Fix for performance issue 353661 - 23% regression in dromaeo.

Fix for performance issue 353661 - 23% regression in dromaeo.

The issue was that a previous fix to avoid a logic error was not
targeted enough: it allowed non-transitioning stores to fall
into a code path meant to preserve monomorphic state in the
case of a transitioning store.

BUG=353661
LOG=N
R=verwaest@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=20127

[mvstanton, 2014-03-20 11:01:25]

Hi Toon, PTAL, thx!
--Michael

[Toon Verwaest, 2014-03-20 13:04:52]

Doh! :) LGTM

[mvstanton, 2014-03-20 13:38:14]

Committed patchset #1 manually as r20127 (presubmit successful).

[Weiliang, 2014-04-02 08:20:11]

On 2014/03/20 13:38:14, mvstanton wrote:
> Committed patchset #1 manually as r20127 (presubmit successful).

Hi Micheal,
Will V8 back port this patch to 3.24 branch. This CL seems to have big
performance impact on DOM cases. I see that your previous
patch(https://code.google.com/p/v8/source/detail?r=19893) is already in V8
3.24.35.17.It would be better we also back port this patch to fix the
performance issue in V8 3.24 (Chrome M34).

Thanks
-Weiliang