[turbofan] always run value numbering last to patch unpredictable reductions

[turbofan] always run value numbering last to patch unpredictable reductions

This extends https://codereview.chromium.org/2728983002 to all of Turbofan, for the same reasons: The machine reducer is unreliable in signalling changed nodes and value numbering is unpredictable if not always re-run on changed nodes. Putting value numbering last in all graph reducers patches this.

BUG=v8:6036
R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2730753003
Cr-Commit-Position: refs/heads/master@{#43617}
Committed: https://chromium.googlesource.com/v8/v8/+/1338ae97ded61c7d7315d9736d4c442979951bb7

[Tobias Tebbi, 2017-03-03 09:57:54]

It is currently not observable on the bots anymore because Benedikt added
another opcode, but I locally verified that this fixes the remaining
unpredictability issue.

[Michael Starzinger, 2017-03-06 16:40:46]

LGTM.

[Tobias Tebbi, 2017-03-06 16:51:54]

The CQ bit was checked by tebbi@chromium.org

[commit-bot: I haz the power, 2017-03-06 16:51:58]

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, 2017-03-06 17:15:50]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1488819114285170, "parent_rev":
"47276d3db3dab6b4f1dd2ddb8b8088ccc0d0673e", "commit_rev":
"1338ae97ded61c7d7315d9736d4c442979951bb7"}

[commit-bot: I haz the power, 2017-03-06 17:15:57]

Description was changed from

==========
[turbofan] always run value numbering last to patch unpredictable reductions

This extends https://codereview.chromium.org/2728983002 to all of Turbofan, for
the same reasons: The machine reducer is unreliable in signalling changed nodes
and value numbering is unpredictable if not always re-run on changed nodes.
Putting value numbering last in all graph reducers patches this.

BUG=v8:6036
R=mstarzinger@chromium.org
==========

to

==========
[turbofan] always run value numbering last to patch unpredictable reductions

This extends https://codereview.chromium.org/2728983002 to all of Turbofan, for
the same reasons: The machine reducer is unreliable in signalling changed nodes
and value numbering is unpredictable if not always re-run on changed nodes.
Putting value numbering last in all graph reducers patches this.

BUG=v8:6036
R=mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2730753003
Cr-Commit-Position: refs/heads/master@{#43617}
Committed:
https://chromium.googlesource.com/v8/v8/+/1338ae97ded61c7d7315d9736d4c4429799...
==========

[commit-bot: I haz the power, 2017-03-06 17:15:58]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/1338ae97ded61c7d7315d9736d4c4429799...