Changeset 50254 in webkit for trunk/JavaScriptCore/bytecode/Opcode.h

Timestamp:

Oct 28, 2009, 6:25:02 PM (16 years ago)

Author:

[email protected]

Message:

Improve for..in enumeration performance
​https://bugs.webkit.org/show_bug.cgi?id=30887

Reviewed by Geoff Garen.

Improve indexing of an object with a for..in iterator by
identifying cases where get_by_val is being used with a iterator
as the subscript and replace it with a new get_by_pname
bytecode. get_by_pname then optimizes lookups that directly access
the base object.

File:

• trunk/JavaScriptCore/bytecode/Opcode.h (modified) (1 diff)

trunk/JavaScriptCore/bytecode/Opcode.h

@@ -114 +114 @@
         macro(op_del_by_id, 4) \
         macro(op_get_by_val, 4) \
+        macro(op_get_by_pname, 7) \
         macro(op_put_by_val, 4) \
         macro(op_del_by_val, 4) \