Reviewers: William Hesse,
Description:
Emit a load of the elements array only before the first store.
This avoid emitting the load for empty and constant array literals.
Please review this at http://codereview.chromium.org/5697006/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/hydrogen.cc
Index: src/hydrogen.cc
===================================================================
--- src/hydrogen.cc (revision 6029)
+++ src/hydrogen.cc (working copy)
@@ -3023,8 +3023,9 @@
// 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);
// If the subexpression is a literal or a simple materialized literal
it
@@ -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));
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
