[turbofan] Extend optimization of flooring integer division.

[turbofan] Extend optimization of flooring integer division.

So far we only recognize the special

  NumberFloor(NumberDivide(lhs, rhs))

subgraph when both lhs and rhs are in the Unsigned32 range, and the
result is a PlainNumber. Extend this pattern matching to also cover

  NumberFloor(SpeculativeNumberDivide(lhs, rhs))

and to replace the NumberFloor with NumberToInt32 truncation if the
lhs value is in Signed32 range and the rhs is in Unsigned32 range.

R=jarin@chromium.org
BUG=v8:5267
Review-Url: https://codereview.chromium.org/2739573004
Cr-Commit-Position: refs/heads/master@{#43642}
Committed: https://chromium.googlesource.com/v8/v8/+/f0e7a3174e4470d04c923db577c6b238b2d20f09

[Benedikt Meurer, 2017-03-07 13:34:37]

The CQ bit was checked by bmeurer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-07 13:34:43]

Dry run: 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, 2017-03-07 13:58:33]

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

[commit-bot: I haz the power, 2017-03-07 13:58:34]

Dry run: This issue passed the CQ dry run.

[Jarin, 2017-03-07 14:00:27]

https://codereview.chromium.org/2739573004/diff/1/src/compiler/operation-type...
File src/compiler/operation-typer.cc (right):

https://codereview.chromium.org/2739573004/diff/1/src/compiler/operation-type...
src/compiler/operation-typer.cc:641: (rhs->Min() == -V8_INFINITY || rhs->Max()
== +V8_INFINITY);
As discussed offline, this is not correct because of underflow. It should be
fine for lhs integer (i.e., if lhs is not integer the result may be -0).

[Benedikt Meurer, 2017-03-07 14:12:11]

The CQ bit was checked by bmeurer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-07 14:12:22]

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

[Benedikt Meurer, 2017-03-07 14:16:24]

The CQ bit was checked by bmeurer@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-07 14:16:31]

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

[Benedikt Meurer, 2017-03-07 14:16:39]

https://codereview.chromium.org/2739573004/diff/1/src/compiler/operation-type...
File src/compiler/operation-typer.cc (right):

https://codereview.chromium.org/2739573004/diff/1/src/compiler/operation-type...
src/compiler/operation-typer.cc:641: (rhs->Min() == -V8_INFINITY || rhs->Max()
== +V8_INFINITY);
On 2017/03/07 14:00:27, Jarin wrote:
> As discussed offline, this is not correct because of underflow. It should be
> fine for lhs integer (i.e., if lhs is not integer the result may be -0).

Done.

[Jarin, 2017-03-07 14:20:01]

lgtm

https://codereview.chromium.org/2739573004/diff/20001/src/compiler/operation-...
File src/compiler/operation-typer.cc (right):

https://codereview.chromium.org/2739573004/diff/20001/src/compiler/operation-...
src/compiler/operation-typer.cc:639: !lhs->Is(cache_.kInteger) ||
!rhs->Is(cache_.kIntegerOrMinusZero) ||
I believe the rhs check here is not necessary, let's remove it.

[Benedikt Meurer, 2017-03-07 14:20:35]

The CQ bit was unchecked by bmeurer@chromium.org

[Benedikt Meurer, 2017-03-07 14:20:45]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-03-07 14:20:56]

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, 2017-03-07 14:46:11]

CQ is committing da patch.

Bot data: {"patchset_id": 40001, "attempt_start_ts": 1488896445396030,
"parent_rev": "f489f7ab44eb4e602396d4b6e46f99c024ac3fed", "commit_rev":
"f0e7a3174e4470d04c923db577c6b238b2d20f09"}

[commit-bot: I haz the power, 2017-03-07 14:46:16]

Description was changed from

==========
[turbofan] Extend optimization of flooring integer division.

So far we only recognize the special

  NumberFloor(NumberDivide(lhs, rhs))

subgraph when both lhs and rhs are in the Unsigned32 range, and the
result is a PlainNumber. Extend this pattern matching to also cover

  NumberFloor(SpeculativeNumberDivide(lhs, rhs))

and to replace the NumberFloor with NumberToInt32 truncation if the
lhs value is in Signed32 range and the rhs is in Unsigned32 range.

R=jarin@chromium.org
BUG=v8:5267
==========

to

==========
[turbofan] Extend optimization of flooring integer division.

So far we only recognize the special

  NumberFloor(NumberDivide(lhs, rhs))

subgraph when both lhs and rhs are in the Unsigned32 range, and the
result is a PlainNumber. Extend this pattern matching to also cover

  NumberFloor(SpeculativeNumberDivide(lhs, rhs))

and to replace the NumberFloor with NumberToInt32 truncation if the
lhs value is in Signed32 range and the rhs is in Unsigned32 range.

R=jarin@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2739573004
Cr-Commit-Position: refs/heads/master@{#43642}
Committed:
https://chromium.googlesource.com/v8/v8/+/f0e7a3174e4470d04c923db577c6b238b2d...
==========

[commit-bot: I haz the power, 2017-03-07 14:46:17]

Committed patchset #3 (id:40001) as
https://chromium.googlesource.com/v8/v8/+/f0e7a3174e4470d04c923db577c6b238b2d...