Generate less code in v8::internal::Counters constructor

Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 0.1%) of the Chrome APK size of for ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
Review-Url: https://codereview.chromium.org/2759033002
Cr-Commit-Position: refs/heads/master@{#43996}
Committed: https://chromium.googlesource.com/v8/v8/+/53562fd9fbd4a268bd196c93ce3955006097974a

[jbroman, 2017-03-19 05:47:54]

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

[commit-bot: I haz the power, 2017-03-19 05:47:58]

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

[jbroman, 2017-03-19 05:55:26]

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

[commit-bot: I haz the power, 2017-03-19 05:55:28]

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

[jbroman, 2017-03-19 06:12:34]

Description was changed from

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 1%) of the Chrome APK size of for ARM/Android.
==========

to

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 1%) of the Chrome APK size of for ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

[commit-bot: I haz the power, 2017-03-19 06:21:53]

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

[commit-bot: I haz the power, 2017-03-19 06:21:54]

Dry run: This issue passed the CQ dry run.

[jbroman, 2017-03-20 15:06:05]

jbroman@chromium.org changed reviewers:
+ cbruni@chromium.org, fmeawad@chromium.org

[jbroman, 2017-03-20 15:06:06]

WDYT? I'm not eager to make this code slightly messier, but this constructor is
surprisingly large at the moment.

[fmeawad, 2017-03-20 15:13:31]

fmeawad@chromium.org changed reviewers:
+ lpy@chromium.org

[Camillo Bruni, 2017-03-20 17:04:08]

cbruni@chromium.org changed reviewers:
+ ishell@chromium.org

[Camillo Bruni, 2017-03-20 17:04:08]

The runtime call stats changes look definitely good.
Not so sure about the other timers ;) though it's silly to waste so much space
there.

[Igor Sheludko, 2017-03-21 17:39:43]

lgtm

[jbroman, 2017-03-21 18:23:29]

Description was changed from

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 1%) of the Chrome APK size of for ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

to

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately .1%) of the Chrome APK size of for ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

[jbroman, 2017-03-21 18:23:34]

Description was changed from

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately .1%) of the Chrome APK size of for ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

to

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 0.1%) of the Chrome APK size of for
ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

[jbroman, 2017-03-21 19:03:50]

The CQ bit was checked by jbroman@chromium.org

[commit-bot: I haz the power, 2017-03-21 19:03:57]

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

[lpy, 2017-03-21 19:08:56]

LGTM

[commit-bot: I haz the power, 2017-03-21 19:31:16]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1490123030646670,
"parent_rev": "3d3dafee71503ad6efe59893075524d617125422", "commit_rev":
"53562fd9fbd4a268bd196c93ce3955006097974a"}

[commit-bot: I haz the power, 2017-03-21 19:31:24]

Description was changed from

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 0.1%) of the Chrome APK size of for
ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119
==========

to

==========
Generate less code in v8::internal::Counters constructor

This saves 72 KiB (approximately 0.1%) of the Chrome APK size of for
ARM/Android.

In Counters, each similar group of counters generates a compact data structure,
which a loop then iterates over, rather than having the full loop unrolled
(though the compiler will automatically unroll small ones).

In RuntimeCallStats, the compiler was not being clever enough to avoid
initializing count_ and time_ to zero individually, even after the
initialization
of names was moved into a loop. As a result, RuntimeCallCounter was modified
to have a non-initializing constructor for exclusive use by RuntimeCallStats,
which explicitly initializes the counters in a loop. Since v8::base::TimeDelta
does not support an uninitialized state, time_ was changed to be stored as
int64_t microseconds internally, which generates the same code (it's the same
representation as TimeDelta).

BUG=v8:6119

Review-Url: https://codereview.chromium.org/2759033002
Cr-Commit-Position: refs/heads/master@{#43996}
Committed:
https://chromium.googlesource.com/v8/v8/+/53562fd9fbd4a268bd196c93ce395500609...
==========

[commit-bot: I haz the power, 2017-03-21 19:31:25]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/53562fd9fbd4a268bd196c93ce395500609...