MIPS[64]: Disable fusion multiple-accumulate instructions

MIPS[64]: Disable fusion multiple-accumulate instructions

MIPS[64]R6 supports only fusion multiply-accumulate instructions, and using
these causes failures of several tests that expect exact floating-point
results. Therefore we disable fusion multiply-accumulate in both emitted and
compiled code on R6.

TEST=cctest/test-run-machops/RunFloat64MulAndFloat64Add1,mjsunit/es6/math-expm1.js
mjsunit/es6/math-fround.js,mjsunit/compiler/multiply-add.js

BUG=

Review-Url: https://codereview.chromium.org/2569683002
Cr-Commit-Position: refs/heads/master@{#41717}
Committed: https://chromium.googlesource.com/v8/v8/+/ee7281f8ff8122953ed843f0815b8bbe59eacd93

[ivica.bogosavljevic, 2016-12-12 13:12:35]

ivica.bogosavljevic@imgtec.com changed reviewers:
+ dusan.simicic@imgtec.com, miran.karic@imgtec.com, vogelheim@chromium.org

[ivica.bogosavljevic, 2016-12-12 13:12:36]

PTAL

[Ilija.Pavlovic1, 2016-12-13 12:48:14]

ilija.pavlovic@imgtec.com changed reviewers:
+ Ilija.Pavlovic@imgtec.com

[Ilija.Pavlovic1, 2016-12-13 12:48:14]

lgtm

[miran.karic, 2016-12-14 13:05:13]

miran.karic@imgtec.com changed reviewers:
+ Miran.Karic@imgtec.com, ilija.pavlovic@imgtec.com
- Ilija.Pavlovic@imgtec.com

[miran.karic, 2016-12-14 13:05:13]

miran.karic@imgtec.com changed reviewers:
+ Miran.Karic@imgtec.com, ilija.pavlovic@imgtec.com
- Ilija.Pavlovic@imgtec.com

[miran.karic, 2016-12-14 13:05:14]

lgtm

[miran.karic, 2016-12-14 13:05:14]

lgtm

lgtm

[ivica.bogosavljevic, 2016-12-15 09:49:06]

The CQ bit was checked by ivica.bogosavljevic@imgtec.com to run a CQ dry run

[commit-bot: I haz the power, 2016-12-15 09:49:14]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[ivica.bogosavljevic, 2016-12-15 09:57:28]

ivica.bogosavljevic@imgtec.com changed reviewers:
+ bmeurer@chromium.org, machenbach@chromium.org
- Miran.Karic@imgtec.com

[ivica.bogosavljevic, 2016-12-15 09:57:28]

I need lght from the owners of cctest.gyp and BUILD.gn in order to land this
change

[commit-bot: I haz the power, 2016-12-15 10:16:17]

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

[commit-bot: I haz the power, 2016-12-15 10:16:18]

Dry run: This issue passed the CQ dry run.

[Michael Achenbach, 2016-12-15 10:40:07]

lgtm

[ivica.bogosavljevic, 2016-12-15 11:47:14]

The CQ bit was checked by ivica.bogosavljevic@imgtec.com

[commit-bot: I haz the power, 2016-12-15 11:47:21]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-15 11:50:13]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1481802434680620, "parent_rev":
"7c43fcb285dc3a009e4116831f8ab3d8433cde52", "commit_rev":
"ee7281f8ff8122953ed843f0815b8bbe59eacd93"}

[commit-bot: I haz the power, 2016-12-15 11:50:23]

Description was changed from

==========
MIPS[64]: Disable fusion multiple-accumulate instructions

MIPS[64]R6 supports only fusion multiply-accumulate instructions, and using
these causes failures of several tests that expect exact floating-point
results. Therefore we disable fusion multiply-accumulate in both emitted and
compiled code on R6.

TEST=cctest/test-run-machops/RunFloat64MulAndFloat64Add1,mjsunit/es6/math-expm1.js
mjsunit/es6/math-fround.js,mjsunit/compiler/multiply-add.js

BUG=
==========

to

==========
MIPS[64]: Disable fusion multiple-accumulate instructions

MIPS[64]R6 supports only fusion multiply-accumulate instructions, and using
these causes failures of several tests that expect exact floating-point
results. Therefore we disable fusion multiply-accumulate in both emitted and
compiled code on R6.

TEST=cctest/test-run-machops/RunFloat64MulAndFloat64Add1,mjsunit/es6/math-expm1.js
mjsunit/es6/math-fround.js,mjsunit/compiler/multiply-add.js

BUG=

Review-Url: https://codereview.chromium.org/2569683002
Cr-Commit-Position: refs/heads/master@{#41717}
Committed:
https://chromium.googlesource.com/v8/v8/+/ee7281f8ff8122953ed843f0815b8bbe59e...
==========

[commit-bot: I haz the power, 2016-12-15 11:50:24]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/ee7281f8ff8122953ed843f0815b8bbe59e...