Use stack locations instead of register for binary Smi operations when possible.

Use stack locations instead of register for binary Smi operations when possible.

R=fschneider@google.com

Committed: https://code.google.com/p/dart/source/detail?r=23249

[Florian Schneider, 2013-05-28 10:09:37]

LGTM.

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
File runtime/vm/intermediate_language_ia32.cc (right):

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
runtime/vm/intermediate_language_ia32.cc:2319: summary->set_in(1,
Location::Any());
We also have Location::PrefersRegister() as an alternative. The difference is
that if there is a free register and the value is spilled, it will go into the
free register. If all registers are occupied, it will be on the stack.

I think PrefersRegister() would be better than Any(), but it should be confirmed
with a measurement.

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
File runtime/vm/intermediate_language_x64.cc (right):

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
runtime/vm/intermediate_language_x64.cc:2327: summary->set_in(1,
Location::Any());
Same comment as on ia32.

[srdjan, 2013-05-28 10:39:01]

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
File runtime/vm/intermediate_language_ia32.cc (right):

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
runtime/vm/intermediate_language_ia32.cc:2319: summary->set_in(1,
Location::Any());
On 2013/05/28 10:09:37, Florian Schneider wrote:
> We also have Location::PrefersRegister() as an alternative. The difference is
> that if there is a free register and the value is spilled, it will go into the
> free register. If all registers are occupied, it will be on the stack.
> 
> I think PrefersRegister() would be better than Any(), but it should be
confirmed
> with a measurement.

Changed to PrefersRegister, no significant difference in performance observed.

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
File runtime/vm/intermediate_language_x64.cc (right):

https://codereview.chromium.org/16126003/diff/7004/runtime/vm/intermediate_la...
runtime/vm/intermediate_language_x64.cc:2327: summary->set_in(1,
Location::Any());
On 2013/05/28 10:09:37, Florian Schneider wrote:
> Same comment as on ia32.

Done.

[srdjan, 2013-05-28 10:44:08]

Committed patchset #4 manually as r23249 (presubmit successful).