S390: Fix LA overflow in return sequence

S390: Fix LA overflow in return sequence

In test regress-492.js, the return sequence require to adjust sp to
sp + 513 * 8 bytes, which causes overflow of the displacement in LA.

R=michael_dawson@ca.ibm.com,mbrandy@us.ibm.com,joransiu@ca.ibm.com
BUG=

Committed: https://crrev.com/34c4e27e91a1122b97be937241b5b668972c1968
Cr-Commit-Position: refs/heads/master@{#35267}

[john.yan, 2016-04-05 14:36:28]

PTAL

[JoranSiu, 2016-04-05 14:39:41]

https://codereview.chromium.org/1865443002/diff/1/src/s390/macro-assembler-s3...
File src/s390/macro-assembler-s390.cc (right):

https://codereview.chromium.org/1865443002/diff/1/src/s390/macro-assembler-s3...
src/s390/macro-assembler-s390.cc:159: la(sp, MemOperand(sp, count *
kPointerSize));
Should we just replace count*kPointerSize with total?

https://codereview.chromium.org/1865443002/diff/1/src/s390/macro-assembler-s3...
src/s390/macro-assembler-s390.cc:163: mov(r0, Operand(count));
Should Operand be (total) here?

https://codereview.chromium.org/1865443002/diff/1/src/s390/macro-assembler-s3...
src/s390/macro-assembler-s390.cc:164: SubP(sp, r0);
This should be Add?     I think we can use the AddP(sp, Operand(count *
kPointerSize)) instead.

[JoranSiu, 2016-04-05 14:49:53]

lgtm

[john.yan, 2016-04-05 14:50:56]

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

[commit-bot: I haz the power, 2016-04-05 14:51:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1865443002/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1865443002/60001

[commit-bot: I haz the power, 2016-04-05 15:16:14]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-04-05 15:17:02]

Description was changed from

==========
S390: Fix LA overflow in return sequence

In test regress-492.js, the return sequence require to adjust sp to
sp + 513 * 8 bytes, which causes overflow of the displacement in LA.

R=michael_dawson@ca.ibm.com,mbrandy@us.ibm.com,joransiu@ca.ibm.com
BUG=
==========

to

==========
S390: Fix LA overflow in return sequence

In test regress-492.js, the return sequence require to adjust sp to
sp + 513 * 8 bytes, which causes overflow of the displacement in LA.

R=michael_dawson@ca.ibm.com,mbrandy@us.ibm.com,joransiu@ca.ibm.com
BUG=

Committed: https://crrev.com/34c4e27e91a1122b97be937241b5b668972c1968
Cr-Commit-Position: refs/heads/master@{#35267}
==========

[commit-bot: I haz the power, 2016-04-05 15:17:03]

Patchset 4 (id:??) landed as
https://crrev.com/34c4e27e91a1122b97be937241b5b668972c1968
Cr-Commit-Position: refs/heads/master@{#35267}