[ignition/turbo] Add liveness analysis for the accumulator

[ignition/turbo] Add liveness analysis for the accumulator

Adds a boolean flag to the liveness analysis which makes it also analyze
the accumulator. This can help prevent the accumulator escaping loops,
as well as decreasing the number of distinct state values nodes in the
graph.

The flag is a kind of ugly way to hack this in, however it is probably
the simplest to add, and (more importantly) to remove once the AST graph
builder is gone.

I measure a 2.6% improvement on Mandreel on my x64 machine, and a ~2%
improvement on Navier-Stokes. Other improvements are expected.

Committed: https://crrev.com/0c1727ad790463df7f85664613ed4a66e59df429
Cr-Commit-Position: refs/heads/master@{#40359}

[Leszek Swirski, 2016-10-17 10:04:58]

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

[commit-bot: I haz the power, 2016-10-17 10:05:06]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Leszek Swirski, 2016-10-17 10:11:51]

leszeks@chromium.org changed reviewers:
+ jarin@chromium.org

[Leszek Swirski, 2016-10-17 10:11:51]

Hey Jaro, here's a patch for the accumulator liveness analysis. Let me know what
you think.

[commit-bot: I haz the power, 2016-10-17 10:14:13]

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

[commit-bot: I haz the power, 2016-10-17 10:14:14]

Dry run: Try jobs failed on following builders:
  v8_linux64_gyp_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng/build...)

[Leszek Swirski, 2016-10-17 10:28:57]

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

[commit-bot: I haz the power, 2016-10-17 10:29:03]

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, 2016-10-17 10:52:47]

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

[commit-bot: I haz the power, 2016-10-17 10:52:48]

Dry run: This issue passed the CQ dry run.

[Jarin, 2016-10-17 11:26:10]

Very nice. lgtm.

For readability, it might be nice to introduce an enum instead of the bool for
the liveness mode (something like enum LivenessAnalyzerMode { kLocalsOnly,
kLocalsAndAccumulator }), but I'll leave that up to you. Once we nuke
ast-graph-builder, the bool will go away anyway.

[Leszek Swirski, 2016-10-17 11:43:53]

Thanks. There's actually a version I have locally which had exactly this enum
(mine has AST and BYTECODE as the values), but I changed it to a bool to
discourage anyone from extending it any further (e.g.
kParametersAndLocalsAndAccumulator), so I'll keep it as a bool if you don't
object.

[Leszek Swirski, 2016-10-17 11:44:01]

The CQ bit was checked by leszeks@chromium.org

[commit-bot: I haz the power, 2016-10-17 11:44:10]

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, 2016-10-17 11:47:50]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-10-17 11:48:11]

Description was changed from

==========
[ignition/turbo] Add liveness analysis for the accumulator

Adds a boolean flag to the liveness analysis which makes it also analyze
the accumulator. This can help prevent the accumulator escaping loops,
as well as decreasing the number of distinct state values nodes in the
graph.

The flag is a kind of ugly way to hack this in, however it is probably
the simplest to add, and (more importantly) to remove once the AST graph
builder is gone.

I measure a 2.6% improvement on Mandreel on my x64 machine, and a ~2%
improvement on Navier-Stokes. Other improvements are expected.
==========

to

==========
[ignition/turbo] Add liveness analysis for the accumulator

Adds a boolean flag to the liveness analysis which makes it also analyze
the accumulator. This can help prevent the accumulator escaping loops,
as well as decreasing the number of distinct state values nodes in the
graph.

The flag is a kind of ugly way to hack this in, however it is probably
the simplest to add, and (more importantly) to remove once the AST graph
builder is gone.

I measure a 2.6% improvement on Mandreel on my x64 machine, and a ~2%
improvement on Navier-Stokes. Other improvements are expected.

Committed: https://crrev.com/0c1727ad790463df7f85664613ed4a66e59df429
Cr-Commit-Position: refs/heads/master@{#40359}
==========

[commit-bot: I haz the power, 2016-10-17 11:48:13]

Patchset 3 (id:??) landed as
https://crrev.com/0c1727ad790463df7f85664613ed4a66e59df429
Cr-Commit-Position: refs/heads/master@{#40359}