[turbofan] General consolidation of element access.

[turbofan] General consolidation of element access.

Avoid TransitionElementsKind when storing to objects which only differ
in holeyness of their elements kind. Instead go for polymorphic
CheckMaps, which can often by optimized and avoid the mutation of the
array map.

This generalizes the approach https://codereview.chromium.org/2836943003
which covered only element loads.

R=yangguo@chromium.org
BUG=v8:5267
Review-Url: https://codereview.chromium.org/2836913004
Cr-Commit-Position: refs/heads/master@{#44828}
Committed: https://chromium.googlesource.com/v8/v8/+/ed573cee5c1d1e42158829dc0b92fb697234e121

[Benedikt Meurer, 2017-04-25 04:25:52]

The CQ bit was checked by bmeurer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-25 04:26:02]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-25 04:49:21]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-25 04:49:22]

Dry run: This issue passed the CQ dry run.

[Yang, 2017-04-25 04:54:07]

On 2017/04/25 04:25:50, Benedikt Meurer wrote:

lgtm.

[Benedikt Meurer, 2017-04-25 04:55:52]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-04-25 04:56:02]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-25 04:58:03]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1493096152060030, "parent_rev":
"619ff8c540eb0d3b0a0504d80f850c248d6b4ca9", "commit_rev":
"ed573cee5c1d1e42158829dc0b92fb697234e121"}

[commit-bot: I haz the power, 2017-04-25 04:58:09]

Description was changed from

==========
[turbofan] General consolidation of element access.

Avoid TransitionElementsKind when storing to objects which only differ
in holeyness of their elements kind. Instead go for polymorphic
CheckMaps, which can often by optimized and avoid the mutation of the
array map.

This generalizes the approach https://codereview.chromium.org/2836943003
which covered only element loads.

R=yangguo@chromium.org
BUG=v8:5267
==========

to

==========
[turbofan] General consolidation of element access.

Avoid TransitionElementsKind when storing to objects which only differ
in holeyness of their elements kind. Instead go for polymorphic
CheckMaps, which can often by optimized and avoid the mutation of the
array map.

This generalizes the approach https://codereview.chromium.org/2836943003
which covered only element loads.

R=yangguo@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2836913004
Cr-Commit-Position: refs/heads/master@{#44828}
Committed:
https://chromium.googlesource.com/v8/v8/+/ed573cee5c1d1e42158829dc0b92fb69723...
==========

[commit-bot: I haz the power, 2017-04-25 04:58:10]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/ed573cee5c1d1e42158829dc0b92fb69723...

[Benedikt Meurer, 2017-04-28 05:04:53]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2852623002/ by bmeurer@chromium.org.

The reason for reverting is: Breaks load:tools:drive story.