1761850 - Inconsistent results (f64.abs or f64.lt) on Intel vs M1 Mac

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, defect, P1)

Description

[Andrew Swan [:aswan]]

Attachment: wasm-opt.html

See attached test case -- the page displays "OK" on an Intel-based Mac and "Error: NaN" on an M1. Also running on M1 and setting a breakpoint in the wasm and then stepping through causes the page to display "OK", which suggests a bug in native code generation on M1?
All tests were with Firefox 98.0.2.

Comment 1

[Yury Delendik (:yury)]

Attachment: Bug 1761850 - Fix wasm select on ARM64. r?jseward

JSOpToCondition is applicable only to integer types. JSOpToDoubleCondition and
ConditionFromDoubleCondition sequence has to be used for float types.

Comment 2

[Lars T Hansen [:lth]]

I assume FF98, FF99, and even FF91ESR are affected; please investigate. Uplifts would be welcome for at least 91 and 99.

Comment 3

[Yury Delendik (:yury)]

Looks like bug 1710024 is prerequisite for this bug, and it is present in esr91. I will check if the patch lands cleanly with all suggested versions.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/27d2bf526ea8
Fix wasm select on ARM64. r=jseward

Comment 5

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/27d2bf526ea8

Comment 6

[Yury Delendik (:yury)]

Comment on attachment 9269769 [details]
Bug 1761850 - Fix wasm select on ARM64. r?jseward

Beta/Release Uplift Approval Request

• User impact if declined: Some wasm application may not work properly on Aarch64 or Apple M1 hardware.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): The changes only affect the code that produces the error, limited to the affected platform, and tests are provided.
• String changes made/needed:

ESR Uplift Approval Request

• If this is not a sec:{high,crit} bug, please state case for ESR consideration: Having the proper implementation of Wasm SIMD is somewhat important -- new application that use this technology are appearing on the market at this moment and could cause issues for ESRs.
• User impact if declined: Some wasm application may not work properly on Aarch64 or Apple M1 hardware.
• Fix Landed on Version: 100
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): The changes only affect the code that produces the error, limited to the affected platform, and tests are provided.

Comment 7

[Donal Meehan [:dmeehan]]

Comment on attachment 9269769 [details]
Bug 1761850 - Fix wasm select on ARM64. r?jseward

This will be carried from Central to Beta with Merge Day

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9269769 [details]
Bug 1761850 - Fix wasm select on ARM64. r?jseward

Important ARM64 WASM correctness fix with tests. Approved for 91.9esr.

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-esr91/rev/94e42a10297a

Comment 10

[Donal Meehan [:dmeehan]]

Comment on attachment 9269769 [details]
Bug 1761850 - Fix wasm select on ARM64. r?jseward

Approved for 99.0.1.

Comment 11

[Donal Meehan [:dmeehan]]

https://hg.mozilla.org/releases/mozilla-release/rev/f012d82ef4b8