Refactor Hydrogen GVN into an HPhase and use the phase zone.

Refactor Hydrogen GVN into an HPhase and use the phase zone.
    
The HGlobalValueNumberer class is renamed to HGlobalValueNumberingPhase,
following the naming scheme suggested by danno@chromium.org in
https://codereview.chromium.org/17458002
    
The GVN phase now uses the phase zone for all its allocations.
    
Depends upon https://codereview.chromium.org/18022002

R=danno@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=15353

[danno, 2013-06-25 15:20:54]

https://codereview.chromium.org/17657004/diff/1/src/hydrogen-gvn.h
File src/hydrogen-gvn.h (right):

https://codereview.chromium.org/17657004/diff/1/src/hydrogen-gvn.h#newcode82
src/hydrogen-gvn.h:82: HGlobalValueNumberingPhase(HGraph* graph, Zone* zone);
Why do you need to pass the zone in? Shouldn't you be able to get it from
graph()->info()->phase_zone()?

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h
File src/hydrogen.h (right):

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h#newcode431
src/hydrogen.h:431: void Run() { Phase phase(this, info()->phase_zone());
phase.Run(); }
Isn't this from another CL?

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h#newcode1966
src/hydrogen.h:1966: HPhase(const char* name, HGraph* graph, Zone* zone);
again, why do you need to pass the zone in? Either you need the graph zone (with
graph->zone()) or the phase zone (graph->info()->phase_zone()). Either way, you
shouldn't have to pass it in explicitly.

[Benedikt Meurer, 2013-06-27 08:20:04]

Rebased on https://codereview.chromium.org/18022002 using the phase zone now
found in HPhase (actually CompilationPhase).

https://codereview.chromium.org/17657004/diff/1/src/hydrogen-gvn.h
File src/hydrogen-gvn.h (right):

https://codereview.chromium.org/17657004/diff/1/src/hydrogen-gvn.h#newcode82
src/hydrogen-gvn.h:82: HGlobalValueNumberingPhase(HGraph* graph, Zone* zone);
On 2013/06/25 15:20:54, danno wrote:
> Why do you need to pass the zone in? Shouldn't you be able to get it from
> graph()->info()->phase_zone()?

Done. Using the HPhase zone.

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h
File src/hydrogen.h (right):

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h#newcode431
src/hydrogen.h:431: void Run() { Phase phase(this, info()->phase_zone());
phase.Run(); }
On 2013/06/25 15:20:54, danno wrote:
> Isn't this from another CL?

Done.

https://codereview.chromium.org/17657004/diff/1/src/hydrogen.h#newcode1966
src/hydrogen.h:1966: HPhase(const char* name, HGraph* graph, Zone* zone);
On 2013/06/25 15:20:54, danno wrote:
> again, why do you need to pass the zone in? Either you need the graph zone
(with
> graph->zone()) or the phase zone (graph->info()->phase_zone()). Either way,
you
> shouldn't have to pass it in explicitly.

Done.

[danno, 2013-06-27 13:04:30]

LGTM with a nit

https://codereview.chromium.org/17657004/diff/8001/src/hydrogen-gvn.cc
File src/hydrogen-gvn.cc (right):

https://codereview.chromium.org/17657004/diff/8001/src/hydrogen-gvn.cc#newcod...
src/hydrogen-gvn.cc:615: GVNFlagSet
HGlobalValueNumberingPhase::CollectSideEffectsOnPathsToDominatedBlock
Insert a line break after GVNFlagSet rather than putting the ( on the next line

[Benedikt Meurer, 2013-06-27 13:09:15]

Committed patchset #4 manually as r15353 (presubmit successful).