Add MEGAMORPHIC state support for KeyedStoreIC

Add MEGAMORPHIC state support for KeyedStoreIC

R=mvstanton@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=24500

[Jakob Kummerow, 2014-10-07 10:39:15]

jkummerow@chromium.org changed reviewers:
+ mvstanton@chromium.org

[Jakob Kummerow, 2014-10-07 10:39:16]

Please take a look.

As discussed offline, a planned follow-up is to replace StoreIC::generic_stub()
with StoreIC::slow_stub() (or megamorphic_stub() where it makes sense).

[mvstanton, 2014-10-08 14:04:51]

LGTM, good luck with the !is_target_set() piece :).

https://codereview.chromium.org/584043002/diff/20001/src/ic/ic.cc
File src/ic/ic.cc (right):

https://codereview.chromium.org/584043002/diff/20001/src/ic/ic.cc#newcode905
src/ic/ic.cc:905: if (kind() == Code::KEYED_LOAD_IC) return;
Maybe a comment here? I'm not sure why keyed stores get to update the cache, but
keyed loads don't.

https://codereview.chromium.org/584043002/diff/20001/src/ic/x64/stub-cache-x6...
File src/ic/x64/stub-cache-x64.cc (right):

https://codereview.chromium.org/584043002/diff/20001/src/ic/x64/stub-cache-x6...
src/ic/x64/stub-cache-x64.cc:44: __ cmpp(name, Operand(kScratchRegister, offset,
scale_factor, 0));
+1, simpler :)

[Jakob Kummerow, 2014-10-09 14:31:00]

Committed patchset #4 (id:60001) manually as 24500 (presubmit successful).

[Jakob Kummerow, 2014-10-20 10:39:38]

(just found this unsent draft comment)

https://codereview.chromium.org/584043002/diff/20001/src/ic/ic.cc
File src/ic/ic.cc (right):

https://codereview.chromium.org/584043002/diff/20001/src/ic/ic.cc#newcode905
src/ic/ic.cc:905: if (kind() == Code::KEYED_LOAD_IC) return;
On 2014/10/08 14:04:51, mvstanton wrote:
> Maybe a comment here? I'm not sure why keyed stores get to update the cache,
but
> keyed loads don't.

Because this CL adds megamorphic state for keyed stores. Keyed loads are never
megamorphic. Comment added.