[turbofan] Introduce NumberFloor simplified operator.

[turbofan] Introduce NumberFloor simplified operator.

The NumberFloor operator matches exactly the semantics of the Math.floor
builtin on Numbers. It uses hardware rounding instructions if available,
but provides a full fallback solution that is compatible with Math.floor.
The lowering is optimizable based on types if needed later, i.e. we
already optimize it for the case that the input is already an Integer
(in the EcmaScript sense, including NaN and -0), but we could add more
optimizations, like combining NumberFloor and NumberDivide in the
future, if necessary.

R=jarin@chromium.org
BUG=v8:2890, v8:4059
LOG=n

Committed: https://crrev.com/43216574ef7969de475fbea0b5276d4a12737686
Cr-Commit-Position: refs/heads/master@{#35090}

[Benedikt Meurer, 2016-03-29 05:58:28]

Hey Jaro,

This removes another machine operator from the JavaScript level (namely
Float64RoundDown) and introduces a proper simplified operator instead. Also
brings the inlined version (for TurboFan) to the same level that we have for
Math.floor (i.e. inlining floor even on ARMv6/ARMv7 where we don't have
Float64RoundDown).
Please take a look.

Thanks,
Benedikt

[Jarin, 2016-03-29 06:07:23]

lgtm. (Although with our effect chain scheduling phase, the simplified lowering
part will have to move elsewhere - either to change lowering or to the
to-be-created effect materialization pass.)

[Benedikt Meurer, 2016-03-29 06:13:28]

On 2016/03/29 06:07:23, Jarin wrote:
> lgtm. (Although with our effect chain scheduling phase, the simplified
lowering
> part will have to move elsewhere - either to change lowering or to the
> to-be-created effect materialization pass.)

Yes, definitely. This will also wire up the control flow immediately then.

[Benedikt Meurer, 2016-03-29 06:13:32]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-03-29 06:13:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1843533003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1843533003/1

[commit-bot: I haz the power, 2016-03-29 06:18:26]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-29 06:20:17]

Description was changed from

==========
[turbofan] Introduce NumberFloor simplified operator.

The NumberFloor operator matches exactly the semantics of the Math.floor
builtin on Numbers. It uses hardware rounding instructions if available,
but provides a full fallback solution that is compatible with Math.floor.
The lowering is optimizable based on types if needed later, i.e. we
already optimize it for the case that the input is already an Integer
(in the EcmaScript sense, including NaN and -0), but we could add more
optimizations, like combining NumberFloor and NumberDivide in the
future, if necessary.

R=jarin@chromium.org
BUG=v8:2890,v8:4059
LOG=n
==========

to

==========
[turbofan] Introduce NumberFloor simplified operator.

The NumberFloor operator matches exactly the semantics of the Math.floor
builtin on Numbers. It uses hardware rounding instructions if available,
but provides a full fallback solution that is compatible with Math.floor.
The lowering is optimizable based on types if needed later, i.e. we
already optimize it for the case that the input is already an Integer
(in the EcmaScript sense, including NaN and -0), but we could add more
optimizations, like combining NumberFloor and NumberDivide in the
future, if necessary.

R=jarin@chromium.org
BUG=v8:2890,v8:4059
LOG=n

Committed: https://crrev.com/43216574ef7969de475fbea0b5276d4a12737686
Cr-Commit-Position: refs/heads/master@{#35090}
==========

[commit-bot: I haz the power, 2016-03-29 06:20:18]

Patchset 1 (id:??) landed as
https://crrev.com/43216574ef7969de475fbea0b5276d4a12737686
Cr-Commit-Position: refs/heads/master@{#35090}