[Turbofan] Revert FP register aliasing support on Arm.

[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202
Committed: https://crrev.com/55b01ccbfc2b80b988ce9cb46b6368d8b4f13039
Cr-Commit-Position: refs/heads/master@{#38151}

[bbudge, 2016-07-25 17:24:14]

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

[commit-bot: I haz the power, 2016-07-25 17:24:15]

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, 2016-07-25 17:27:45]

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

[commit-bot: I haz the power, 2016-07-25 17:27:46]

Dry run: Try jobs failed on following builders:
  v8_linux_arm64_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm64_rel_ng/build...)
  v8_linux_mips64el_compile_rel on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_mips64el_compile_r...)

[bbudge, 2016-07-25 19:48:52]

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

[commit-bot: I haz the power, 2016-07-25 19:48:56]

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

[bbudge, 2016-07-25 19:58:08]

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

[commit-bot: I haz the power, 2016-07-25 19:58:15]

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, 2016-07-25 20:24:00]

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

[commit-bot: I haz the power, 2016-07-25 20:24:01]

Dry run: Try jobs failed on following builders:
  v8_linux_arm_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel_ng/builds/...)
  v8_linux_arm_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel_ng_trigger...)

[bbudge, 2016-07-25 20:47:20]

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

[commit-bot: I haz the power, 2016-07-25 20:47:31]

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

[bbudge, 2016-07-25 20:55:37]

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

[commit-bot: I haz the power, 2016-07-25 20:55:44]

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

[bbudge, 2016-07-25 21:00:09]

bbudge@chromium.org changed reviewers:
+ bmeurer@chromium.org, mtrofin@chromium.org

[bbudge, 2016-07-25 21:00:09]

I attempted to back out just the support for odd-numbered single VFP registers.

[commit-bot: I haz the power, 2016-07-25 21:20:18]

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

[commit-bot: I haz the power, 2016-07-25 21:20:19]

Dry run: This issue passed the CQ dry run.

[bbudge, 2016-07-25 23:04:53]

Description was changed from

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

LOG=N
BUG=V8:4124, V8:5202
==========

to

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202
==========

[bbudge, 2016-07-26 18:56:59]

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

[commit-bot: I haz the power, 2016-07-26 18:57:09]

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, 2016-07-26 19:24:32]

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

[commit-bot: I haz the power, 2016-07-26 19:24:33]

Dry run: This issue passed the CQ dry run.

[Mircea Trofin, 2016-07-27 23:29:31]

lgtm

https://codereview.chromium.org/2176173003/diff/100001/src/compiler/register-...
File src/compiler/register-allocator.cc (right):

https://codereview.chromium.org/2176173003/diff/100001/src/compiler/register-...
src/compiler/register-allocator.cc:79: return 8;
isn't there a constant we could use instead of "8"?

[bbudge, 2016-07-28 13:23:34]

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

[commit-bot: I haz the power, 2016-07-28 13:23:37]

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, 2016-07-28 13:56:34]

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

[commit-bot: I haz the power, 2016-07-28 13:56:35]

Dry run: This issue passed the CQ dry run.

[bbudge, 2016-07-29 00:45:39]

https://codereview.chromium.org/2176173003/diff/100001/src/compiler/register-...
File src/compiler/register-allocator.cc (right):

https://codereview.chromium.org/2176173003/diff/100001/src/compiler/register-...
src/compiler/register-allocator.cc:79: return 8;
On 2016/07/27 23:29:31, Mircea Trofin wrote:
> isn't there a constant we could use instead of "8"?

Fixed here and the rest too.

[bbudge, 2016-07-29 00:46:00]

The CQ bit was checked by bbudge@chromium.org

[bbudge, 2016-07-29 00:46:00]

The patchset sent to the CQ was uploaded after l-g-t-m from mtrofin@chromium.org
Link to the patchset: https://codereview.chromium.org/2176173003/#ps140001
(title: "Rebase.")

[commit-bot: I haz the power, 2016-07-29 00:46:02]

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, 2016-07-29 00:47:50]

Description was changed from

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202
==========

to

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202
==========

[commit-bot: I haz the power, 2016-07-29 00:47:51]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2016-07-29 00:51:08]

Description was changed from

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202
==========

to

==========
[Turbofan] Revert FP register aliasing support on Arm.
- Changes register allocation to only use even numbered registers on Arm.
- Turns on float32 testing in test-gap-resolver.cc.

This is effectively a revert of:
https://codereview.chromium.org/2086653003/

LOG=N
BUG=V8:4124, V8:5202

Committed: https://crrev.com/55b01ccbfc2b80b988ce9cb46b6368d8b4f13039
Cr-Commit-Position: refs/heads/master@{#38151}
==========

[commit-bot: I haz the power, 2016-07-29 00:51:09]

Patchset 8 (id:??) landed as
https://crrev.com/55b01ccbfc2b80b988ce9cb46b6368d8b4f13039
Cr-Commit-Position: refs/heads/master@{#38151}