Switch elements access to use IfBuilder instead of CheckBuilder.

src/hydrogen.cc

 // Copyright 2012 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 852 matching lines @@
   did_else_ = true;
 }
 
 
 void HGraphBuilder::IfBuilder::Deopt() {
   ASSERT(!(did_then_ ^ did_else_));
   HBasicBlock* block = builder_->current_block();
   block->FinishExitWithDeoptimization(HDeoptimize::kUseAll);
   if (did_else_) {
     first_false_block_ = NULL;
-    did_else_ = false;
   } else {
     first_true_block_ = NULL;
   }
 }
 
 
 void HGraphBuilder::IfBuilder::End() {
   if (!captured_) {
     ASSERT(did_then_);
     if (!did_else_) {
       last_true_block_ = builder_->current_block();
     }
     if (first_true_block_ == NULL) {
-      // Deopt on true. Nothing to do, just continue the else block.
+      // Deopt on true. Nothing to do, just continue the false block.
     } else if (first_false_block_ == NULL) {
+      // Deopt on false. Nothing to do except switching to the true block.
       builder_->set_current_block(last_true_block_);
     } else {
       HEnvironment* merge_env = last_true_block_->last_environment()->Copy();
       merge_block_ = builder_->CreateBasicBlock(merge_env);
       ASSERT(!finished_);
       if (!did_else_) Else();
       ASSERT(!last_true_block_->IsFinished());
       HBasicBlock* last_false_block = builder_->current_block();
       ASSERT(!last_false_block->IsFinished());
       last_true_block_->GotoNoSimulate(merge_block_);
@@ skipping 409 matching lines @@
   HValue* checked_key = NULL;
   if (IsExternalArrayElementsKind(elements_kind)) {
     if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
       NoObservableSideEffectsScope no_effects(this);
       HLoadExternalArrayPointer* external_elements =
           new(zone) HLoadExternalArrayPointer(elements);
       AddInstruction(external_elements);
       IfBuilder length_checker(this);
       length_checker.IfCompare(key, length, Token::LT);
       length_checker.Then();
-      CheckBuilder negative_checker(this);
-      HValue* bounds_check = negative_checker.CheckIntegerCompare(
+      IfBuilder negative_checker(this);
+      HValue* bounds_check = negative_checker.IfCompare(
           key, graph()->GetConstant0(), Token::GTE);
-      negative_checker.End();
+      negative_checker.Then();
       HInstruction* result = BuildExternalArrayElementAccess(
           external_elements, key, val, bounds_check,
           elements_kind, is_store);
       AddInstruction(result);
+      negative_checker.Else();
+      negative_checker.Deopt();
+      negative_checker.End();
       length_checker.End();
       return result;
     } else {
       ASSERT(store_mode == STANDARD_STORE);
       checked_key = AddBoundsCheck(
           key, length, ALLOW_SMI_KEY, checked_index_representation);
       HLoadExternalArrayPointer* external_elements =
           new(zone) HLoadExternalArrayPointer(elements);
       AddInstruction(external_elements);
       return AddInstruction(BuildExternalArrayElementAccess(
@@ skipping 10534 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal