Revision: 6034
Author: [email protected]
Date: Wed Dec 15 08:12:55 2010
Log: Emit a load of the elements array only before the first store.
This avoid emitting the load for empty and constant array literals.
Review URL: http://codereview.chromium.org/5697006
http://code.google.com/p/v8/source/detail?r=6034
Modified:
/branches/bleeding_edge/src/hydrogen.cc
=======================================
--- /branches/bleeding_edge/src/hydrogen.cc Wed Dec 15 04:32:19 2010
+++ /branches/bleeding_edge/src/hydrogen.cc Wed Dec 15 08:12:55 2010
@@ -3023,7 +3023,8 @@
// The array is expected in the bailout environment during computation
// of the property values and is the value of the entire expression.
PushAndAdd(literal);
- HValue* elements = AddInstruction(new HLoadElements(literal));
+
+ HLoadElements* elements = NULL;
for (int i = 0; i < length; i++) {
Expression* subexpr = subexprs->at(i);
@@ -3034,6 +3035,13 @@
VISIT_FOR_VALUE(subexpr);
HValue* value = Pop();
if (!Smi::IsValid(i)) BAILOUT("Non-smi key in array literal");
+
+ // Load the elements array before the first store.
+ if (elements == NULL) {
+ elements = new HLoadElements(literal);
+ AddInstruction(elements);
+ }
+
HValue* key = AddInstruction(new
HConstant(Handle<Object>(Smi::FromInt(i)),
Representation::Integer32()));
AddInstruction(new HStoreKeyedFastElement(elements, key, value));
--
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