Add MEGAMORPHIC state support for KeyedLoadIC

Add MEGAMORPHIC state support for KeyedLoadIC

BUG=

Committed: https://crrev.com/491eb81780873aafd4d7f6638d20f26839383c68
Cr-Commit-Position: refs/heads/master@{#26345}

[Jakob Kummerow, 2015-01-28 16:32:40]

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

[Jakob Kummerow, 2015-01-28 16:32:41]

I think the first patch set makes more sense. In many of the bailout cases that
jump to "slow", we can't use handlers anyway. The stub cache should only be
polled for sane receivers and keys that are unique names.

This also ties in nicely with the next step we discussed, which is to use the
stub cache to handle the "check_name" label; GenerateKeyNameCheck and
GenerateKeyedLoadReceiverCheck would still happen and after that the stub cache
can be probed (instead of the KLC).

[dcarney, 2015-01-29 10:21:07]

Patchset #2 (id:20001) has been deleted

[Jakob Kummerow, 2015-01-29 15:58:56]

Looks fine. Comments below are for patch set 4; will look at platform ports now.

https://codereview.chromium.org/878263002/diff/80001/src/ic/ic.cc
File src/ic/ic.cc (right):

https://codereview.chromium.org/878263002/diff/80001/src/ic/ic.cc#newcode611
src/ic/ic.cc:611: // TODO(dcarney): what do to here?
Put in a TODO comment into the hydrogen-generated stub that explains that it
needs to be updated not to use the KeyedLookupCache any more. And I'd suggest to
also add an UNREACHABLE right next to the comment to make sure it isn't
overlooked when someone tries to turn on the flag.

Medium term, the generated stub should be beefed up to the point where it can
replace the handwritten one, but that's not at the top of our to-do list
currently.

https://codereview.chromium.org/878263002/diff/80001/src/ic/ic.cc#newcode975
src/ic/ic.cc:975: case GENERIC:
nit: just combine it with the DEFAULT case.

https://codereview.chromium.org/878263002/diff/80001/src/ic/ic.cc#newcode1440
src/ic/ic.cc:1440: ConfigureVectorState(GENERIC);
In a follow-up CL, please port the renaming changes to vector based ICs. That
should be a simple renaming, and it should not hurt to postpone it for now.

[Jakob Kummerow, 2015-01-30 08:49:11]

LGTM

[dcarney, 2015-01-30 08:49:25]

The CQ bit was checked by dcarney@chromium.org

[commit-bot: I haz the power, 2015-01-30 08:50:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/878263002/170001

[commit-bot: I haz the power, 2015-01-30 09:17:09]

Committed patchset #9 (id:170001)

[commit-bot: I haz the power, 2015-01-30 09:17:27]

Patchset 9 (id:??) landed as
https://crrev.com/491eb81780873aafd4d7f6638d20f26839383c68
Cr-Commit-Position: refs/heads/master@{#26345}