[turbofan] Initial support for transitioning stores.

[turbofan] Initial support for transitioning stores.

Add support for stores that transition to writable data fields,
based on the BeginRegion/FinishRegion mechanism for atomic regions
in the scheduler.

This is early work and still a bit rough around the edges, and similar
to regular stores, we don't support transitioning stores to double
fields yet.

R=jarin@chromium.org
BUG=v8:4470
LOG=n

Committed: https://crrev.com/a0b8650e6555652267698481873beecd263bd463
Cr-Commit-Position: refs/heads/master@{#31645}

[Benedikt Meurer, 2015-10-29 07:33:18]

Description was changed from

==========
[turbofan] Initial support for transitioning stores.

Add support for stores that transition to in-object, writable data fields,
based on the BeginRegion/FinishRegion mechanism for atomic regions in the
scheduler.

This is early work and still a bit rough around the edges, and similar
to regular stores, we don't support transitioning stores to double
fields yet.

R=jarin@chromium.org
BUG=v8:4470
LOG=n
==========

to

==========
[turbofan] Initial support for transitioning stores.

Add support for stores that transition to writable data fields,
based on the BeginRegion/FinishRegion mechanism for atomic regions in the
scheduler.

This is early work and still a bit rough around the edges, and similar
to regular stores, we don't support transitioning stores to double
fields yet.

R=jarin@chromium.org
BUG=v8:4470
LOG=n
==========

[Benedikt Meurer, 2015-10-29 07:33:30]

Description was changed from

==========
[turbofan] Initial support for transitioning stores.

Add support for stores that transition to writable data fields,
based on the BeginRegion/FinishRegion mechanism for atomic regions in the
scheduler.

This is early work and still a bit rough around the edges, and similar
to regular stores, we don't support transitioning stores to double
fields yet.

R=jarin@chromium.org
BUG=v8:4470
LOG=n
==========

to

==========
[turbofan] Initial support for transitioning stores.

Add support for stores that transition to writable data fields,
based on the BeginRegion/FinishRegion mechanism for atomic regions
in the scheduler.

This is early work and still a bit rough around the edges, and similar
to regular stores, we don't support transitioning stores to double
fields yet.

R=jarin@chromium.org
BUG=v8:4470
LOG=n
==========

[Benedikt Meurer, 2015-10-29 07:34:16]

Hey Jaro,

This is the initial version of transitioning stores.
Please take a look.

Thanks,
Benedikt

[Jarin, 2015-10-29 09:02:33]

lgtm.

https://codereview.chromium.org/1406153010/diff/20001/src/compiler/js-native-...
File src/compiler/js-native-context-specialization.cc (right):

https://codereview.chromium.org/1406153010/diff/20001/src/compiler/js-native-...
src/compiler/js-native-context-specialization.cc:492: // Check if the
{receiver_map} has a data transition with the given {name}.
The structure of this code is strange. This whole chunk would seem to belong to
the place where you "break" out of the loop (well, ideally factored out into a
separate method).

[Benedikt Meurer, 2015-10-29 09:03:47]

https://codereview.chromium.org/1406153010/diff/20001/src/compiler/js-native-...
File src/compiler/js-native-context-specialization.cc (right):

https://codereview.chromium.org/1406153010/diff/20001/src/compiler/js-native-...
src/compiler/js-native-context-specialization.cc:492: // Check if the
{receiver_map} has a data transition with the given {name}.
Yes, but currently we have two "break" points. I want to rewrite the method when
I add the NotFound case, which also depends on the "break".

[Benedikt Meurer, 2015-10-29 09:04:11]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-10-29 09:04:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1406153010/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1406153010/20001

[commit-bot: I haz the power, 2015-10-29 09:05:54]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-10-29 09:06:36]

Patchset 2 (id:??) landed as
https://crrev.com/a0b8650e6555652267698481873beecd263bd463
Cr-Commit-Position: refs/heads/master@{#31645}