PPC: [turbofan] Optimize loading 64-bit SMIs.

PPC: [turbofan] Optimize loading 64-bit SMIs.

Especially when loading and untagging SMIs within code stubs,
instances of the following pattern appear in the generated code:

    ld    <dst>, <offset>(<base>)
    sradi <dst>,<dst>,32

This CL changes that code to:

    lwa   <dst>, <SmiWordOffset(offset)>(<base>)

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/6ae6d3f8b70e05eb5dd0cdaff77b530486c08ad2
Cr-Commit-Position: refs/heads/master@{#35216}

[MTBrandyberry, 2016-04-01 18:19:20]

PTAL

[MTBrandyberry, 2016-04-01 18:19:24]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2016-04-01 18:19:33]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1855533002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1855533002/1

[commit-bot: I haz the power, 2016-04-01 18:39:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-01 18:39:46]

Dry run: This issue passed the CQ dry run.

[john.yan, 2016-04-01 18:55:21]

lgtm

[MTBrandyberry, 2016-04-01 19:04:57]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2016-04-01 19:05:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1855533002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1855533002/1

[commit-bot: I haz the power, 2016-04-01 19:07:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-01 19:08:59]

Description was changed from

==========
PPC: [turbofan] Optimize loading 64-bit SMIs.

Especially when loading and untagging SMIs within code stubs,
instances of the following pattern appear in the generated code:

    ld    <dst>, <offset>(<base>)
    sradi <dst>,<dst>,32

This CL changes that code to:

    lwa   <dst>, <SmiWordOffset(offset)>(<base>)

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
==========

to

==========
PPC: [turbofan] Optimize loading 64-bit SMIs.

Especially when loading and untagging SMIs within code stubs,
instances of the following pattern appear in the generated code:

    ld    <dst>, <offset>(<base>)
    sradi <dst>,<dst>,32

This CL changes that code to:

    lwa   <dst>, <SmiWordOffset(offset)>(<base>)

R=joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/6ae6d3f8b70e05eb5dd0cdaff77b530486c08ad2
Cr-Commit-Position: refs/heads/master@{#35216}
==========

[commit-bot: I haz the power, 2016-04-01 19:08:59]

Patchset 1 (id:??) landed as
https://crrev.com/6ae6d3f8b70e05eb5dd0cdaff77b530486c08ad2
Cr-Commit-Position: refs/heads/master@{#35216}