[x64] Zero/sign-extend loads to 64-bit registers.

[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a 32-bit register, then zero/sign-extend from that register to a 64-bit one. Now we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Committed: https://crrev.com/b79d7b0486779cea1af6ec17b2fe468e6973fd38
Cr-Original-Commit-Position: refs/heads/master@{#38388}
Cr-Commit-Position: refs/heads/master@{#38428}

[epertoso, 2016-08-05 13:00:54]

Description was changed from

==========
[x64] Zero/Sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16-bit value to a 32-bit register,
then zero/sign-extend from that register to a 64-bit one. Now we replace that
pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org
==========

[epertoso, 2016-08-05 13:01:56]

Patchset #1 (id:1) has been deleted

[epertoso, 2016-08-05 13:02:09]

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

[commit-bot: I haz the power, 2016-08-05 13:02:16]

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

[Benedikt Meurer, 2016-08-05 13:27:09]

lgtm

[commit-bot: I haz the power, 2016-08-05 13:29:06]

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

[commit-bot: I haz the power, 2016-08-05 13:29:07]

Dry run: This issue passed the CQ dry run.

[epertoso, 2016-08-05 13:32:05]

The CQ bit was checked by epertoso@chromium.org

[commit-bot: I haz the power, 2016-08-05 13:32:13]

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, 2016-08-05 13:33:54]

Description was changed from

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org
==========

[commit-bot: I haz the power, 2016-08-05 13:33:55]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2016-08-05 13:34:31]

Description was changed from

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

[commit-bot: I haz the power, 2016-08-05 13:34:32]

Patchset 1 (id:??) landed as
https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}

[Michael Achenbach, 2016-08-05 14:27:08]

A revert of this CL (patchset #1 id:20001) has been created in
https://codereview.chromium.org/2221473002/ by machenbach@chromium.org.

The reason for reverting is: Breaks tree:
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20debug/buil....

[epertoso, 2016-08-08 09:26:12]

Description was changed from

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

[epertoso, 2016-08-08 09:26:26]

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

[commit-bot: I haz the power, 2016-08-08 09:26:35]

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

[Benedikt Meurer, 2016-08-08 09:30:15]

lgtm

[commit-bot: I haz the power, 2016-08-08 09:55:03]

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

[commit-bot: I haz the power, 2016-08-08 09:55:04]

Dry run: This issue passed the CQ dry run.

[epertoso, 2016-08-08 09:57:16]

The CQ bit was checked by epertoso@chromium.org

[commit-bot: I haz the power, 2016-08-08 09:57:24]

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, 2016-08-08 09:59:23]

Description was changed from

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

[commit-bot: I haz the power, 2016-08-08 09:59:25]

Committed patchset #2 (id:40001)

[commit-bot: I haz the power, 2016-08-08 10:00:52]

Description was changed from

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Cr-Commit-Position: refs/heads/master@{#38388}
==========

to

==========
[x64] Zero/sign-extend loads to 64-bit registers.

Before this change we would first load an 8/16/32-bit value from memory into a
32-bit register, then zero/sign-extend from that register to a 64-bit one. Now
we replace that pattern with a single movsx/movzx.

Ported from http://crrev.com/2183923003

R=bmeurer@chromium.org

Committed: https://crrev.com/4abecb7a27bd5fa073d0ff5fadb0c2bb248ef9f4
Committed: https://crrev.com/b79d7b0486779cea1af6ec17b2fe468e6973fd38
Cr-Original-Commit-Position: refs/heads/master@{#38388}
Cr-Commit-Position: refs/heads/master@{#38428}
==========

[commit-bot: I haz the power, 2016-08-08 10:00:53]

Patchset 2 (id:??) landed as
https://crrev.com/b79d7b0486779cea1af6ec17b2fe468e6973fd38
Cr-Commit-Position: refs/heads/master@{#38428}