Simplify mint comparison code on ARM.

Simplify mint comparison code on ARM.

R=zra@google.com

Committed: https://code.google.com/p/dart/source/detail?r=42053

[regis, 2014-12-01 21:04:24]

regis@google.com changed reviewers:
+ johnmccutchan@google.com, zra@google.com

[zra, 2014-12-01 21:18:18]

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
File runtime/vm/intermediate_language_arm.cc (right):

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
runtime/vm/intermediate_language_arm.cc:611: __ cmp(left_lo, Operand(right_lo));
Do you need to branch to a label here? Maybe we need a test for this case.

[regis, 2014-12-01 22:19:51]

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
File runtime/vm/intermediate_language_arm.cc (right):

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
runtime/vm/intermediate_language_arm.cc:611: __ cmp(left_lo, Operand(right_lo));
On 2014/12/01 21:18:18, zra wrote:
> Do you need to branch to a label here? Maybe we need a test for this case.

No, we only return the condition. The branch itself will be emitted on line 876.

[zra, 2014-12-01 22:34:47]

lgtm

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
File runtime/vm/intermediate_language_arm.cc (right):

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
runtime/vm/intermediate_language_arm.cc:611: __ cmp(left_lo, Operand(right_lo));
On 2014/12/01 22:19:51, regis wrote:
> On 2014/12/01 21:18:18, zra wrote:
> > Do you need to branch to a label here? Maybe we need a test for this case.
> 
> No, we only return the condition. The branch itself will be emitted on line
876.
> 

Ah, I see =) Didn't notice the call to EmitBranchOnCondition there. So if the
call to EmitBranchOnCondition only handles this case, and always results in:

__b(labels.true_label, lo_cond);

it might be easier to follow if that was just inlined here. Up to you.

[regis, 2014-12-01 22:44:00]

Thanks!

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
File runtime/vm/intermediate_language_arm.cc (right):

https://codereview.chromium.org/766313002/diff/1/runtime/vm/intermediate_lang...
runtime/vm/intermediate_language_arm.cc:611: __ cmp(left_lo, Operand(right_lo));
On 2014/12/01 22:34:47, zra wrote:
> On 2014/12/01 22:19:51, regis wrote:
> > On 2014/12/01 21:18:18, zra wrote:
> > > Do you need to branch to a label here? Maybe we need a test for this case.
> > 
> > No, we only return the condition. The branch itself will be emitted on line
> 876.
> > 
> 
> Ah, I see =) Didn't notice the call to EmitBranchOnCondition there. So if the
> call to EmitBranchOnCondition only handles this case, and always results in:
> 
> __b(labels.true_label, lo_cond);
> 
> it might be easier to follow if that was just inlined here. Up to you.

I prefer to leave the code in sync with other platforms.

[regis, 2014-12-01 22:44:18]

Committed patchset #1 (id:1) manually as r42053 (presubmit successful).