Implement xorshift128+ for Math.random.

Implement xorshift128+ for Math.random.

BUG=v8:4566
LOG=N

Committed: https://crrev.com/2755c5a1b1cf7fc4c5c614378e5231636e6dcff5
Cr-Commit-Position: refs/heads/master@{#32200}

Committed: https://crrev.com/085fed0fb5c3b0136827b5d7c190b4bd1c23a23e
Cr-Commit-Position: refs/heads/master@{#32206}

[Yang, 2015-11-23 13:38:35]

yangguo@chromium.org changed reviewers:
+ bmeurer@chromium.org, jkummerow@chromium.org

[Yang, 2015-11-23 13:38:36]

Please take a look. Xorshift128+ is a standard algorithm, and I've verified
locally that it passes TestU01 with flying colors.

[Benedikt Meurer, 2015-11-23 13:39:32]

Can we import TestU01 so we don't regress?

[Yang, 2015-11-23 14:02:44]

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

[commit-bot: I haz the power, 2015-11-23 14:02:47]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1464303002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1464303002/60001

[commit-bot: I haz the power, 2015-11-23 14:16:17]

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

[commit-bot: I haz the power, 2015-11-23 14:16:17]

Dry run: Try jobs failed on following builders:
  v8_win64_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win64_rel/builds/11059)
  v8_win_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_rel/builds/12100)

[Jakob Kummerow, 2015-11-23 14:34:08]

LGTM with nits.

https://codereview.chromium.org/1464303002/diff/40001/src/js/math.js
File src/js/math.js (right):

https://codereview.chromium.org/1464303002/diff/40001/src/js/math.js#newcode14
src/js/math.js:14: define kRandomNumberStart = 2;
nit: maybe add a comment here that indices 0 and 1 are used to store the RNG's
state?

https://codereview.chromium.org/1464303002/diff/40001/src/runtime/runtime-mat...
File src/runtime/runtime-maths.cc (right):

https://codereview.chromium.org/1464303002/diff/40001/src/runtime/runtime-mat...
src/runtime/runtime-maths.cc:262: static const int kByteLength =
kRandomBatchSize * sizeof(double);
"sizeof(double)" used to be a linter violation. You can use kDoubleSize instead.
If no linter complains, then fine, I won't complain either :-)

[Yang, 2015-11-24 09:20:16]

Description was changed from

==========
Implement xorshift128+ for Math.random.
==========

to

==========
Implement xorshift128+ for Math.random.

BUG=v8:4566
LOG=N
==========

[Jakob Kummerow, 2015-11-24 09:24:56]

patch set 6 LGTM

[Yang, 2015-11-24 10:15:52]

The CQ bit was checked by yangguo@chromium.org

[commit-bot: I haz the power, 2015-11-24 10:16:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1464303002/100001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1464303002/100001

[commit-bot: I haz the power, 2015-11-24 10:59:03]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2015-11-24 10:59:38]

Patchset 6 (id:??) landed as
https://crrev.com/2755c5a1b1cf7fc4c5c614378e5231636e6dcff5
Cr-Commit-Position: refs/heads/master@{#32200}

[Yang, 2015-11-24 11:32:17]

A revert of this CL (patchset #6 id:100001) has been created in
https://codereview.chromium.org/1475493003/ by yangguo@chromium.org.

The reason for reverting is: Test failure:
http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20gc%20stress/b....

[Yang, 2015-11-24 12:12:07]

Description was changed from

==========
Implement xorshift128+ for Math.random.

BUG=v8:4566
LOG=N

Committed: https://crrev.com/2755c5a1b1cf7fc4c5c614378e5231636e6dcff5
Cr-Commit-Position: refs/heads/master@{#32200}
==========

to

==========
Implement xorshift128+ for Math.random.

BUG=v8:4566
LOG=N

Committed: https://crrev.com/2755c5a1b1cf7fc4c5c614378e5231636e6dcff5
Cr-Commit-Position: refs/heads/master@{#32200}
==========

[Yang, 2015-11-24 12:32:38]

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

[commit-bot: I haz the power, 2015-11-24 12:32:49]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1464303002/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1464303002/120001

[commit-bot: I haz the power, 2015-11-24 12:35:01]

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

[commit-bot: I haz the power, 2015-11-24 12:35:02]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/...)

[Yang, 2015-11-24 12:37:44]

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

[commit-bot: I haz the power, 2015-11-24 12:37:49]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1464303002/140001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1464303002/140001

[commit-bot: I haz the power, 2015-11-24 13:13:49]

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

[commit-bot: I haz the power, 2015-11-24 13:13:50]

Dry run: This issue passed the CQ dry run.

[Yang, 2015-11-24 13:16:49]

The CQ bit was checked by yangguo@chromium.org

[Yang, 2015-11-24 13:16:49]

The patchset sent to the CQ was uploaded after l-g-t-m from
jkummerow@chromium.org
Link to the patchset: https://codereview.chromium.org/1464303002/#ps140001
(title: "add missing include")

[commit-bot: I haz the power, 2015-11-24 13:17:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1464303002/140001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1464303002/140001

[commit-bot: I haz the power, 2015-11-24 13:18:15]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2015-11-24 13:18:48]

Patchset 8 (id:??) landed as
https://crrev.com/085fed0fb5c3b0136827b5d7c190b4bd1c23a23e
Cr-Commit-Position: refs/heads/master@{#32206}

[Jakob Kummerow, 2015-11-24 13:20:24]

Ah, yes, patch set 8 LGTM, meant to say so sooner.