[turbofan] Use unreliable LOAD_IC feedback for Array.prototype.push.

[turbofan] Use unreliable LOAD_IC feedback for Array.prototype.push.

Add the notion of reliable vs. unreliable receiver map information to
the NodeProperties::InferReceiverMaps machinery. The information is
considered reliable here if the maps are known to be valid based on the
effect chain, and unreliable if there was a side-effect in between that
might have changed the receiver map.

Use this unreliable information for Array.prototype.push, guarded by
either stability dependencies or map checks, which might present a
potential deoptimization loop, which is very unlikely, but still needs
fixing in the future. This is important to optimize calls to push even
in cases like this

  array.push(something.func());

where we have a side-effect (the call to something.func) between the
load of array.push and the actual call.

R=jarin@chromium.org
BUG=v8:5267, v8:6241
Review-Url: https://codereview.chromium.org/2812233002
Cr-Commit-Position: refs/heads/master@{#44595}
Committed: https://chromium.googlesource.com/v8/v8/+/1fceaf9f8c971b5ca41b67dc41487278d8259748

[Benedikt Meurer, 2017-04-12 05:33:45]

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

[commit-bot: I haz the power, 2017-04-12 05:33:55]

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, 2017-04-12 06:16:25]

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

[commit-bot: I haz the power, 2017-04-12 06:16:25]

Dry run: This issue passed the CQ dry run.

[Jarin, 2017-04-12 06:31:17]

lgtm

[Benedikt Meurer, 2017-04-12 06:31:28]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-04-12 06:31:36]

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, 2017-04-12 06:33:00]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1491978688513770, "parent_rev":
"a7c4e778466633d838c7f7d538da890853d5ea51", "commit_rev":
"1fceaf9f8c971b5ca41b67dc41487278d8259748"}

[commit-bot: I haz the power, 2017-04-12 06:33:05]

Description was changed from

==========
[turbofan] Use unreliable LOAD_IC feedback for Array.prototype.push.

Add the notion of reliable vs. unreliable receiver map information to
the NodeProperties::InferReceiverMaps machinery. The information is
considered reliable here if the maps are known to be valid based on the
effect chain, and unreliable if there was a side-effect in between that
might have changed the receiver map.

Use this unreliable information for Array.prototype.push, guarded by
either stability dependencies or map checks, which might present a
potential deoptimization loop, which is very unlikely, but still needs
fixing in the future. This is important to optimize calls to push even
in cases like this

  array.push(something.func());

where we have a side-effect (the call to something.func) between the
load of array.push and the actual call.

R=jarin@chromium.org
BUG=v8:5267,v8:6241
==========

to

==========
[turbofan] Use unreliable LOAD_IC feedback for Array.prototype.push.

Add the notion of reliable vs. unreliable receiver map information to
the NodeProperties::InferReceiverMaps machinery. The information is
considered reliable here if the maps are known to be valid based on the
effect chain, and unreliable if there was a side-effect in between that
might have changed the receiver map.

Use this unreliable information for Array.prototype.push, guarded by
either stability dependencies or map checks, which might present a
potential deoptimization loop, which is very unlikely, but still needs
fixing in the future. This is important to optimize calls to push even
in cases like this

  array.push(something.func());

where we have a side-effect (the call to something.func) between the
load of array.push and the actual call.

R=jarin@chromium.org
BUG=v8:5267,v8:6241

Review-Url: https://codereview.chromium.org/2812233002
Cr-Commit-Position: refs/heads/master@{#44595}
Committed:
https://chromium.googlesource.com/v8/v8/+/1fceaf9f8c971b5ca41b67dc41487278d82...
==========

[commit-bot: I haz the power, 2017-04-12 06:33:06]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/1fceaf9f8c971b5ca41b67dc41487278d82...