[turbofan] Remove typeof optimization from typed lowering.

[turbofan] Remove typeof optimization from typed lowering.

Now that Ignition has the dedicated TestTypeOf operator, there's not
really a point in doing the typeof with abstract/strict equal combining
in TurboFan anymore. In fact it's counter-productive to do so, as it
might try to cover typeof comparisons in cases where it's better to just
compute the typeof once, i.e.:

  let x = typeof a, y = typeof b;
  if (x === y) {
    if (x === 'string') {
      ...
    }
  }

Here we would combine the second comparison into an ObjectIsString, and
still compute the typeof a.

R=jarin@chromium.org
BUG=v8:5267
Review-Url: https://codereview.chromium.org/2780953003
Cr-Commit-Position: refs/heads/master@{#44220}
Committed: https://chromium.googlesource.com/v8/v8/+/0554e36be0a5406627370606b9791f1f9ec7abd3

[Benedikt Meurer, 2017-03-29 08:02:30]

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

[commit-bot: I haz the power, 2017-03-29 08:02:41]

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, 2017-03-29 08:24:30]

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

[commit-bot: I haz the power, 2017-03-29 08:24:31]

Dry run: This issue passed the CQ dry run.

[Jarin, 2017-03-29 09:00:29]

lgtm

[Benedikt Meurer, 2017-03-29 09:03:55]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-03-29 09:04:02]

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, 2017-03-29 09:07:30]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490778235414980, "parent_rev":
"ab4c91904d3507f2ad1247a42b67eb1630fbb72f", "commit_rev":
"0554e36be0a5406627370606b9791f1f9ec7abd3"}

[commit-bot: I haz the power, 2017-03-29 09:07:35]

Description was changed from

==========
[turbofan] Remove typeof optimization from typed lowering.

Now that Ignition has the dedicated TestTypeOf operator, there's not
really a point in doing the typeof with abstract/strict equal combining
in TurboFan anymore. In fact it's counter-productive to do so, as it
might try to cover typeof comparisons in cases where it's better to just
compute the typeof once, i.e.:

  let x = typeof a, y = typeof b;
  if (x === y) {
    if (x === 'string') {
      ...
    }
  }

Here we would combine the second comparison into an ObjectIsString, and
still compute the typeof a.

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

to

==========
[turbofan] Remove typeof optimization from typed lowering.

Now that Ignition has the dedicated TestTypeOf operator, there's not
really a point in doing the typeof with abstract/strict equal combining
in TurboFan anymore. In fact it's counter-productive to do so, as it
might try to cover typeof comparisons in cases where it's better to just
compute the typeof once, i.e.:

  let x = typeof a, y = typeof b;
  if (x === y) {
    if (x === 'string') {
      ...
    }
  }

Here we would combine the second comparison into an ObjectIsString, and
still compute the typeof a.

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

Review-Url: https://codereview.chromium.org/2780953003
Cr-Commit-Position: refs/heads/master@{#44220}
Committed:
https://chromium.googlesource.com/v8/v8/+/0554e36be0a5406627370606b9791f1f9ec...
==========

[commit-bot: I haz the power, 2017-03-29 09:07:35]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/0554e36be0a5406627370606b9791f1f9ec...