Implement simplistic local alias analysis, which will be used in both check elimination and load el…

Implement simplistic local alias analysis, which will be used in both check elimination and load elimination.

BUG=
R=verwaest@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16645

[titzer, 2013-09-11 08:40:03]

PTAL, added an ActualValue() method.

[Toon Verwaest, 2013-09-11 09:05:54]

lgtm with nit

https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysis.h
File src/hydrogen-alias-analysis.h (right):

https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysi...
src/hydrogen-alias-analysis.h:40: };
Can we move this enum into HAliasAnalyzer?

[titzer, 2013-09-11 10:47:08]

On 2013/09/11 09:05:54, Toon Verwaest wrote:
> lgtm with nit
> 
>
https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysis.h
> File src/hydrogen-alias-analysis.h (right):
> 
>
https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysi...
> src/hydrogen-alias-analysis.h:40: };
> Can we move this enum into HAliasAnalyzer?

The thinking was that this is a simple data value that doesn't necessary
"belong" to the HAliasAnalyzer; one doesn't need to have such an analyzer to get
one of the values; I also think it looks nicer to write "HAliasing" instead of
"HAliasAnalyzer::Aliasing".

[titzer, 2013-09-11 10:54:05]

Committed patchset #2 manually as r16645 (presubmit successful).

[Michael Starzinger, 2013-09-12 20:09:08]

Late DBC that I stumbled over while reviewing load-store elimination.

https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysis.h
File src/hydrogen-alias-analysis.h (right):

https://codereview.chromium.org/23516010/diff/4001/src/hydrogen-alias-analysi...
src/hydrogen-alias-analysis.h:90: HValue* ActualValue(HValue* obj) {
Can we move this onto the HValue class? Pretty please! :)