1666867 - Switch default spidermonkey compiler from gcc to clang

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P3)

Description

[Steve Fink [:sfink] [:s:]]

The spidermonkey builds should normally match the browser.

https://treeherder.mozilla.org/#/jobs?repo=try&revision=5c4757c19782e5286013e9e40b32eca216f9ec26

Comment 1

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1666867 - Switch default spidermonkey compiler from gcc to clang

Comment 2

[Steve Fink [:sfink] [:s:]]

One issue: /builds/worker/checkouts/gecko/js/src/jit/arm64/vixl/Logic-vixl.cpp:3607:16: error: implicit conversion from 'const int64_t' (aka 'const long') to 'double' changes value from 9223372036854775807 to 9223372036854775808 [-Werror,-Wimplicit-const-int-float-conversion]

I don't know what the intended behavior is. So I'll punt it to someone.

Comment 3

[Steve Fink [:sfink] [:s:]]

Thus quoth sstangl: "that code is intended to saturate the integer value to the maximum if it's not representable directly. The value as-is doesn't exist in f64 range, but it compares therefore against the lowest value that does. So that's correct as-is and saturates appropriately."

Also: "You could add a new constant that's the lowest f64 above or equal to i64_max"

Comment 4

[Steve Fink [:sfink] [:s:]]

I was a little confused, because I made a sample program and could not reproduce the warning. It looks like it's a difference between clang 9 and clang 11 (we must've upgraded recently? I know I've run mach bootstrap pretty recently, yet still had clang 9).

I'll upload a patch to fix it as soon as I verify it locally.

Comment 5

[Steve Fink [:sfink] [:s:]]

Attachment: Bug 1666867 - Fix warning with imprecise integer conversion to double on clang 11.

Comment 6

[Lars T Hansen [:lth]]

Yes, I've seen that warning too.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0bd465435b9f
Fix warning with imprecise integer conversion to double on clang 11. r=lth

Comment 8

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/0bd465435b9f

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/de9d50aea943
Switch default spidermonkey compiler from gcc to clang r=jandem

Comment 10

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/mozilla-central/rev/de9d50aea943