Avoid redundant weak pointer updates after evacuation.

Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=

Committed: https://crrev.com/4db396b172e2e87d95d211934d9baef528cd3043
Cr-Commit-Position: refs/heads/master@{#34555}

[ulan, 2016-03-07 17:47:01]

Description was changed from

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~3x.

BUG=
==========

to

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=
==========

[ulan, 2016-03-07 17:47:01]

ulan@chromium.org changed reviewers:
+ mlippautz@chromium.org

[ulan, 2016-03-07 17:47:33]

ptal

[Michael Lippautz, 2016-03-07 17:59:45]

lgtm

[Michael Lippautz, 2016-03-07 17:59:45]

lgtm

[ulan, 2016-03-07 18:19:05]

The CQ bit was checked by ulan@chromium.org

[commit-bot: I haz the power, 2016-03-07 18:19:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1772803002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1772803002/1

[commit-bot: I haz the power, 2016-03-07 18:44:19]

Description was changed from

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=
==========

to

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=
==========

[commit-bot: I haz the power, 2016-03-07 18:44:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-07 18:45:16]

Description was changed from

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=
==========

to

==========
Avoid redundant weak pointer updates after evacuation.

Since we record slots for weak list fields, there is no need to iterate over
them after evacuation. We just need to update the roots for which we didn't
record slots.

This speeds up the evacuate_update_pointers_weak phase by ~2.5x.

BUG=

Committed: https://crrev.com/4db396b172e2e87d95d211934d9baef528cd3043
Cr-Commit-Position: refs/heads/master@{#34555}
==========

[commit-bot: I haz the power, 2016-03-07 18:45:17]

Patchset 1 (id:??) landed as
https://crrev.com/4db396b172e2e87d95d211934d9baef528cd3043
Cr-Commit-Position: refs/heads/master@{#34555}