[turbofan] Centralize splitting for memory operands.

[turbofan] Centralize splitting for memory operands.

This addresses an issue where the at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.

Verified locally that v8:4508 is addressed by this. Also, this fixes
the failures that required the revert
5308a999eb3540c3ca19d4ba08d788a4970431e8. See trybots at
issue 1425533002.

R=bmeurer@chromium.org,jarin@chromium.org
BUG=v8:4508
LOG=n

Committed: https://crrev.com/0b0249582a7dd595cef62eb8897449ac1627d737
Cr-Commit-Position: refs/heads/master@{#31544}

[Mircea Trofin, 2015-10-26 02:35:07]

Description was changed from

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the consistent, at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.



BUG= v8:4508

patch from issue 1425533002 at patchset 60001
(http://crrev.com/1425533002#ps60001)
==========

to

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the consistent, at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.



BUG= v8:4508

patch from issue 1425533002 at patchset 60001
(http://crrev.com/1425533002#ps60001)
==========

[Mircea Trofin, 2015-10-26 02:35:07]

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

[Mircea Trofin, 2015-10-26 02:39:49]

Description was changed from

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the consistent, at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.



BUG= v8:4508

patch from issue 1425533002 at patchset 60001
(http://crrev.com/1425533002#ps60001)
==========

to

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.

Verified locally that v8:4508 is addressed by this. Also, this fixes  
the failures that required the revert 
5308a999eb3540c3ca19d4ba08d788a4970431e8. See trybots at 
issue 1425533002.

BUG= v8:4508

patch from issue 1425533002 at patchset 60001
(http://crrev.com/1425533002#ps60001)
==========

[Benedikt Meurer, 2015-10-26 04:39:45]

Description was changed from

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.

Verified locally that v8:4508 is addressed by this. Also, this fixes  
the failures that required the revert 
5308a999eb3540c3ca19d4ba08d788a4970431e8. See trybots at 
issue 1425533002.

BUG= v8:4508

patch from issue 1425533002 at patchset 60001
(http://crrev.com/1425533002#ps60001)
==========

to

==========
[turbofan] Centralize splitting for memory operands.

This addresses an issue where the at-start splitting used
in the splintering mechanism was in conflict with the mechanics
used in linear allocator, in particular in the initial split/spill of
ranges for memory operands. We are already doing a split-at-start in
Greedy, so this change centralizes that to the base RegisterAllocator.

Verified locally that v8:4508 is addressed by this. Also, this fixes  
the failures that required the revert 
5308a999eb3540c3ca19d4ba08d788a4970431e8. See trybots at 
issue 1425533002.

R=bmeurer@chromium.org,jarin@chromium.org
BUG= v8:4508
LOG=n
==========

[Benedikt Meurer, 2015-10-26 04:40:55]

LGTM.

[Benedikt Meurer, 2015-10-26 04:41:02]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-10-26 04:41:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1426583002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1426583002/1

[commit-bot: I haz the power, 2015-10-26 05:02:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-26 05:03:06]

Patchset 1 (id:??) landed as
https://crrev.com/0b0249582a7dd595cef62eb8897449ac1627d737
Cr-Commit-Position: refs/heads/master@{#31544}