Esempio n. 1
0
 @Override
 public void visit(BinaryExpr expr) {
   switch (expr.getOperation()) {
     case AND:
     case OR:
       resultExpr = expr;
       return;
     default:
       break;
   }
   expr.getSecondOperand().acceptVisitor(this);
   Expr b = resultExpr;
   if (b instanceof ConstantExpr && expr.getOperation() == BinaryOperation.SUBTRACT) {
     if (tryMakePositive((ConstantExpr) b)) {
       expr.setOperation(BinaryOperation.ADD);
     }
   }
   expr.getFirstOperand().acceptVisitor(this);
   Expr a = resultExpr;
   Expr p = a;
   Expr q = b;
   boolean invert = false;
   if (isZero(p)) {
     Expr tmp = p;
     p = q;
     q = tmp;
     invert = true;
   }
   if (isComparison(p) && isZero(q)) {
     switch (expr.getOperation()) {
       case EQUALS:
       case NOT_EQUALS:
       case LESS:
       case LESS_OR_EQUALS:
       case GREATER:
       case GREATER_OR_EQUALS:
         {
           BinaryExpr comparison = (BinaryExpr) p;
           Expr result =
               BinaryExpr.binary(
                   expr.getOperation(),
                   comparison.getFirstOperand(),
                   comparison.getSecondOperand());
           result.setLocation(comparison.getLocation());
           if (invert) {
             result = ExprOptimizer.invert(result);
           }
           resultExpr = result;
           return;
         }
       default:
         break;
     }
   }
   expr.setFirstOperand(a);
   expr.setSecondOperand(b);
   resultExpr = expr;
 }
Esempio n. 2
0
 @Override
 public void visit(WhileStatement statement) {
   if (statement.getBody().size() == 1 && statement.getBody().get(0) instanceof WhileStatement) {
     WhileStatement innerLoop = (WhileStatement) statement.getBody().get(0);
     BreakToContinueReplacer replacer = new BreakToContinueReplacer(innerLoop, statement);
     replacer.visitSequence(innerLoop.getBody());
     statement.getBody().clear();
     statement.getBody().addAll(innerLoop.getBody());
   }
   List<Statement> statements = processSequence(statement.getBody());
   for (int i = 0; i < statements.size(); ++i) {
     if (statements.get(i) instanceof ContinueStatement) {
       ContinueStatement continueStmt = (ContinueStatement) statements.get(i);
       if (continueStmt.getTarget() == statement) {
         statements.subList(i, statements.size()).clear();
         break;
       }
     }
   }
   statement.getBody().clear();
   statement.getBody().addAll(statements);
   if (statement.getCondition() != null) {
     List<Statement> sequenceBackup = resultSequence;
     resultSequence = new ArrayList<>();
     statement.getCondition().acceptVisitor(this);
     statement.setCondition(resultExpr);
     resultSequence = sequenceBackup;
   }
   while (true) {
     if (!statement.getBody().isEmpty()
         && statement.getBody().get(0) instanceof ConditionalStatement) {
       ConditionalStatement cond = (ConditionalStatement) statement.getBody().get(0);
       if (cond.getConsequent().size() == 1
           && cond.getConsequent().get(0) instanceof BreakStatement) {
         BreakStatement breakStmt = (BreakStatement) cond.getConsequent().get(0);
         if (breakStmt.getTarget() == statement) {
           statement.getBody().remove(0);
           if (statement.getCondition() != null) {
             Expr newCondition =
                 Expr.binary(
                     BinaryOperation.AND,
                     statement.getCondition(),
                     ExprOptimizer.invert(cond.getCondition()));
             newCondition.setLocation(statement.getCondition().getLocation());
             statement.setCondition(newCondition);
           } else {
             statement.setCondition(ExprOptimizer.invert(cond.getCondition()));
           }
           continue;
         }
       }
     }
     break;
   }
   resultStmt = statement;
 }
Esempio n. 3
0
 private Expr compare(BinaryOperation op, Variable value) {
   Expr expr = Expr.binary(op, Expr.var(value.getIndex()), Expr.constant(0));
   expr.setLocation(currentLocation);
   return expr;
 }
Esempio n. 4
0
 private Expr withLocation(Expr expr) {
   expr.setLocation(currentLocation);
   return expr;
 }