X87: Temporary workaround for X87 FPU convert SNaN to QNaN automatically issue.

X87: Temporary workaround for X87 FPU convert SNaN to QNaN automatically issue.

  x87 FPU converts the SNaN to QNaN automatically when loading SNaN from memmory. This function caused v8 x87 port can't distinguish the
  Hole NaN (V8 used SNaN for it) from Javascript visible NaNs (V8 used QNaN for it).

  Many test cases failed in this function for v8 x87 port. It's a big effort to refactor all code of x87 FPU loads value from memmory to
  fix this issue.

  So here's a temporary workaround for it, what's this CL does are:
  1. Removed all previous x87 workaround of this issue.
  2. Used SNaN of MIPS which is a not used QNaN in v8 x87 port as the Hole NaN for v8 x87 port.
  3. This CL is only local to x87 port.

BUG=

Committed: https://crrev.com/22a73e0d854638ca26d8a49434a605f1fde0daf8
Cr-Commit-Position: refs/heads/master@{#36697}

[zhengxing.li, 2016-06-03 07:49:59]

zhengxing.li@intel.com changed reviewers:
+ bmeurer@chromium.org, chunyang.dai@intel.com, weiliang.lin@intel.com

[zhengxing.li, 2016-06-03 07:50:00]

Hi, Benedikt:

we talked about this issue in E-Mail already, please help to review this CL,
thanks!

[Benedikt Meurer, 2016-06-03 07:50:34]

lgtm

[zhengxing.li, 2016-06-03 07:51:30]

On 2016/06/03 07:50:34, Benedikt Meurer wrote:
> lgtm

thanks!

[Weiliang, 2016-06-03 07:54:23]

lgtm

[zhengxing.li, 2016-06-03 08:00:07]

The CQ bit was checked by zhengxing.li@intel.com

[commit-bot: I haz the power, 2016-06-03 08:00:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2033133004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/2033133004/1

[commit-bot: I haz the power, 2016-06-03 08:31:56]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-03 08:33:54]

Description was changed from

==========
X87: Temporary workaround for X87 FPU convert SNaN to QNaN automatically issue.

  x87 FPU converts the SNaN to QNaN automatically when loading SNaN from
memmory. This function caused v8 x87 port can't distinguish the
  Hole NaN (V8 used SNaN for it) from Javascript visible NaNs (V8 used QNaN for
it).

  Many test cases failed in this function for v8 x87 port. It's a big effort to
refactor all code of x87 FPU loads value from memmory to
  fix this issue.

  So here's a temporary workaround for it, what's this CL does are:
  1. Removed all previous x87 workaround of this issue.
  2. Used SNaN of MIPS which is a not used QNaN in v8 x87 port as the Hole NaN
for v8 x87 port.
  3. This CL is only local to x87 port.

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

to

==========
X87: Temporary workaround for X87 FPU convert SNaN to QNaN automatically issue.

  x87 FPU converts the SNaN to QNaN automatically when loading SNaN from
memmory. This function caused v8 x87 port can't distinguish the
  Hole NaN (V8 used SNaN for it) from Javascript visible NaNs (V8 used QNaN for
it).

  Many test cases failed in this function for v8 x87 port. It's a big effort to
refactor all code of x87 FPU loads value from memmory to
  fix this issue.

  So here's a temporary workaround for it, what's this CL does are:
  1. Removed all previous x87 workaround of this issue.
  2. Used SNaN of MIPS which is a not used QNaN in v8 x87 port as the Hole NaN
for v8 x87 port.
  3. This CL is only local to x87 port.

BUG=

Committed: https://crrev.com/22a73e0d854638ca26d8a49434a605f1fde0daf8
Cr-Commit-Position: refs/heads/master@{#36697}
==========

[commit-bot: I haz the power, 2016-06-03 08:33:55]

Patchset 1 (id:??) landed as
https://crrev.com/22a73e0d854638ca26d8a49434a605f1fde0daf8
Cr-Commit-Position: refs/heads/master@{#36697}