc1 = getElementEncoding( getArrayElement(&This->inputs,0) );
 403         ElementEncoding* elemEnc2 = getElementEncoding( getArrayElement(&This->inputs,1) );
 404         Edge carray[elemEnc1->encArraySize*elemEnc2->encArraySize];
 405         uint size=0;
 406         Edge overFlowConstraint = ((BooleanVar*) This->overflowstatus)->var;
 407         for(uint i=0; i<elemEnc1->encArraySize; i++){
 408                 if(isinUseElement(elemEnc1, i)){
 409                         for( uint j=0; j<elemEnc2->encArraySize; j++){
 410                                 if(isinUseElement(elemEnc2, j)){
 411                                         uint64_t result= applyFunctionOperator((FunctionOperator*)This->function,elemEnc1->encodingArray[i],
 412                                                 elemEnc2->encodingArray[j]);
 413                                         bool isInRange = isInRangeFunction((FunctionOperator*)This->function, result);
 414
 415                                         //FIXME: instead of getElementValueConstraint, it might be useful to have another function
 416                                         // that doesn't iterate over encodingArray and treats more efficient ...
 417                                         Edge valConstrIn1 = getElementValueConstraint(encoder, elemEnc1->element, elemEnc1->encodingArray[i]);
 418                                         Edge valConstrIn2 = getElementValueConstraint(encoder, elemEnc2->element, elemEnc2->encodingArray[j]);
 419                                         Edge valConstrOut = getElementValueConstraint(encoder, (Element*) This, result);
 420                                         if(edgeIsNull(valConstrOut))
 421                                                 continue; //FIXME:Should talk to brian about it!
 422                                         Edge OpConstraint = constraintIMPLIES(encoder->cnf, constraintAND2(encoder->cnf, valConstrIn1, valConstrIn2), valConstrOut);
 423                                         switch( ((FunctionOperator*)This->function)->overflowbehavior ){
 424                                                 case IGNORE:
 425                                                         if(isInRange){
 426                                                                 carray[size++] = OpConstraint;
 427                                                         }
 428                                                         break;
 429                                                 case WRAPAROUND:
 430                                                         carray[size++] = OpConstraint;
 431                                                         break;
 432                                                 case FLAGFORCESOVERFLOW:
 433                                                         if(isInRange){
 434                                                                 Edge const1 = constraintIMPLIES(encoder->cnf, constraintAND2(encoder->cnf, valConstrIn1, valConstrIn2), constraintNegate(overFlowConstraint));
 435                                                                 carray[size++] = constraintAND2(encoder->cnf, const1, OpConstraint);
 436                                                         }
 437                                                         break;
 438                                                 case OVERFLOWSETSFLAG:
 439                                                         if(isInRange){
 440                                                                 carray[size++] = OpConstraint;
 441                                                         } else{
 442                                                                 carray[size++] = constraintIMPLIES(encoder->cnf, constraintAND2(encoder->cnf, valConstrIn1, valConstrIn2), overFlowConstraint);
 443                                                         }
 444                                                         break;
 445                                                 case FLAGIFFOVERFLOW:
 446                                                         if(isInRange){
 447                                                                 Edge const1 = constraintIMPLIES(encoder->cnf, constraintAND2(encoder->cnf, valConstrIn1, valConstrIn2), constraintNegate(overFlowConstraint));
 448                                                                 carray[size++] = constraintAND2(encoder->cnf, const1, OpConstraint);
 449                                                         } else {
 450                                                                 carray[size++] = constraintIMPLIES(encoder->cnf, constraintAND2(encoder->cnf, valConstrIn1, valConstrIn2), overFlowConstraint);
 451                                                         }
 452                                                         break;
 453                                                 case NOOVERFLOW:
 454                                                         if(!isInRange){
 455                                                                 ASSERT(0);
 456                                                         }
 457                                                         carray[size++] = OpConstraint;
 458                                                         break;
 459                                                 default:
 460                                                         ASSERT(0);
 461                                         }
 462
 463                                 }
 464                         }
 465                 }
 466         }
 467         return constraintAND(encoder->cnf, size, carray);
 468 }
 469
 470 Edge encodeEnumTableElemFunctionSATEncoder(SATEncoder* encoder, ElementFunction* This){
 471         ASSERT(GETFUNCTIONTYPE(This->function)==TABLEFUNC);
 472         ArrayElement* elements= &This->inputs;
 473         Table* table = ((FunctionTable*) (This->function))->table;
 474         uint size = getSizeVectorTableEntry(&table->entries);
 475         Edge constraints[size]; //FIXME: should add a space for the case that didn't match any entries
 476         for(uint i=0; i<size; i++) {
 477                 TableEntry* entry = getVectorTableEntry(&table->entries, i);
 478                 uint inputNum = getSizeArrayElement(elements);
 479                 Edge carray[inputNum];
 480                 for(uint j=0; j<inputNum; j++){
 481                         Element* el= getArrayElement(elements, j);
 482                         carray[j] = getElementValueConstraint(encoder, el, entry->inputs[j]);
 483                 }
 484                 Edge output = getElementValueConstraint(encoder, (Element*)This, entry->output);
 485                 Edge row= constraintIMPLIES(encoder->cnf, constraintAND(encoder->cnf, inputNum, carray), output);
 486                 constraints[i]=row;
 487         }
 488         return constraintOR(encoder->cnf, size, constraints);
 489 }