[turbofan] Introduce dedicated CallFrequency class.

[turbofan] Introduce dedicated CallFrequency class.

When we don't know the call count for a given call site (i.e. for
inlined accessors), we put 0 as call frequency so far. But as of
https://codereview.chromium.org/2859433002, this would completely
disable the inlining of those calls, since 0 is interpreted as never
called, which is not what we want. So instead of defaulting to 0,
add a dedicated sentinel, whose value is NaN, which makes the call
site eligible for inlining, but not high priority (as it was before
the CL mentioned above).

BUG=v8:4493, v8:5267
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2856103002
Cr-Commit-Position: refs/heads/master@{#45053}
Committed: https://chromium.googlesource.com/v8/v8/+/23ee74310b2d1aab30e1be3ae1fdba8850357734

[Benedikt Meurer, 2017-05-03 05:58:10]

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

[commit-bot: I haz the power, 2017-05-03 05:58:12]

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, 2017-05-03 06:31:29]

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

[commit-bot: I haz the power, 2017-05-03 06:31:30]

Dry run: This issue passed the CQ dry run.

[Benedikt Meurer, 2017-05-03 07:55:54]

Description was changed from

==========
[turbofan] Introduce dedicated kUnknownCallFrequency sentinel.

When we don't know the call count for a given call site (i.e. for
inlined accessors), we put 0 as call frequency so far. But as of
https://codereview.chromium.org/2859433002, this would completely
disable the inlining of those calls, since 0 is interpreted as never
called, which is not what we want. So instead of defaulting to 0,
add a dedicated sentinel, whose value is NaN, which makes the call
site eligible for inlining, but not high priority (as it was before
the CL mentioned above).

BUG=v8:4493,v8:5267
R=jarin@chromium.org
==========

to

==========
[turbofan] Introduce dedicated CallFrequency class.

When we don't know the call count for a given call site (i.e. for
inlined accessors), we put 0 as call frequency so far. But as of
https://codereview.chromium.org/2859433002, this would completely
disable the inlining of those calls, since 0 is interpreted as never
called, which is not what we want. So instead of defaulting to 0,
add a dedicated sentinel, whose value is NaN, which makes the call
site eligible for inlining, but not high priority (as it was before
the CL mentioned above).

BUG=v8:4493,v8:5267
R=jarin@chromium.org
==========

[Benedikt Meurer, 2017-05-03 07:56:21]

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

[commit-bot: I haz the power, 2017-05-03 07:56:25]

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, 2017-05-03 08:25:04]

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

[commit-bot: I haz the power, 2017-05-03 08:25:05]

Dry run: This issue passed the CQ dry run.

[Jarin, 2017-05-03 09:51:04]

lgtm

[Benedikt Meurer, 2017-05-03 09:54:48]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-05-03 09:54:55]

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, 2017-05-03 09:57:32]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1493805288781510,
"parent_rev": "76a84bbcc6cad6603431349d3864e06c7d16e390", "commit_rev":
"23ee74310b2d1aab30e1be3ae1fdba8850357734"}

[commit-bot: I haz the power, 2017-05-03 09:57:37]

Description was changed from

==========
[turbofan] Introduce dedicated CallFrequency class.

When we don't know the call count for a given call site (i.e. for
inlined accessors), we put 0 as call frequency so far. But as of
https://codereview.chromium.org/2859433002, this would completely
disable the inlining of those calls, since 0 is interpreted as never
called, which is not what we want. So instead of defaulting to 0,
add a dedicated sentinel, whose value is NaN, which makes the call
site eligible for inlining, but not high priority (as it was before
the CL mentioned above).

BUG=v8:4493,v8:5267
R=jarin@chromium.org
==========

to

==========
[turbofan] Introduce dedicated CallFrequency class.

When we don't know the call count for a given call site (i.e. for
inlined accessors), we put 0 as call frequency so far. But as of
https://codereview.chromium.org/2859433002, this would completely
disable the inlining of those calls, since 0 is interpreted as never
called, which is not what we want. So instead of defaulting to 0,
add a dedicated sentinel, whose value is NaN, which makes the call
site eligible for inlining, but not high priority (as it was before
the CL mentioned above).

BUG=v8:4493,v8:5267
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2856103002
Cr-Commit-Position: refs/heads/master@{#45053}
Committed:
https://chromium.googlesource.com/v8/v8/+/23ee74310b2d1aab30e1be3ae1fdba88503...
==========

[commit-bot: I haz the power, 2017-05-03 09:57:38]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/23ee74310b2d1aab30e1be3ae1fdba88503...