[arm] Avoid unnecessary branches in array constructor stubs.

[arm] Avoid unnecessary branches in array constructor stubs.

R=ulan@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=18427

[Benedikt Meurer, 2013-12-12 10:08:22]

Hey Ulan,
Here's another one to avoid unnecessary branches in code stubs.
PTAL
-- Benedikt

[ulan, 2013-12-12 10:16:00]

lgtm

[Rodolph Perfetta, 2013-12-12 10:19:43]

https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (right):

https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc#ne...
src/arm/code-stubs-arm.cc:5931: __ tst(r0, r0);
cmp r0, #0

[Benedikt Meurer, 2013-12-12 10:34:28]

https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc
File src/arm/code-stubs-arm.cc (right):

https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc#ne...
src/arm/code-stubs-arm.cc:5931: __ tst(r0, r0);
Thanks for the hint. Got rid of this test completely using just one cmp r0, #1
with one lo for the no args case and one hi for the n args case, falling through
to the single arg case.

[Rodolph Perfetta, 2013-12-12 11:13:48]

On 2013/12/12 10:34:28, Benedikt Meurer wrote:
> https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc
> File src/arm/code-stubs-arm.cc (right):
> 
>
https://codereview.chromium.org/113863002/diff/1/src/arm/code-stubs-arm.cc#ne...
> src/arm/code-stubs-arm.cc:5931: __ tst(r0, r0);
> Thanks for the hint. Got rid of this test completely using just one cmp r0, #1
> with one lo for the no args case and one hi for the n args case, falling
through
> to the single arg case.

nice.

[Benedikt Meurer, 2014-01-02 06:18:08]

Committed patchset #2 manually as r18427 (presubmit successful).