[webkit-reviews] review requested: [Bug 22480] We should cache get by id chain accesses polymorphically. : [Attachment 25475] The patch

[bugzilla-daemon at webkit.org]

Gavin Barraclough <barraclough at apple.com> has asked  for review:
Bug 22480: We should cache get by id chain accesses polymorphically.
https://bugs.webkit.org/show_bug.cgi?id=22480

Attachment 25475: The patch
https://bugs.webkit.org/attachment.cgi?id=25475&action=review

------- Additional Comments from Gavin Barraclough <barraclough at apple.com>
	Polymorpic caching for get by id chain.  Similar to the polymorphic
caching already implemented
	for self and proto accesses (implemented by allowing multiple
trampolines to be JIT genertaed,
	and linked together) - the get by id chain caching is implemented as a
genericization of the
	proto list caching, allowing cached access lists to contain a mix of
proto and proto chain
	accesses (since in JS style inheritance hierarchies you may commonly
see a mix of properties
	being overridden on the direct prototype, or higher up its prototype
chain).

	In order to allow this patch to compile there is a fix to appease gcc
4.2 compiler issues
	(removing the jumps between fall-through cases in privateExecute).
	
	This patch also removes redundant immediate checking from the reptach
code, and fixes a related
	memory leak (failure to deallocate trampolines). 

	~2% progression on v8 tests (bulk on the win on deltablue)