src/Backend/satelemencoder.c

   1 #include "satencoder.h"
   2 #include "structs.h"
   3 #include "common.h"
   4 #include "ops.h"
   5 #include "element.h"
   6
   7 Edge getElementValueConstraint(SATEncoder* This, Element* elem, uint64_t value) {
   8         switch(getElementEncoding(elem)->type){
   9                 case ONEHOT:
  10                         return getElementValueOneHotConstraint(This, elem, value);
  11                 case UNARY:
  12                         return getElementValueUnaryConstraint(This, elem, value);
  13                 case BINARYINDEX:
  14                         return getElementValueBinaryIndexConstraint(This, elem, value);
  15                 case ONEHOTBINARY:
  16                         ASSERT(0);
  17                         break;
  18                 case BINARYVAL:
  19                         return getElementValueBinaryValueConstraint(This, elem, value);
  20                         break;
  21                 default:
  22                         ASSERT(0);
  23                         break;
  24         }
  25         return E_BOGUS;
  26 }
  27
  28 Edge getElementValueBinaryIndexConstraint(SATEncoder * This, Element* elem, uint64_t value) {
  29         ASTNodeType type = GETELEMENTTYPE(elem);
  30         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  31         ElementEncoding* elemEnc = getElementEncoding(elem);
  32         for(uint i=0; i<elemEnc->encArraySize; i++){
  33                 if(isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value) {
  34                         return generateBinaryConstraint(This->cnf, elemEnc->numVars, elemEnc->variables, i);
  35                 }
  36         }
  37         return E_BOGUS;
  38 }
  39
  40 Edge getElementValueOneHotConstraint(SATEncoder * This, Element* elem, uint64_t value) {
  41         ASTNodeType type = GETELEMENTTYPE(elem);
  42         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  43         ElementEncoding* elemEnc = getElementEncoding(elem);
  44         for(uint i=0; i<elemEnc->encArraySize; i++){
  45                 if (isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value) {
  46                         return elemEnc->variables[i];
  47                 }
  48         }
  49         return E_BOGUS;
  50 }
  51
  52 Edge getElementValueUnaryConstraint(SATEncoder * This, Element* elem, uint64_t value) {
  53         ASTNodeType type = GETELEMENTTYPE(elem);
  54         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  55         ElementEncoding* elemEnc = getElementEncoding(elem);
  56         for(uint i=0; i<elemEnc->encArraySize; i++){
  57                 if (isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value) {
  58                         if ((i+1)==elemEnc->encArraySize)
  59                                 return elemEnc->variables[i];
  60                         else
  61                                 return constraintAND2(This->cnf, elemEnc->variables[i], constraintNegate(elemEnc->variables[i+1]));
  62                 }
  63         }
  64         return E_BOGUS;
  65 }
  66
  67 Edge getElementValueBinaryValueConstraint(SATEncoder * This, Element* element, uint64_t value){
  68         ASTNodeType type = GETELEMENTTYPE(element);
  69         ASSERT(type == ELEMSET || type == ELEMFUNCRETURN);
  70         ElementEncoding* elemEnc = getElementEncoding(element);
  71         for(uint i=0; i<elemEnc->encArraySize; i++){
  72                 if(isinUseElement(elemEnc, i) && elemEnc->encodingArray[i]==value) {
  73                         return generateBinaryConstraint(This->cnf, elemEnc->numVars, elemEnc->variables, value);
  74                         // This constraint can be generated right away without iterating over encodingArray
  75                         // but we need to make sure that element with that value is in use ...
  76                 }
  77         }
  78         return E_BOGUS;
  79 }
  80
  81 void allocElementConstraintVariables(ElementEncoding* This, uint numVars) {
  82         This->numVars = numVars;
  83         This->variables = ourmalloc(sizeof(Edge) * numVars);
  84 }
  85
  86 void generateBinaryValueEncodingVars(SATEncoder* This, ElementEncoding* encoding){
  87         ASSERT(encoding->type==BINARYVAL);
  88         allocElementConstraintVariables(encoding, getMaximumBitsBinaryValueEncodingVars(encoding));
  89         getArrayNewVarsSATEncoder(This, encoding->numVars, encoding->variables);
  90 }
  91
  92 void generateBinaryIndexEncodingVars(SATEncoder *This, ElementEncoding *encoding) {
  93         ASSERT(encoding->type==BINARYINDEX);
  94         allocElementConstraintVariables(encoding, NUMBITS(encoding->encArraySize-1));
  95         getArrayNewVarsSATEncoder(This, encoding->numVars, encoding->variables);
  96 }
  97
  98 void generateOneHotEncodingVars(SATEncoder *This, ElementEncoding *encoding) {
  99         allocElementConstraintVariables(encoding, encoding->encArraySize);
 100         getArrayNewVarsSATEncoder(This, encoding->numVars, encoding->variables);
 101         for(uint i=0;i<encoding->numVars;i++) {
 102                 for(uint j=0;j<encoding->numVars;j++) {
 103                         addConstraintCNF(This->cnf, constraintIMPLIES(This->cnf, encoding->variables[i], constraintNegate(encoding->variables[j])));
 104                 }
 105         }
 106         addConstraintCNF(This->cnf, constraintOR(This->cnf, encoding->numVars, encoding->variables));
 107 }
 108
 109 void generateUnaryEncodingVars(SATEncoder *This, ElementEncoding *encoding) {
 110         allocElementConstraintVariables(encoding, encoding->encArraySize);
 111         getArrayNewVarsSATEncoder(This, encoding->numVars, encoding->variables);
 112         //Add unary constraint
 113         for(uint i=1;i<encoding->numVars;i++) {
 114                 addConstraintCNF(This->cnf, constraintOR2(This->cnf, encoding->variables[i-1], constraintNegate(encoding->variables[i])));
 115         }
 116 }
 117
 118 void generateElementEncoding(SATEncoder* This, Element * element) {
 119         ElementEncoding* encoding = getElementEncoding(element);
 120         ASSERT(encoding->type!=ELEM_UNASSIGNED);
 121         if(encoding->variables!=NULL)
 122                 return;
 123         switch(encoding->type) {
 124         case ONEHOT:
 125                 generateOneHotEncodingVars(This, encoding);
 126                 return;
 127         case BINARYINDEX:
 128                 generateBinaryIndexEncodingVars(This, encoding);
 129                 return;
 130         case UNARY:
 131                 generateUnaryEncodingVars(This, encoding);
 132                 return;
 133         case ONEHOTBINARY:
 134                 return;
 135         case BINARYVAL:
 136                 generateBinaryValueEncodingVars(This, encoding);
 137                 return;
 138         default:
 139                 ASSERT(0);
 140         }
 141 }
 142