PPC: Get rid of AllocationFlags::TAG_OBJECT

PPC: Get rid of AllocationFlags::TAG_OBJECT

Port ef49c6b11a7a382909c2fbe1c5f38a8c3e1e4fb8

Original commit message:

    Default (and only way) is now to retrieve a tagged object.

R=mlippautz@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=chromium:606711
LOG=N

Committed: https://crrev.com/9bf7a31a8ced123b8bd051f3ef39625104a1124f
Cr-Commit-Position: refs/heads/master@{#35829}

[JaideepBajwa, 2016-04-26 23:55:45]

PTAL

[Michael Lippautz, 2016-04-27 07:43:00]

lgtm from my side, thanks a lot!

[MTBrandyberry, 2016-04-27 14:13:06]

Did you see test failures as a result of this bug?

https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc
File src/ppc/codegen-ppc.cc (right):

https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc#newc...
src/ppc/codegen-ppc.cc:324: __ subi(array, array, Operand(kHeapObjectTag));
The code below assume array is tagged.  This line should be removed.

[JaideepBajwa, 2016-04-27 14:20:53]

On 2016/04/27 14:13:06, MTBrandyberry wrote:
> Did you see test failures as a result of this bug?
> 
> https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc
> File src/ppc/codegen-ppc.cc (right):
> 
>
https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc#newc...
> src/ppc/codegen-ppc.cc:324: __ subi(array, array, Operand(kHeapObjectTag));
> The code below assume array is tagged.  This line should be removed.

no I didn't see any failures, I had a clean build and all the unit test passed
(on ppc64le)

[Michael Lippautz, 2016-04-27 14:28:10]

On 2016/04/27 14:20:53, bjaideep wrote:
> On 2016/04/27 14:13:06, MTBrandyberry wrote:
> > Did you see test failures as a result of this bug?
> > 
> > https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc
> > File src/ppc/codegen-ppc.cc (right):
> > 
> >
>
https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc#newc...
> > src/ppc/codegen-ppc.cc:324: __ subi(array, array, Operand(kHeapObjectTag));
> > The code below assume array is tagged.  This line should be removed.
> 
> no I didn't see any failures, I had a clean build and all the unit test passed
> (on ppc64le)

fyi: on the archs maintained by us I definitely observed failures when screwing
up ElementsTransitionGenerator::GenerateDoubleToObject. 

By "unit test" you only mean unittests, or also cctest and mjsunit ?

[JaideepBajwa, 2016-04-27 14:36:10]

On 2016/04/27 14:28:10, Michael Lippautz wrote:
> On 2016/04/27 14:20:53, bjaideep wrote:
> > On 2016/04/27 14:13:06, MTBrandyberry wrote:
> > > Did you see test failures as a result of this bug?
> > > 
> > > https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc
> > > File src/ppc/codegen-ppc.cc (right):
> > > 
> > >
> >
>
https://codereview.chromium.org/1917353002/diff/1/src/ppc/codegen-ppc.cc#newc...
> > > src/ppc/codegen-ppc.cc:324: __ subi(array, array,
Operand(kHeapObjectTag));
> > > The code below assume array is tagged.  This line should be removed.
> > 
> > no I didn't see any failures, I had a clean build and all the unit test
passed
> > (on ppc64le)
> 
> fyi: on the archs maintained by us I definitely observed failures when
screwing
> up ElementsTransitionGenerator::GenerateDoubleToObject. 
> 
> By "unit test" you only mean unittests, or also cctest and mjsunit ?

Yes, I meant including cctest and mjsunit (all testcases run by
tools/run-tests.py)

[MTBrandyberry, 2016-04-27 16:51:15]

lgtm

[JaideepBajwa, 2016-04-27 16:51:40]

The CQ bit was checked by bjaideep@ca.ibm.com

[JaideepBajwa, 2016-04-27 16:51:41]

The patchset sent to the CQ was uploaded after l-g-t-m from
mlippautz@chromium.org
Link to the patchset: https://codereview.chromium.org/1917353002/#ps20001
(title: "removed subi instruction as subsequent addi handled kHeapObjectTag")

[commit-bot: I haz the power, 2016-04-27 16:51:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1917353002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1917353002/20001

[commit-bot: I haz the power, 2016-04-27 17:09:16]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-05-01 22:01:19]

Description was changed from

==========
PPC: Get rid of AllocationFlags::TAG_OBJECT

Port ef49c6b11a7a382909c2fbe1c5f38a8c3e1e4fb8

Original commit message:

    Default (and only way) is now to retrieve a tagged object.

R=mlippautz@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=chromium:606711
LOG=N
==========

to

==========
PPC: Get rid of AllocationFlags::TAG_OBJECT

Port ef49c6b11a7a382909c2fbe1c5f38a8c3e1e4fb8

Original commit message:

    Default (and only way) is now to retrieve a tagged object.

R=mlippautz@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com

BUG=chromium:606711
LOG=N

Committed: https://crrev.com/9bf7a31a8ced123b8bd051f3ef39625104a1124f
Cr-Commit-Position: refs/heads/master@{#35829}
==========

[commit-bot: I haz the power, 2016-05-01 22:01:20]

Patchset 2 (id:??) landed as
https://crrev.com/9bf7a31a8ced123b8bd051f3ef39625104a1124f
Cr-Commit-Position: refs/heads/master@{#35829}