[x64] Improve key value sign-extension of dehoisted LoadKeyed/StoreKeyed

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index a58208c816f4f0471be89a44f6e6374b2bc0acdc..ca0dc3b0a85dbc115c319dc38c8d5dc1f588a5aa 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -266,6 +266,10 @@ class LInstruction : public ZoneObject {
 
   virtual bool HasInterestingComment(LCodeGen* gen) const { return true; }
 
+  virtual bool MustSignExtendResult(LPlatformChunk* chunk) const {
+    return false;
+  }
+
 #ifdef DEBUG
   void VerifyCall();
 #endif
@@ -301,6 +305,9 @@ class LTemplateResultInstruction : public LInstruction {
   void set_result(LOperand* operand) { results_[0] = operand; }
   LOperand* result() const { return results_[0]; }
 
+  virtual bool MustSignExtendResult(
+      LPlatformChunk* chunk) const V8_FINAL V8_OVERRIDE;
+
  protected:
   EmbeddedContainer<LOperand*, R> results_;
 };
@@ -2503,10 +2510,15 @@ class LChunkBuilder;
 class LPlatformChunk V8_FINAL : public LChunk {
  public:
   LPlatformChunk(CompilationInfo* info, HGraph* graph)
-      : LChunk(info, graph) { }
+      : LChunk(info, graph),
+        key_values_(graph->GetMaximumValueID(), graph->zone()) { }
 
   int GetNextSpillIndex(RegisterKind kind);
   LOperand* GetNextSpillSlot(RegisterKind kind);
+  BitVector* GetKeyValues() { return &key_values_; }
+
+ private:
+  BitVector key_values_;

[danno, 2014/03/18 08:20:20]

This variable, the accesses for it and naming based on it should be something
more like "dehoisted_key_ids_"

[Weiliang, 2014/03/19 08:55:31]

Done.

 };