Closed Bug 1508547 Opened 2 years ago Closed 2 years ago

Switch Android builds to clang 7 again

Categories

(Firefox Build System :: General, defect)

defect
Not set
normal

Tracking

(firefox65 fixed)

RESOLVED FIXED
mozilla65
Tracking Status
firefox65 --- fixed

People

(Reporter: glandium, Assigned: glandium)

References

Details

Attachments

(2 files)

Bug 1492663 upgraded those builds to clang 7, and bug 1503330 brought them back to clang 6 because of speedometer regressions.

Bisecting llvm trunk between clang 6 and 7 identified the regression as caused by https://github.com/llvm-mirror/llvm/commit/031332e78887f4658e2d7a2f7541827c2ca9baf5 . I filed this as https://bugs.llvm.org/show_bug.cgi?id=39717 but it's entirely possible it won't be changed.

However, we can disable the outliner manually on clang 7, allowing to upgrade again.

No amount of squinting makes me see an actual regression on arm, only aarch64, so we'll upgrade both.
It's enabled by default as of clang 7 with -Oz on aarch64 (that is,
afaict, the only platform where it's enabled), and regresses our
performance on speedometer.
Bug 1492663 upgraded those builds to clang 7, and bug 1503330 brought
them back to clang 6 because of speedometer regressions.

With the previous change, the regression doesn't happen any more,
allowing to upgrade again.

Depends on D12394
Pushed by mh@glandium.org:
https://hg.mozilla.org/integration/autoland/rev/6f3303d415f7
Disable the machine outliner on Android. r=dmajor
https://hg.mozilla.org/integration/autoland/rev/8540104bb0bd
Switch Android builds to clang 7 again. r=dmajor
https://hg.mozilla.org/mozilla-central/rev/6f3303d415f7
https://hg.mozilla.org/mozilla-central/rev/8540104bb0bd
Status: NEW → RESOLVED
Closed: 2 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla65
See Also: → 1520149
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