Implement global load elimination based on flow engine.

Implement global load elimination based on flow engine.

BUG=
R=mvstanton@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17273

[mvstanton, 2013-10-17 10:32:55]

Hi Ben,
I'd like to see another test, but looks really good.
thx,
--Michael

https://codereview.chromium.org/27148004/diff/1/test/mjsunit/compiler/load-el...
File test/mjsunit/compiler/load-elimination-global.js (right):

https://codereview.chromium.org/27148004/diff/1/test/mjsunit/compiler/load-el...
test/mjsunit/compiler/load-elimination-global.js:92: function test_loop(x) {
Could you have another test (or extend this one) to use a nested loop so the
recursive part of the flow engine on loop effects is exercised to some level?

[titzer, 2013-10-18 09:17:25]

On 2013/10/17 10:32:55, mvstanton wrote:
> Hi Ben,
> I'd like to see another test, but looks really good.
> thx,
> --Michael
> 
>
https://codereview.chromium.org/27148004/diff/1/test/mjsunit/compiler/load-el...
> File test/mjsunit/compiler/load-elimination-global.js (right):
> 
>
https://codereview.chromium.org/27148004/diff/1/test/mjsunit/compiler/load-el...
> test/mjsunit/compiler/load-elimination-global.js:92: function test_loop(x) {
> Could you have another test (or extend this one) to use a nested loop so the
> recursive part of the flow engine on loop effects is exercised to some level?

Done.

[mvstanton, 2013-10-18 13:26:11]

lgtm

[titzer, 2013-10-18 14:28:32]

Committed patchset #2 manually as r17273 (presubmit successful).