X87: [TurboFan] Change the implementation of Float32's NaN comparision's return value in kX87Float3…

X87: [TurboFan] Change the implementation of Float32's NaN comparision's return value in kX87Float32Min and kX87Float32Max.

  The CL 32796(https://codereview.chromium.org/1512023002) adds many Float32 comparision test data which including the NaN comparision.

  As there's no Specification for the return value of NaN comparision, Current x87 will check the Float comparision instruction's first
  operand, if it's NaN, return the second operand. Otherwise, return itself.

  But this conflicts with the Gcc compiler's implementation and cause the RunFloat32MinP and RunFloat32MaxP tests failed.

  For (a < b) comparision, The Gcc compiler will treat the NaN comparision's result same as a GT b and return b.
  The minss sse instruction in IA32 has the similar behavior.

  So this CL will make the implementation of NaN comparision's return value in kX87Float32Min and kX87Float32Max same as Gcc and IA32.

BUG=

Committed: https://crrev.com/a337d159d300274b38506f256c8d9d0d85beb558
Cr-Commit-Position: refs/heads/master@{#32866}

[zhengxing.li, 2015-12-15 07:04:11]

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

[zhengxing.li, 2015-12-15 07:04:11]

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

[chunyang.dai, 2015-12-15 10:04:26]

LGTM.

[Weiliang, 2015-12-15 13:39:31]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-12-15 13:39:32]

lgtm

[commit-bot: I haz the power, 2015-12-15 13:39:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1522333002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1522333002/1

[commit-bot: I haz the power, 2015-12-15 13:59:34]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-15 13:59:54]

Description was changed from

==========
X87: [TurboFan] Change the implementation of Float32's NaN comparision's return
value in kX87Float32Min and kX87Float32Max.

  The CL 32796(https://codereview.chromium.org/1512023002) adds many Float32
comparision test data which including the NaN comparision.

  As there's no Specification for the return value of NaN comparision, Current
x87 will check the Float comparision instruction's first
  operand, if it's NaN, return the second operand. Otherwise, return itself.

  But this conflicts with the Gcc compiler's implementation and cause the
RunFloat32MinP and RunFloat32MaxP tests failed.

  For (a < b) comparision, The Gcc compiler will treat the NaN comparision's
result same as a GT b and return b.
  The minss sse instruction in IA32 has the similar behavior.

  So this CL will make the implementation of NaN comparision's return value in
kX87Float32Min and kX87Float32Max same as Gcc and IA32.

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

to

==========
X87: [TurboFan] Change the implementation of Float32's NaN comparision's return
value in kX87Float32Min and kX87Float32Max.

  The CL 32796(https://codereview.chromium.org/1512023002) adds many Float32
comparision test data which including the NaN comparision.

  As there's no Specification for the return value of NaN comparision, Current
x87 will check the Float comparision instruction's first
  operand, if it's NaN, return the second operand. Otherwise, return itself.

  But this conflicts with the Gcc compiler's implementation and cause the
RunFloat32MinP and RunFloat32MaxP tests failed.

  For (a < b) comparision, The Gcc compiler will treat the NaN comparision's
result same as a GT b and return b.
  The minss sse instruction in IA32 has the similar behavior.

  So this CL will make the implementation of NaN comparision's return value in
kX87Float32Min and kX87Float32Max same as Gcc and IA32.

BUG=

Committed: https://crrev.com/a337d159d300274b38506f256c8d9d0d85beb558
Cr-Commit-Position: refs/heads/master@{#32866}
==========

[commit-bot: I haz the power, 2015-12-15 13:59:55]

Patchset 1 (id:??) landed as
https://crrev.com/a337d159d300274b38506f256c8d9d0d85beb558
Cr-Commit-Position: refs/heads/master@{#32866}