Remove the obsolete OverwriteMode optimization.

src/ast.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast.h"
 
 #include <cmath>  // For isfinite.
 #include "src/builtins.h"
 #include "src/code-stubs.h"
 #include "src/contexts.h"
@@ skipping 438 matching lines @@
 void BinaryOperation::RecordToBooleanTypeFeedback(TypeFeedbackOracle* oracle) {
   // TODO(olivf) If this Operation is used in a test context, then the right
   // hand side has a ToBoolean stub and we want to collect the type information.
   // However the GraphBuilder expects it to be on the instruction corresponding
   // to the TestContext, therefore we have to store it here and not on the
   // right hand operand.
   set_to_boolean_types(oracle->ToBooleanTypes(right()->test_id()));
 }
 
 
-bool BinaryOperation::ResultOverwriteAllowed() const {
-  switch (op()) {
-    case Token::COMMA:
-    case Token::OR:
-    case Token::AND:
-      return false;
-    case Token::BIT_OR:
-    case Token::BIT_XOR:
-    case Token::BIT_AND:
-    case Token::SHL:
-    case Token::SAR:
-    case Token::SHR:
-    case Token::ADD:
-    case Token::SUB:
-    case Token::MUL:
-    case Token::DIV:
-    case Token::MOD:
-      return true;
-    default:
-      UNREACHABLE();
-  }
-  return false;
-}
-
-
 static bool IsTypeof(Expression* expr) {
   UnaryOperation* maybe_unary = expr->AsUnaryOperation();
   return maybe_unary != NULL && maybe_unary->op() == Token::TYPEOF;
 }
 
 
 // Check for the pattern: typeof <expression> equals <string literal>.
 static bool MatchLiteralCompareTypeof(Expression* left,
                                       Token::Value op,
                                       Expression* right,
@@ skipping 555 matching lines @@
 // static
 bool Literal::Match(void* literal1, void* literal2) {
   const AstValue* x = static_cast<Literal*>(literal1)->raw_value();
   const AstValue* y = static_cast<Literal*>(literal2)->raw_value();
   return (x->IsString() && y->IsString() && *x->AsString() == *y->AsString()) ||
          (x->IsNumber() && y->IsNumber() && x->AsNumber() == y->AsNumber());
 }
 
 
 } }  // namespace v8::internal