X87: Avoid creating weak cells for literal arrays that are empty of literals.

X87: Avoid creating weak cells for literal arrays that are empty of literals.

  port 3cfcc7e111a32f231a483b8feda19ef2d8c45253 (r36786)

  original commit message:
  It may be that we have a feedback vector, but no literals. In this case
  we can store into the OptimizedCodeMap directly instead of using a WeakCell,
  because all data in the feedback vector is already held weakly.

  The use of a WeakCell in the OptimizedCodeMap is only required when
  there are literals which may hold maps strongly.

  This is to address a performance regression caused by the creation of
  a large number of WeakCells.

BUG=

Committed: https://crrev.com/eef939b4aaf0de0eae2382ae3015e660f3b19c27
Cr-Commit-Position: refs/heads/master@{#37123}

[zhengxing.li, 2016-06-21 02:06:46]

zhengxing.li@intel.com changed reviewers:
+ chunyang.dai@intel.com, mvstanton@chromium.org, weiliang.lin@intel.com

[zhengxing.li, 2016-06-21 02:06:46]

PTAL, thanks!

[Weiliang, 2016-06-21 02:55:03]

lgtm

[zhengxing.li, 2016-06-21 05:18:59]

The CQ bit was checked by zhengxing.li@intel.com

[commit-bot: I haz the power, 2016-06-21 05:19:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2081663004/1

[commit-bot: I haz the power, 2016-06-21 05:40:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-21 05:42:18]

Description was changed from

==========
X87: Avoid creating weak cells for literal arrays that are empty of literals.

  port 3cfcc7e111a32f231a483b8feda19ef2d8c45253 (r36786)

  original commit message:
  It may be that we have a feedback vector, but no literals. In this case
  we can store into the OptimizedCodeMap directly instead of using a WeakCell,
  because all data in the feedback vector is already held weakly.

  The use of a WeakCell in the OptimizedCodeMap is only required when
  there are literals which may hold maps strongly.

  This is to address a performance regression caused by the creation of
  a large number of WeakCells.

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

to

==========
X87: Avoid creating weak cells for literal arrays that are empty of literals.

  port 3cfcc7e111a32f231a483b8feda19ef2d8c45253 (r36786)

  original commit message:
  It may be that we have a feedback vector, but no literals. In this case
  we can store into the OptimizedCodeMap directly instead of using a WeakCell,
  because all data in the feedback vector is already held weakly.

  The use of a WeakCell in the OptimizedCodeMap is only required when
  there are literals which may hold maps strongly.

  This is to address a performance regression caused by the creation of
  a large number of WeakCells.

BUG=

Committed: https://crrev.com/eef939b4aaf0de0eae2382ae3015e660f3b19c27
Cr-Commit-Position: refs/heads/master@{#37123}
==========

[commit-bot: I haz the power, 2016-06-21 05:42:19]

Patchset 1 (id:??) landed as
https://crrev.com/eef939b4aaf0de0eae2382ae3015e660f3b19c27
Cr-Commit-Position: refs/heads/master@{#37123}