X87: [turbofan] Introduce TruncateTaggedToWord32 simplified operator.

X87: [turbofan] Introduce TruncateTaggedToWord32 simplified operator.

  port 0231a7efa2b5ce8108a837284e2f63dccd5dcd09 (r35743)

  original commit message:
  This allows us to get rid of the "push TruncateFloat64ToInt32 into Phi"
  trick that was used in the MachineOperatorReducer to combine the
  ChangeTaggedToFloat64 and TruncateFloat64ToInt32 operations. Instead of
  doing that later, we can just introduce the proper operator during the
  representation selection directly.

  Also separate the TruncateFloat64ToInt32 machine operator, which had two
  different meanings depending on a flag (either JavaScript truncation or
  C++ style round to zero). Now there's a TruncateFloat64ToWord32 which
  represents the JavaScript truncation (implemented via TruncateDoubleToI
  macro + code stub) and the RoundFloat64ToInt32, which implements the C++
  round towards zero operation (in the same style as the other WebAssembly
  driven Round* machine operators).

BUG=

Committed: https://crrev.com/c631277411a75525c2c6167051a1040552c7dd0e
Cr-Commit-Position: refs/heads/master@{#35745}

[zhengxing.li, 2016-04-25 02:15:31]

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

[zhengxing.li, 2016-04-25 02:15:32]

PTAL, thanks!

[Weiliang, 2016-04-25 02:18:53]

lgtm

[zhengxing.li, 2016-04-25 02:32:06]

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

[commit-bot: I haz the power, 2016-04-25 02:32:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1912403002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1912403002/1

[commit-bot: I haz the power, 2016-04-25 02:49:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-25 02:50:15]

Description was changed from

==========
X87: [turbofan] Introduce TruncateTaggedToWord32 simplified operator.

  port 0231a7efa2b5ce8108a837284e2f63dccd5dcd09 (r35743)

  original commit message:
  This allows us to get rid of the "push TruncateFloat64ToInt32 into Phi"
  trick that was used in the MachineOperatorReducer to combine the
  ChangeTaggedToFloat64 and TruncateFloat64ToInt32 operations. Instead of
  doing that later, we can just introduce the proper operator during the
  representation selection directly.

  Also separate the TruncateFloat64ToInt32 machine operator, which had two
  different meanings depending on a flag (either JavaScript truncation or
  C++ style round to zero). Now there's a TruncateFloat64ToWord32 which
  represents the JavaScript truncation (implemented via TruncateDoubleToI
  macro + code stub) and the RoundFloat64ToInt32, which implements the C++
  round towards zero operation (in the same style as the other WebAssembly
  driven Round* machine operators).

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

to

==========
X87: [turbofan] Introduce TruncateTaggedToWord32 simplified operator.

  port 0231a7efa2b5ce8108a837284e2f63dccd5dcd09 (r35743)

  original commit message:
  This allows us to get rid of the "push TruncateFloat64ToInt32 into Phi"
  trick that was used in the MachineOperatorReducer to combine the
  ChangeTaggedToFloat64 and TruncateFloat64ToInt32 operations. Instead of
  doing that later, we can just introduce the proper operator during the
  representation selection directly.

  Also separate the TruncateFloat64ToInt32 machine operator, which had two
  different meanings depending on a flag (either JavaScript truncation or
  C++ style round to zero). Now there's a TruncateFloat64ToWord32 which
  represents the JavaScript truncation (implemented via TruncateDoubleToI
  macro + code stub) and the RoundFloat64ToInt32, which implements the C++
  round towards zero operation (in the same style as the other WebAssembly
  driven Round* machine operators).

BUG=

Committed: https://crrev.com/c631277411a75525c2c6167051a1040552c7dd0e
Cr-Commit-Position: refs/heads/master@{#35745}
==========

[commit-bot: I haz the power, 2016-04-25 02:50:16]

Patchset 1 (id:??) landed as
https://crrev.com/c631277411a75525c2c6167051a1040552c7dd0e
Cr-Commit-Position: refs/heads/master@{#35745}