[turbofan] Introduce dedicated NumberToBoolean operator.

[turbofan] Introduce dedicated NumberToBoolean operator.

Previously we always lowered JSToBoolean(x:Number) to the subgraph
NumberLessThan(0.0, NumberAbs(x)), which deals with both 0, -0 and
NaNs appropriately. However this doesn't always generate the best,
especially when we can later derive from feedback that x is always
an Integral32 value, where the ideal code would be just a single
comparison to 0 w/o the absolute value computation.

R=mvstanton@chromium.org
BUG=v8:5267, v8:5270
Committed: https://crrev.com/c071a8f0ca096c28a1c6bf7a5d1304f121d027ff
Cr-Commit-Position: refs/heads/master@{#39194}

[Benedikt Meurer, 2016-09-06 06:06:25]

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

[commit-bot: I haz the power, 2016-09-06 06:06:30]

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

[Benedikt Meurer, 2016-09-06 06:07:02]

Hey Michael,

Here's another low hanging fruit that we missed so far.
Please take a look.

Thanks,
Benedikt

[commit-bot: I haz the power, 2016-09-06 06:20:59]

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

[commit-bot: I haz the power, 2016-09-06 06:21:00]

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...)
  v8_linux64_gyp_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_gyp_rel_ng_trigg...)

[Benedikt Meurer, 2016-09-06 06:52:20]

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

[commit-bot: I haz the power, 2016-09-06 06:52:23]

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, 2016-09-06 07:15:22]

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

[commit-bot: I haz the power, 2016-09-06 07:15:23]

Dry run: This issue passed the CQ dry run.

[mvstanton, 2016-09-06 08:14:40]

lgtm

[Benedikt Meurer, 2016-09-06 08:47:52]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-09-06 08:48:04]

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, 2016-09-06 08:54:26]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-06 08:55:01]

Description was changed from

==========
[turbofan] Introduce dedicated NumberToBoolean operator.

Previously we always lowered JSToBoolean(x:Number) to the subgraph
NumberLessThan(0.0, NumberAbs(x)), which deals with both 0, -0 and
NaNs appropriately. However this doesn't always generate the best,
especially when we can later derive from feedback that x is always
an Integral32 value, where the ideal code would be just a single
comparison to 0 w/o the absolute value computation.

R=mvstanton@chromium.org
BUG=v8:5267,v8:5270
==========

to

==========
[turbofan] Introduce dedicated NumberToBoolean operator.

Previously we always lowered JSToBoolean(x:Number) to the subgraph
NumberLessThan(0.0, NumberAbs(x)), which deals with both 0, -0 and
NaNs appropriately. However this doesn't always generate the best,
especially when we can later derive from feedback that x is always
an Integral32 value, where the ideal code would be just a single
comparison to 0 w/o the absolute value computation.

R=mvstanton@chromium.org
BUG=v8:5267,v8:5270

Committed: https://crrev.com/c071a8f0ca096c28a1c6bf7a5d1304f121d027ff
Cr-Commit-Position: refs/heads/master@{#39194}
==========

[commit-bot: I haz the power, 2016-09-06 08:55:01]

Patchset 2 (id:??) landed as
https://crrev.com/c071a8f0ca096c28a1c6bf7a5d1304f121d027ff
Cr-Commit-Position: refs/heads/master@{#39194}