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         return This;
  20 }
  21
  22 void deleteSATEncoder(SATEncoder *This) {
  23         ourfree(This);
  24 }
  25
  26 Constraint * getElementValueConstraint(SATEncoder* encoder,Element* This, uint64_t value) {
  27         generateElementEncodingVariables(encoder, getElementEncoding(This));
  28         switch(getElementEncoding(This)->type){
  29                 case ONEHOT:
  30                         ASSERT(0);
  31                         break;
  32                 case UNARY:
  33                         ASSERT(0);
  34                         break;
  35                 case BINARYINDEX:
  36                         return getElementValueBinaryIndexConstraint(This, value);
  37                         break;
  38                 case ONEHOTBINARY:
  39                         ASSERT(0);
  40                         break;
  41                 case BINARYVAL:
  42                         ASSERT(0);
  43                         break;
  44                 default:
  45                         ASSERT(0);
  46                         break;
  47         }
  48         return NULL;
  49 }
  50 Constraint * getElementValueBinaryIndexConstraint(Element* This, uint64_t value) {
  51         ASTNodeType type = GETELEMENTTYPE(This);
  52         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  53         ElementEncoding* elemEnc = getElementEncoding(This);
  54         for(uint i=0; i<elemEnc->encArraySize; i++){
  55                 if( isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value){
  56                         return generateBinaryConstraint(elemEnc->numVars,
  57                                 elemEnc->variables, i);
  58                 }
  59         }
  60         return NULL;
  61 }
  62
  63 void encodeAllSATEncoder(CSolver *csolver, SATEncoder * This) {
  64         VectorBoolean *constraints=csolver->constraints;
  65         uint size=getSizeVectorBoolean(constraints);
  66         for(uint i=0;i<size;i++) {
  67                 Boolean *constraint=getVectorBoolean(constraints, i);
  68                 Constraint* c= encodeConstraintSATEncoder(This, constraint);
  69                 printConstraint(c);
  70                 model_print("\n");
  71         }
  72 }
  73
  74 Constraint * encodeConstraintSATEncoder(SATEncoder *This, Boolean *constraint) {
  75         switch(GETBOOLEANTYPE(constraint)) {
  76         case ORDERCONST:
  77                 return encodeOrderSATEncoder(This, (BooleanOrder *) constraint);
  78         case BOOLEANVAR:
  79                 return encodeVarSATEncoder(This, (BooleanVar *) constraint);
  80         case LOGICOP:
  81                 return encodeLogicSATEncoder(This, (BooleanLogic *) constraint);
  82         case PREDICATEOP:
  83                 return encodePredicateSATEncoder(This, (BooleanPredicate *) constraint);
  84         default:
  85                 model_print("Unhandled case in encodeConstraintSATEncoder %u", GETBOOLEANTYPE(constraint));
  86                 exit(-1);
  87         }
  88 }
  89
  90 void getArrayNewVarsSATEncoder(SATEncoder* encoder, uint num, Constraint **carray) {
  91         for(uint i=0;i<num;i++)
  92                 carray[i]=getNewVarSATEncoder(encoder);
  93 }
  94
  95 Constraint * getNewVarSATEncoder(SATEncoder *This) {
  96         Constraint * var=allocVarConstraint(VAR, This->varcount);
  97         Constraint * varneg=allocVarConstraint(NOTVAR, This->varcount++);
  98         setNegConstraint(var, varneg);
  99         setNegConstraint(varneg, var);
 100         return var;
 101 }
 102
 103 Constraint * encodeVarSATEncoder(SATEncoder *This, BooleanVar * constraint) {
 104         if (constraint->var == NULL) {
 105                 constraint->var=getNewVarSATEncoder(This);
 106         }
 107         return constraint->var;
 108 }
 109
 110 Constraint * encodeLogicSATEncoder(SATEncoder *This, BooleanLogic * constraint) {
 111         Constraint * 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 allocArrayConstraint(AND, getSizeArrayBoolean(&constraint->inputs), array);
 118         case L_OR:
 119                 return allocArrayConstraint(OR, getSizeArrayBoolean(&constraint->inputs), array);
 120         case L_NOT:
 121                 ASSERT( getSizeArrayBoolean(&constraint->inputs)==1);
 122                 return negateConstraint(array[0]);
 123         case L_XOR: {
 124                 ASSERT( getSizeArrayBoolean(&constraint->inputs)==2);
 125                 Constraint * nleft=negateConstraint(cloneConstraint(array[0]));
 126                 Constraint * nright=negateConstraint(cloneConstraint(array[1]));
 127                 return allocConstraint(OR,
 128                                                                                                          allocConstraint(AND, array[0], nright),
 129                                                                                                          allocConstraint(AND, nleft, array[1]));
 130         }
 131         case L_IMPLIES:
 132                 ASSERT( getSizeArrayBoolean( &constraint->inputs)==2);
 133                 return allocConstraint(IMPLIES, array[0], array[1]);
 134         default:
 135                 model_print("Unhandled case in encodeLogicSATEncoder %u", constraint->op);
 136                 exit(-1);
 137         }
 138 }
 139
 140
 141 Constraint * encodeOrderSATEncoder(SATEncoder *This, BooleanOrder * constraint) {
 142         switch( constraint->order->type){
 143                 case PARTIAL:
 144                         return encodePartialOrderSATEncoder(This, constraint);
 145                 case TOTAL:
 146                         return encodeTotalOrderSATEncoder(This, constraint);
 147                 default:
 148                         ASSERT(0);
 149         }
 150         return NULL;
 151 }
 152
 153 Constraint * getPairConstraint(SATEncoder *This, HashTableBoolConst * table, OrderPair * pair) {
 154         bool negate = false;
 155         OrderPair flipped;
 156         if (pair->first > pair->second) {
 157                 negate=true;
 158                 flipped.first=pair->second;
 159                 flipped.second=pair->first;
 160                 pair = &flipped;
 161         }
 162         Constraint * constraint;
 163         if (!containsBoolConst(table, pair)) {
 164                 constraint = getNewVarSATEncoder(This);
 165                 OrderPair * paircopy = allocOrderPair(pair->first, pair->second);
 166                 putBoolConst(table, paircopy, constraint);
 167         } else
 168                 constraint = getBoolConst(table, pair);
 169         if (negate)
 170                 return negateConstraint(constraint);
 171         else
 172                 return constraint;
 173
 174 }
 175
 176 Constraint * encodeTotalOrderSATEncoder(SATEncoder *This, BooleanOrder * boolOrder){
 177         ASSERT(boolOrder->order->type == TOTAL);
 178         HashTableBoolConst* boolToConsts = boolOrder->order->boolsToConstraints;
 179         OrderPair pair={boolOrder->first, boolOrder->second};
 180         Constraint* constraint = getPairConstraint(This, boolToConsts, & pair);
 181         ASSERT(constraint != NULL);
 182         return constraint;
 183 }
 184
 185 void createAllTotalOrderConstraintsSATEncoder(SATEncoder* This, Order* order){
 186         ASSERT(order->type == TOTAL);
 187         VectorInt* mems = order->set->members;
 188         HashTableBoolConst* table = order->boolsToConstraints;
 189         uint size = getSizeVectorInt(mems);
 190         for(uint i=0; i<size; i++){
 191                 uint64_t valueI = getVectorInt(mems, i);
 192                 for(uint j=i+1; j<size;j++){
 193                         uint64_t valueJ = getVectorInt(mems, j);
 194                         OrderPair pairIJ = {valueI, valueJ};
 195                         Constraint* constIJ=getPairConstraint(This, table, & pairIJ);
 196                         for(uint k=j+1; k<size; k++){
 197                                 uint64_t valueK = getVectorInt(mems, k);
 198                                 OrderPair pairJK = {valueJ, valueK};
 199                                 OrderPair pairIK = {valueI, valueK};
 200                                 Constraint* constIK = getPairConstraint(This, table, & pairIK);
 201                                 Constraint* constJK = getPairConstraint(This, table, & pairJK);
 202                                 generateTransOrderConstraintSATEncoder(This, constIJ, constJK, constIK);
 203                         }
 204                 }
 205         }
 206 }
 207
 208 Constraint* getOrderConstraint(HashTableBoolConst *table, OrderPair *pair){
 209         ASSERT(pair->first!= pair->second);
 210         Constraint* constraint= getBoolConst(table, pair);
 211         ASSERT(constraint!= NULL);
 212         if(pair->first > pair->second)
 213                 return constraint;
 214         else
 215                 return negateConstraint(constraint);
 216 }
 217
 218 Constraint * generateTransOrderConstraintSATEncoder(SATEncoder *This, Constraint *constIJ,Constraint *constJK,Constraint *constIK){
 219         //FIXME: first we should add the the constraint to the satsolver!
 220         ASSERT(constIJ!= NULL && constJK != NULL && constIK != NULL);
 221         Constraint *carray[] = {constIJ, constJK, negateConstraint(constIK)};
 222         Constraint * loop1= allocArrayConstraint(OR, 3, carray);
 223         Constraint * carray2[] = {negateConstraint(constIJ), negateConstraint(constJK), constIK};
 224         Constraint * loop2= allocArrayConstraint(OR, 3,carray2 );
 225         return allocConstraint(AND, loop1, loop2);
 226 }
 227
 228 Constraint * encodePartialOrderSATEncoder(SATEncoder *This, BooleanOrder * constraint){
 229         // FIXME: we can have this implementation for partial order. Basically,
 230         // we compute the transitivity between two order constraints specified by the client! (also can be used
 231         // when client specify sparse constraints for the total order!)
 232         ASSERT(constraint->order->type == PARTIAL);
 233 /*
 234         HashTableBoolConst* boolToConsts = boolOrder->order->boolsToConstraints;
 235         if( containsBoolConst(boolToConsts, boolOrder) ){
 236                 return getBoolConst(boolToConsts, boolOrder);
 237         } else {
 238                 Constraint* constraint = getNewVarSATEncoder(This);
 239                 putBoolConst(boolToConsts,boolOrder, constraint);
 240                 VectorBoolean* orderConstrs = &boolOrder->order->constraints;
 241                 uint size= getSizeVectorBoolean(orderConstrs);
 242                 for(uint i=0; i<size; i++){
 243                         ASSERT(GETBOOLEANTYPE( getVectorBoolean(orderConstrs, i)) == ORDERCONST );
 244                         BooleanOrder* tmp = (BooleanOrder*)getVectorBoolean(orderConstrs, i);
 245                         BooleanOrder* newBool;
 246                         Constraint* first, *second;
 247                         if(tmp->second==boolOrder->first){
 248                                 newBool = (BooleanOrder*)allocBooleanOrder(tmp->order,tmp->first,boolOrder->second);
 249                                 first = encodeTotalOrderSATEncoder(This, tmp);
 250                                 second = constraint;
 251
 252                         }else if (boolOrder->second == tmp->first){
 253                                 newBool = (BooleanOrder*)allocBooleanOrder(tmp->order,boolOrder->first,tmp->second);
 254                                 first = constraint;
 255                                 second = encodeTotalOrderSATEncoder(This, tmp);
 256                         }else
 257                                 continue;
 258                         Constraint* transConstr= encodeTotalOrderSATEncoder(This, newBool);
 259                         generateTransOrderConstraintSATEncoder(This, first, second, transConstr );
 260                 }
 261                 return constraint;
 262         }
 263 */
 264         return NULL;
 265 }
 266
 267 Constraint * encodePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint) {
 268         switch(GETPREDICATETYPE(constraint->predicate) ){
 269                 case TABLEPRED:
 270                         return encodeTablePredicateSATEncoder(This, constraint);
 271                 case OPERATORPRED:
 272                         return encodeOperatorPredicateSATEncoder(This, constraint);
 273                 default:
 274                         ASSERT(0);
 275         }
 276         return NULL;
 277 }
 278
 279 Constraint * encodeTablePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 280         switch(constraint->encoding.type){
 281                 case ENUMERATEIMPLICATIONS:
 282                 case ENUMERATEIMPLICATIONSNEGATE:
 283                         return encodeEnumTablePredicateSATEncoder(This, constraint);
 284                 case CIRCUIT:
 285                         ASSERT(0);
 286                         break;
 287                 default:
 288                         ASSERT(0);
 289         }
 290         return NULL;
 291 }
 292
 293 Constraint * encodeEnumTablePredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 294         VectorTableEntry* entries = &(((PredicateTable*)constraint->predicate)->table->entries);
 295         FunctionEncodingType encType = constraint->encoding.type;
 296         uint size = getSizeVectorTableEntry(entries);
 297         Constraint* constraints[size];
 298         for(uint i=0; i<size; i++){
 299                 TableEntry* entry = getVectorTableEntry(entries, i);
 300                 if(encType==ENUMERATEIMPLICATIONS && entry->output!= true)
 301                         continue;
 302                 else if(encType==ENUMERATEIMPLICATIONSNEGATE && entry->output !=false)
 303                         continue;
 304                 ArrayElement* inputs = &constraint->inputs;
 305                 uint inputNum =getSizeArrayElement(inputs);
 306                 Constraint* carray[inputNum];
 307                 for(uint j=0; j<inputNum; j++){
 308                         Element* el = getArrayElement(inputs, j);
 309                         if( GETELEMENTTYPE(el) == ELEMFUNCRETURN)
 310                                 encodeFunctionElementSATEncoder(This, (ElementFunction*) el);
 311                         carray[j] = getElementValueConstraint(This,el, entry->inputs[j]);
 312                         ASSERT(carray[j]!= NULL);
 313                 }
 314                 constraints[i]=allocArrayConstraint(AND, inputNum, carray);
 315         }
 316         Constraint* result= allocArrayConstraint(OR, size, constraints);
 317         //FIXME: if it didn't match with any entry
 318         return encType==ENUMERATEIMPLICATIONS? result: negateConstraint(result);
 319 }
 320
 321 Constraint * encodeOperatorPredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 322         switch(constraint->encoding.type){
 323                 case ENUMERATEIMPLICATIONS:
 324                         return encodeEnumOperatorPredicateSATEncoder(This, constraint);
 325                 case CIRCUIT:
 326                         ASSERT(0);
 327                         break;
 328                 default:
 329                         ASSERT(0);
 330         }
 331         return NULL;
 332 }
 333
 334 Constraint * encodeEnumOperatorPredicateSATEncoder(SATEncoder * This, BooleanPredicate * constraint){
 335         ASSERT(GETPREDICATETYPE(constraint->predicate)==OPERATORPRED);
 336         PredicateOperator* predicate = (PredicateOperator*)constraint->predicate;
 337         ASSERT(predicate->op == EQUALS); //For now, we just only support equals
 338         //getting maximum size of in common elements between two sets!
 339         uint size=getSizeVectorInt( getArraySet( &predicate->domains, 0)->members);
 340         uint64_t commonElements [size];
 341         getEqualitySetIntersection(predicate, &size, commonElements);
 342         Constraint*  carray[size];
 343         Element* elem1 = getArrayElement( &constraint->inputs, 0);
 344         if( GETELEMENTTYPE(elem1) == ELEMFUNCRETURN)
 345                 encodeFunctionElementSATEncoder(This, (ElementFunction*) elem1);
 346         Element* elem2 = getArrayElement( &constraint->inputs, 1);
 347         if( GETELEMENTTYPE(elem2) == ELEMFUNCRETURN)
 348                 encodeFunctionElementSATEncoder(This, (ElementFunction*) elem2);
 349         for(uint i=0; i<size; i++){
 350                 Constraint* arg1 = getElementValueConstraint(This, elem1, commonElements[i]);
 351                 ASSERT(arg1!=NULL);
 352                 Constraint* arg2 = getElementValueConstraint(This, elem2, commonElements[i]);
 353                 ASSERT(arg2 != NULL);
 354                 carray[i] =  allocConstraint(AND, arg1, arg2);
 355         }
 356         //FIXME: the case when there is no intersection ....
 357         return allocArrayConstraint(OR, size, carray);
 358 }
 359
 360 Constraint* encodeFunctionElementSATEncoder(SATEncoder* encoder, ElementFunction *This){
 361         switch(GETFUNCTIONTYPE(This->function)){
 362                 case TABLEFUNC:
 363                         return encodeTableElementFunctionSATEncoder(encoder, This);
 364                 case OPERATORFUNC:
 365                         return encodeOperatorElementFunctionSATEncoder(encoder, This);
 366                 default:
 367                         ASSERT(0);
 368         }
 369         return NULL;
 370 }
 371
 372 Constraint* encodeTableElementFunctionSATEncoder(SATEncoder* encoder, ElementFunction* This){
 373         switch(getElementFunctionEncoding(This)->type){
 374                 case ENUMERATEIMPLICATIONS:
 375                         return encodeEnumTableElemFunctionSATEncoder(encoder, This);
 376                         break;
 377                 case CIRCUIT:
 378                         ASSERT(0);
 379                         break;
 380                 default:
 381                         ASSERT(0);
 382         }
 383         return NULL;
 384 }
 385
 386 Constraint* encodeOperatorElementFunctionSATEncoder(SATEncoder* encoder, ElementFunction* This){
 387         ASSERT(GETFUNCTIONTYPE(This->function) == OPERATORFUNC);
 388         ASSERT(getSizeArrayElement(&This->inputs)==2 );
 389         ElementEncoding* elem1 = getElementEncoding( getArrayElement(&This->inputs,0) );
 390         generateElementEncodingVariables(encoder, elem1);
 391         ElementEncoding* elem2 = getElementEncoding( getArrayElement(&This->inputs,1) );
 392         generateElementEncodingVariables(encoder, elem2);
 393         Constraint* carray[elem1->encArraySize*elem2->encArraySize];
 394         uint size=0;
 395         Constraint* overFlowConstraint = ((BooleanVar*) This->overflowstatus)->var;
 396         for(uint i=0; i<elem1->encArraySize; i++){
 397                 if(isinUseElement(elem1, i)){
 398                         for(uint j=0; j<elem2->encArraySize; j++){
 399                                 if(isinUseElement(elem2, j)){
 400                                         bool isInRange = false, hasOverFlow=false;
 401                                         uint64_t result= applyFunctionOperator((FunctionOperator*)This->function,elem1->encodingArray[i],
 402                                                 elem2->encodingArray[j], &isInRange, &hasOverFlow);
 403                                         if(!isInRange)
 404                                                 break; // Ignoring the cases that result of operation doesn't exist in the code.
 405                                         //FIXME: instead of getElementValueConstraint, it might be useful to have another function
 406                                         // that doesn't iterate over encodingArray and treats more efficient ...
 407                                         Constraint* and1 = getElementValueConstraint(encoder, elem1->element, elem1->encodingArray[i]);
 408                                         ASSERT(and1 != NULL);
 409                                         Constraint* and2 = getElementValueConstraint(encoder, elem2->element, elem2->encodingArray[j]);
 410                                         ASSERT(and2 != NULL);
 411                                         Constraint* imply2 = getElementValueConstraint(encoder, (Element*) This, result);
 412                                         ASSERT(imply2 != NULL);
 413                                         Constraint* constraint = allocConstraint(IMPLIES,
 414                                                 allocConstraint(AND, and1, and2) , imply2);
 415                                         switch( ((FunctionOperator*)This->function)->overflowbehavior ){
 416                                                 case IGNORE:
 417                                                         if(!hasOverFlow){
 418                                                                 carray[size++] = constraint;
 419                                                         }
 420                                                         break;
 421                                                 case WRAPAROUND:
 422                                                         carray[size++] = constraint;
 423                                                         break;
 424                                                 case FLAGFORCESOVERFLOW:
 425                                                         if(hasOverFlow){
 426                                                                 Constraint* const1 = allocConstraint(IMPLIES, overFlowConstraint,
 427                                                                                 allocConstraint(AND, getElementValueConstraint(encoder, elem1->element, elem1->encodingArray[i]),
 428                                                                                 getElementValueConstraint(encoder, elem2->element, elem2->encodingArray[j])));
 429                                                                 carray[size++] = allocConstraint(AND, const1, constraint);
 430                                                         }
 431                                                         break;
 432                                                 case OVERFLOWSETSFLAG:
 433                                                         if(hasOverFlow){
 434                                                                 Constraint* const1 = allocConstraint(IMPLIES, allocConstraint(AND, getElementValueConstraint(encoder, elem1->element, elem1->encodingArray[i]),
 435                                                                                 getElementValueConstraint(encoder, elem2->element, elem2->encodingArray[j])), overFlowConstraint);
 436                                                                 carray[size++] = allocConstraint(AND, const1, constraint);
 437                                                         } else
 438                                                                 carray[size++] = constraint;
 439                                                         break;
 440                                                 case FLAGIFFOVERFLOW:
 441                                                         if(!hasOverFlow){
 442                                                                 carray[size++] = constraint;
 443                                                         }else{
 444                                                                 Constraint* const1 = allocConstraint(IMPLIES, overFlowConstraint,
 445                                                                                 allocConstraint(AND, getElementValueConstraint(encoder, elem1->element, elem1->encodingArray[i]),
 446                                                                                 getElementValueConstraint(encoder, elem2->element, elem2->encodingArray[j])));
 447                                                                 Constraint* const2 = allocConstraint(IMPLIES, allocConstraint(AND, getElementValueConstraint(encoder, elem1->element, elem1->encodingArray[i]),
 448                                                                                 getElementValueConstraint(encoder, elem2->element, elem2->encodingArray[j])), overFlowConstraint);
 449                                                                 Constraint* res [] = {const1, const2, constraint};
 450                                                                 carray[size++] = allocArrayConstraint(AND, 3, res);
 451                                                         }
 452                                                         break;
 453                                                 case NOOVERFLOW:
 454                                                         if(hasOverFlow){
 455                                                                 ASSERT(0);
 456                                                         }
 457                                                         carray[size++] = constraint;
 458                                                         break;
 459                                                 default:
 460                                                         ASSERT(0);
 461                                         }
 462
 463                                 }
 464                         }
 465                 }
 466         }
 467         return allocArrayConstraint(AND, size, carray);
 468 }
 469
 470 Constraint* 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         Constraint* 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                 Constraint* 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                         ASSERT(carray[j]!= NULL);
 484                 }
 485                 Constraint* output = getElementValueConstraint(encoder, (Element*)This, entry->output);
 486                 ASSERT(output!= NULL);
 487                 Constraint* row= allocConstraint(IMPLIES, allocArrayConstraint(AND, inputNum, carray), output);
 488                 constraints[i]=row;
 489         }
 490         Constraint* result = allocArrayConstraint(OR, size, constraints);
 491         return result;
 492 }