Some improvements in register usage in lithium compilation of LoadKeyed/StoreKeyed operations.

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 7255c8d340fcf2652c8334007b416ec9094adf1c..4bceb152b577bd564be388eb92a99d764192e5aa 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -1371,6 +1371,14 @@ class LLoadKeyed: public LTemplateInstruction<1, 2, 0> {
 };
 
 
+template <class T>
+inline static bool ArrayOpClobbersKey(T *value) {

[danno, 2012/11/07 22:34:38]

You can move this to the .cc file. It's only used internally.

[mvstanton, 2012/11/09 09:43:13]

Shucks, it is actually used in both lithium-x64.cc and lithium-codegen-x64.cc so
I would rather keep it here. I thought about moving it "deeper" into codegen by
placing it in lithium-codegen-x64.h, but since it operates on Hydrogen
instructions that didn't feel right either.

+  CHECK(value->IsLoadKeyed() || value->IsStoreKeyed());
+  return !value->IsConstant() && (value->key()->representation().IsTagged()
+                                  || value->IsDehoisted());
+}
+
+
 class LLoadKeyedGeneric: public LTemplateInstruction<1, 2, 0> {
  public:
   LLoadKeyedGeneric(LOperand* obj, LOperand* key) {