Flow engine fixes: unreachable block processing, state merging.

Flow engine fixes: unreachable block processing, state merging.

R=titzer@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=18885

[Igor Sheludko, 2014-01-21 13:39:32]

PTAL

[titzer, 2014-01-27 12:42:31]

lgtm other than below comments.

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-check-eliminati...
File src/hydrogen-check-elimination.cc (right):

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-check-eliminati...
src/hydrogen-check-elimination.cc:176: void Merge(HBasicBlock* succ,
HCheckTable* that,
Please keep the interface that it returns the "new" state. The idea being that
some implementations of state might be immutable (e.g. we planned on using this
for escape analysis as well).

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-flow-engine.h
File src/hydrogen-flow-engine.h (right):

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-flow-engine.h#n...
src/hydrogen-flow-engine.h:158: StateAt(succ)->Merge(succ, state, block, zone_);
You will want to keep SetStateAt() as per previous comment.

[Igor Sheludko, 2014-01-28 16:55:41]

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-check-eliminati...
File src/hydrogen-check-elimination.cc (right):

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-check-eliminati...
src/hydrogen-check-elimination.cc:176: void Merge(HBasicBlock* succ,
HCheckTable* that,
On 2014/01/27 12:42:32, titzer wrote:
> Please keep the interface that it returns the "new" state. The idea being that
> some implementations of state might be immutable (e.g. we planned on using
this
> for escape analysis as well).

Done.

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-flow-engine.h
File src/hydrogen-flow-engine.h (right):

https://codereview.chromium.org/144013003/diff/1/src/hydrogen-flow-engine.h#n...
src/hydrogen-flow-engine.h:158: StateAt(succ)->Merge(succ, state, block, zone_);
On 2014/01/27 12:42:32, titzer wrote:
> You will want to keep SetStateAt() as per previous comment.

Done.

[Igor Sheludko, 2014-01-28 16:57:48]

Committed patchset #2 manually as r18885 (presubmit successful).