[x64] Use xorl to materialize smi zero.

[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}

Committed: https://crrev.com/5382e68691e2d869125735a07a19cf04d7f06ab4
Cr-Commit-Position: refs/heads/master@{#32784}

[Benedikt Meurer, 2015-04-15 04:19:25]

Hey Jaro,

This is a straight forward optimization. Please take a look.

Thanks,
Benedikt

[Jarin, 2015-04-15 05:59:51]

lgtm

[Benedikt Meurer, 2015-04-15 06:10:41]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-04-15 06:10:57]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1085153002/1

[commit-bot: I haz the power, 2015-04-15 06:13:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-15 06:14:03]

Patchset 1 (id:??) landed as
https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}

[Benedikt Meurer, 2015-04-16 08:29:51]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1059543004/ by bmeurer@chromium.org.

The reason for reverting is: Seems to cause performance regressions..

[Benedikt Meurer, 2015-12-11 08:41:53]

Description was changed from

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}
==========

to

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}
==========

[Benedikt Meurer, 2015-12-11 09:36:37]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-12-11 09:36:38]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/1085153002/#ps20001
(title: "REBASE")

[commit-bot: I haz the power, 2015-12-11 09:36:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1085153002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1085153002/20001

[commit-bot: I haz the power, 2015-12-11 09:38:30]

Description was changed from

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}
==========

to

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}
==========

[commit-bot: I haz the power, 2015-12-11 09:38:31]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-12-11 09:39:02]

Description was changed from

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}
==========

to

==========
[x64] Use xorl to materialize smi zero.

Before we always loaded smi zero via a movabs with a 64-bit immediate,
which is pretty expensive compared to the xorl.

R=jarin@chromium.org

Committed: https://crrev.com/f236777bfe6e080ff1ead6baf847cc9b6bb4f9cb
Cr-Commit-Position: refs/heads/master@{#27829}

Committed: https://crrev.com/5382e68691e2d869125735a07a19cf04d7f06ab4
Cr-Commit-Position: refs/heads/master@{#32784}
==========

[commit-bot: I haz the power, 2015-12-11 09:39:03]

Patchset 2 (id:??) landed as
https://crrev.com/5382e68691e2d869125735a07a19cf04d7f06ab4
Cr-Commit-Position: refs/heads/master@{#32784}