1638586 - Optimize MathAbs in CacheIR and Warp

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement)

Description

[Tom S [:evilpie]]

Math.abs dominates the run-time of kraken-gaussian-blur.

Comment 1

[Tom S [:evilpie]]

Attachment: Bug 1638586 - Cleanup and share more code for double abs in Ion. r?jandem

Comment 2

[Tom S [:evilpie]]

Attachment: Bug 1638586 - Introduce and use branchNeg32. r?jandem

Depends on D75689

Comment 3

[Tom S [:evilpie]]

Attachment: Bug 1638586 - Support double and int32 Math.abs in CacheIR. r?iain

Depends on D75690

Comment 4

[Tom S [:evilpie]]

Attachment: Bug 1638586 - Transpile Math.abs in Warp. r?iain

Depends on D75691

Comment 5

[Tom S [:evilpie]]

The type monitoring implications around INT32_MIN and so are a bit dangerous. Maybe we should just always monitor? I might also have made some silly mistake on non-x64. Try: https://hg.mozilla.org/try/rev/70708c2b7c6c2c6ca5df6595558d9c14c6e980df

Comment 6

[Jan de Mooij [:jandem]]

(In reply to Tom Schuster [:evilpie] from comment #5)

The type monitoring implications around INT32_MIN and so are a bit dangerous. Maybe we should just always monitor?

The C++ code does a double Abs and then uses setNumber, so it's possible to have a double like 3.0 where the C++ code would return an int32 and the IC a double... Monitoring might make sense because of that - it's still much faster than what we're doing now and type monitoring is hopefully temporary.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c30f74744dda
Cleanup and share more code for double abs in Ion. r=jandem
https://hg.mozilla.org/integration/autoland/rev/8a549beacd6b
Introduce and use branchNeg32. r=jandem
https://hg.mozilla.org/integration/autoland/rev/6e4a013df094
Support double and int32 Math.abs in CacheIR. r=iain
https://hg.mozilla.org/integration/autoland/rev/51588346ff98
Transpile Math.abs in Warp. r=iain

Comment 8

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/c30f74744dda
https://hg.mozilla.org/mozilla-central/rev/8a549beacd6b
https://hg.mozilla.org/mozilla-central/rev/6e4a013df094
https://hg.mozilla.org/mozilla-central/rev/51588346ff98