Nuke CompareToNull AST node.

src/ast.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 362 matching lines @@
   if (left_unary != NULL && left_unary->op() == Token::VOID &&
       left_unary->expression()->AsLiteral() != NULL) {
     *expr = right_;
     return true;
   }
 
   return false;
 }
 
 
+bool CompareOperation::IsLiteralCompareNull(Expression** expr) {
+  if (op_ != Token::EQ && op_ != Token::EQ_STRICT) return false;
+
+  // Check for the pattern: <expression> equals null.
+  Literal* right_literal = right_->AsLiteral();
+  if (right_literal != NULL && right_literal->handle()->IsNull()) {
+    *expr = left_;
+    return true;
+  }
+
+  // Check for the pattern: null equals <expression>.
+  Literal* left_literal = left_->AsLiteral();
+  if (left_literal != NULL && left_literal->handle()->IsNull()) {
+    *expr = right_;
+    return true;
+  }
+
+  return false;
+}
+
+
 // ----------------------------------------------------------------------------
 // Inlining support
 
 bool Declaration::IsInlineable() const {
   return proxy()->var()->IsStackAllocated() && fun() == NULL;
 }
 
 
 bool TargetCollector::IsInlineable() const {
   UNREACHABLE();
@@ skipping 198 matching lines @@
 bool BinaryOperation::IsInlineable() const {
   return left()->IsInlineable() && right()->IsInlineable();
 }
 
 
 bool CompareOperation::IsInlineable() const {
   return left()->IsInlineable() && right()->IsInlineable();
 }
 
 
-bool CompareToNull::IsInlineable() const {
-  return expression()->IsInlineable();
-}
-
-
 bool CountOperation::IsInlineable() const {
   return expression()->IsInlineable();
 }
 
 
 // ----------------------------------------------------------------------------
 // Recording of type feedback
 
 void Property::RecordTypeFeedback(TypeFeedbackOracle* oracle) {
   // Record type feedback from the oracle in the AST.
@@ skipping 553 matching lines @@
                        int pos)
     : label_(label),
       statements_(statements),
       position_(pos),
       compare_type_(NONE),
       compare_id_(AstNode::GetNextId(isolate)),
       entry_id_(AstNode::GetNextId(isolate)) {
 }
 
 } }  // namespace v8::internal