[turbofan] Merge group spill ranges.

[turbofan] Merge group spill ranges.

Akin to linear scan's TryReuseSpillForPhi, we attempt to merge the
spill ranges of grouped live ranges (which are phi inputs and output),
to avoid inefficient slot-to-slot moves.

BUG=

Committed: https://crrev.com/7864c35a76ee490d1676168d51ef6c8ca3ece14b
Cr-Commit-Position: refs/heads/master@{#30833}

[Mircea Trofin, 2015-09-18 04:56:54]

Patchset #1 (id:1) has been deleted

[Mircea Trofin, 2015-09-18 05:05:28]

mtrofin@chromium.org changed reviewers:
+ bmeurer@chromium.org, jarin@chromium.org

[Benedikt Meurer, 2015-09-18 06:08:35]

bmeurer@chromium.org changed required reviewers:
+ jarin@chromium.org

[Benedikt Meurer, 2015-09-18 06:08:36]

LGTM from my side.

https://codereview.chromium.org/1353023003/diff/40001/src/compiler/greedy-all...
File src/compiler/greedy-allocator.cc (right):

https://codereview.chromium.org/1353023003/diff/40001/src/compiler/greedy-all...
src/compiler/greedy-allocator.cc:491: if (!CanProcessRange(top) ||
!top->is_phi() || top->group() == nullptr)
Style nit: Add { and }

[Jarin, 2015-09-18 07:14:52]

lgtm

[Mircea Trofin, 2015-09-18 15:35:02]

The CQ bit was checked by mtrofin@chromium.org

[Mircea Trofin, 2015-09-18 15:35:03]

The patchset sent to the CQ was uploaded after l-g-t-m from bmeurer@chromium.org
Link to the patchset: https://codereview.chromium.org/1353023003/#ps60001
(title: " ")

[commit-bot: I haz the power, 2015-09-18 15:35:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1353023003/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1353023003/60001

[Mircea Trofin, 2015-09-18 15:35:35]

https://codereview.chromium.org/1353023003/diff/40001/src/compiler/greedy-all...
File src/compiler/greedy-allocator.cc (right):

https://codereview.chromium.org/1353023003/diff/40001/src/compiler/greedy-all...
src/compiler/greedy-allocator.cc:491: if (!CanProcessRange(top) ||
!top->is_phi() || top->group() == nullptr)
On 2015/09/18 06:08:36, Benedikt Meurer wrote:
> Style nit: Add { and }

Done.

[commit-bot: I haz the power, 2015-09-18 16:01:57]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2015-09-18 16:02:11]

Patchset 3 (id:??) landed as
https://crrev.com/7864c35a76ee490d1676168d51ef6c8ca3ece14b
Cr-Commit-Position: refs/heads/master@{#30833}