[turbofan] Compute more precise type for ObjectIsSmi if possible.

[turbofan] Compute more precise type for ObjectIsSmi if possible.

The typer can infer true/false for ObjectIsSmi if the argument has a
fixed/known representation (i.e. is either known to be smi or heap
object).

R=jarin@chromium.org

Committed: https://crrev.com/66ca9c83814bff53b77dde0b98cb125add9d10e9
Cr-Commit-Position: refs/heads/master@{#31354}

[Benedikt Meurer, 2015-10-19 06:15:55]

Hey Jaro,

Easy change for the Typer to eliminate a bunch of smi checks.
Please take a look.

Thanks,
Benedikt

[Jarin, 2015-10-19 07:23:22]

lgtm

https://codereview.chromium.org/1412673003/diff/20001/src/compiler/typer.cc
File src/compiler/typer.cc (right):

https://codereview.chromium.org/1412673003/diff/20001/src/compiler/typer.cc#n...
src/compiler/typer.cc:1662: if (arg->Is(Type::None())) return arg;
I think it would be better to say "return Type::None()" here.

[Benedikt Meurer, 2015-10-19 07:25:25]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-10-19 07:25:25]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/1412673003/#ps40001
(title: "Address Jaro's comment.")

[commit-bot: I haz the power, 2015-10-19 07:25:26]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1412673003/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1412673003/40001

[Benedikt Meurer, 2015-10-19 07:25:44]

https://codereview.chromium.org/1412673003/diff/20001/src/compiler/typer.cc
File src/compiler/typer.cc (right):

https://codereview.chromium.org/1412673003/diff/20001/src/compiler/typer.cc#n...
src/compiler/typer.cc:1662: if (arg->Is(Type::None())) return arg;
On 2015/10/19 07:23:22, Jarin wrote:
> I think it would be better to say "return Type::None()" here.

Done.

[commit-bot: I haz the power, 2015-10-19 07:47:21]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-10-19 07:47:44]

Patchset 3 (id:??) landed as
https://crrev.com/66ca9c83814bff53b77dde0b98cb125add9d10e9
Cr-Commit-Position: refs/heads/master@{#31354}