[turbofan] Introduce a dedicated CheckMaps simplified operator.

[turbofan] Introduce a dedicated CheckMaps simplified operator.

So far we always create explicit control flow for map checks during
JSNativeContextSpecialization, or in the monomorphic case we used a
CheckIf combined with a map comparison. In either case we cannot
currently effectively utilize the map check information during load
elimination to optimize (polymorphic) map checks and elements kind
transitions.

With the introduction of CheckMaps, we can now start optimizing map
checks in a more effective fashion. This CL doesn't change anything
in that direction yet, but merely changes the fundamental mechanism.

This also removes the stable map optimization from the Typer, where
it was always a bit odd, and puts it into the typed lowering and
the native context specialization instead.

R=epertoso@chromium.org
BUG=v8:4930, v8:5141
Committed: https://crrev.com/8201579e031aee4118e7a98ac0991418d01fd06a
Cr-Commit-Position: refs/heads/master@{#38166}

[Benedikt Meurer, 2016-07-29 07:34:54]

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

[commit-bot: I haz the power, 2016-07-29 07:35:00]

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, 2016-07-29 07:57:30]

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

[commit-bot: I haz the power, 2016-07-29 07:57:31]

Dry run: This issue passed the CQ dry run.

[epertoso, 2016-07-29 09:34:08]

lgtm

https://codereview.chromium.org/2196653002/diff/1/src/compiler/js-native-cont...
File src/compiler/js-native-context-specialization.cc (right):

https://codereview.chromium.org/2196653002/diff/1/src/compiler/js-native-cont...
src/compiler/js-native-context-specialization.cc:543: // Create single
chokepoint for the control.
nit: do you mean checkpoint?

[Benedikt Meurer, 2016-07-29 09:37:49]

https://codereview.chromium.org/2196653002/diff/1/src/compiler/js-native-cont...
File src/compiler/js-native-context-specialization.cc (right):

https://codereview.chromium.org/2196653002/diff/1/src/compiler/js-native-cont...
src/compiler/js-native-context-specialization.cc:543: // Create single
chokepoint for the control.
Yes.

[Benedikt Meurer, 2016-07-29 09:38:06]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-07-29 09:38:19]

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, 2016-07-29 09:39:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-07-29 09:41:28]

Description was changed from

==========
[turbofan] Introduce a dedicated CheckMaps simplified operator.

So far we always create explicit control flow for map checks during
JSNativeContextSpecialization, or in the monomorphic case we used a
CheckIf combined with a map comparison. In either case we cannot
currently effectively utilize the map check information during load
elimination to optimize (polymorphic) map checks and elements kind
transitions.

With the introduction of CheckMaps, we can now start optimizing map
checks in a more effective fashion. This CL doesn't change anything
in that direction yet, but merely changes the fundamental mechanism.

This also removes the stable map optimization from the Typer, where
it was always a bit odd, and puts it into the typed lowering and
the native context specialization instead.

R=epertoso@chromium.org
BUG=v8:4930,v8:5141
==========

to

==========
[turbofan] Introduce a dedicated CheckMaps simplified operator.

So far we always create explicit control flow for map checks during
JSNativeContextSpecialization, or in the monomorphic case we used a
CheckIf combined with a map comparison. In either case we cannot
currently effectively utilize the map check information during load
elimination to optimize (polymorphic) map checks and elements kind
transitions.

With the introduction of CheckMaps, we can now start optimizing map
checks in a more effective fashion. This CL doesn't change anything
in that direction yet, but merely changes the fundamental mechanism.

This also removes the stable map optimization from the Typer, where
it was always a bit odd, and puts it into the typed lowering and
the native context specialization instead.

R=epertoso@chromium.org
BUG=v8:4930,v8:5141

Committed: https://crrev.com/8201579e031aee4118e7a98ac0991418d01fd06a
Cr-Commit-Position: refs/heads/master@{#38166}
==========

[commit-bot: I haz the power, 2016-07-29 09:41:29]

Patchset 1 (id:??) landed as
https://crrev.com/8201579e031aee4118e7a98ac0991418d01fd06a
Cr-Commit-Position: refs/heads/master@{#38166}