X87: [ia32] Byte and word memory operands in ia32 cmp/test.

X87: [ia32] Byte and word memory operands in ia32 cmp/test.

  port 3dd3beb06676fe8030d1fef9086cbe63e4a4376d (r35199)

  original commit message:
  Currently, if the size of two cmp or test operands is a byte or a word, we sign-extend or zero-extend each of them into a 32-bit register before doing the comparison, even when the conditions
  for the use of a memory operand are met.

  This CL makes it possible to load only one of them into a register and address the other as a memory operand.

  The tricky bit is that, unlike as in the x64 counterpart http://crrev.com/1780193003, not all registers can be accessed as bytes.

BUG=

Committed: https://crrev.com/39c39b54674561f1935cdd7088c3a880fb582ce4
Cr-Commit-Position: refs/heads/master@{#35508}

[zhengxing.li, 2016-04-15 06:42:10]

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

[zhengxing.li, 2016-04-15 06:42:11]

PTAL, thanks!

[Weiliang, 2016-04-15 06:43:23]

lgtm

[zhengxing.li, 2016-04-15 06:53:35]

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

[commit-bot: I haz the power, 2016-04-15 06:53:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1883373002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1883373002/1

[commit-bot: I haz the power, 2016-04-15 07:14:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-15 07:15:13]

Description was changed from

==========
X87: [ia32] Byte and word memory operands in ia32 cmp/test.

  port 3dd3beb06676fe8030d1fef9086cbe63e4a4376d (r35199)

  original commit message:
  Currently, if the size of two cmp or test operands is a byte or a word, we
sign-extend or zero-extend each of them into a 32-bit register before doing the
comparison, even when the conditions
  for the use of a memory operand are met.

  This CL makes it possible to load only one of them into a register and address
the other as a memory operand.

  The tricky bit is that, unlike as in the x64 counterpart
http://crrev.com/1780193003, not all registers can be accessed as bytes.

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

to

==========
X87: [ia32] Byte and word memory operands in ia32 cmp/test.

  port 3dd3beb06676fe8030d1fef9086cbe63e4a4376d (r35199)

  original commit message:
  Currently, if the size of two cmp or test operands is a byte or a word, we
sign-extend or zero-extend each of them into a 32-bit register before doing the
comparison, even when the conditions
  for the use of a memory operand are met.

  This CL makes it possible to load only one of them into a register and address
the other as a memory operand.

  The tricky bit is that, unlike as in the x64 counterpart
http://crrev.com/1780193003, not all registers can be accessed as bytes.

BUG=

Committed: https://crrev.com/39c39b54674561f1935cdd7088c3a880fb582ce4
Cr-Commit-Position: refs/heads/master@{#35508}
==========

[commit-bot: I haz the power, 2016-04-15 07:15:14]

Patchset 1 (id:??) landed as
https://crrev.com/39c39b54674561f1935cdd7088c3a880fb582ce4
Cr-Commit-Position: refs/heads/master@{#35508}