1724201 - Prototype relaxed-SIMD FMA and FMS

Status: RESOLVED FIXED

(Core :: JavaScript: WebAssembly, enhancement, P3)

Description

[Lars T Hansen [:lth]]

See https://github.com/WebAssembly/relaxed-simd/issues/27.

Comment 1

[Lars T Hansen [:lth]]

Attachment: Bug 1724201 - Relaxed SIMD FMA/FMS for x86 and arm64. r?yury

Prototype - only f32x4.fma, only baseline, no wat support. But works
on both x64/x86 and arm64.

Comment 2

[Lars T Hansen [:lth]]

Attachment: Bug 1724201 - Drive-by cleanup, remove some dead code. r?yury

The "experimental" feature is no longer defined and this predicate can
just go away - it should have been removed with the feature.

Comment 3

[Lars T Hansen [:lth]]

Attachment: Bug 1724201 - Repurpose the vector bitselect node as a general ternary op node. r?yury

For FMA and FMS we will need a ternary node, and bitselect already has
the right shape and logic. We just need to rename it and generalize
it slightly with the SIMD op as a parameter, as we have for many other
nodes.

Drive-by fix: bitselect on arm64 does not actually need a temp
register.

Depends on D122079

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/762eaa3d8d19
Drive-by cleanup, remove some dead code. r=yury
https://hg.mozilla.org/integration/autoland/rev/4736a84c2dbb
Repurpose the vector bitselect node as a general ternary op node. r=yury
https://hg.mozilla.org/integration/autoland/rev/ba0bb80adf91
Relaxed SIMD FMA/FMS for x86 and arm64.  r=yury

Comment 5

[Atila Butkovits]

Backed out for causing bustages on LIR-shared.h.

Backout link: https://hg.mozilla.org/integration/autoland/rev/f80bd6c1f30e9afcda6b13e79308193a368935fb

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=ba0bb80adf91cf1370eb99596e2a2887f4d734b9&searchStr=build&selectedTaskRun=IkxOMNlbTgu-comhJ1D5gg.0

Failure log: https://treeherder.mozilla.org/logviewer?job_id=348324030&repo=autoland&lineNumber=37791

Comment 6

[Lars T Hansen [:lth]]

That's extremely weird, because it builds fine locally. Treeherder shows that the non-unified build works, so this may be some badness with header files. Investigating...

Comment 7

[Lars T Hansen [:lth]]

YAYO (Yet Another YAML Oversight). Probably one more argument why config phrases that drive codegen should be embedded in the code, not in a separate file.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cbd6016b8501
Drive-by cleanup, remove some dead code. r=yury
https://hg.mozilla.org/integration/autoland/rev/95c7858db7b5
Repurpose the vector bitselect node as a general ternary op node. r=yury
https://hg.mozilla.org/integration/autoland/rev/3cf25ec47e91
Relaxed SIMD FMA/FMS for x86 and arm64.  r=yury

Comment 9

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/cbd6016b8501
https://hg.mozilla.org/mozilla-central/rev/95c7858db7b5
https://hg.mozilla.org/mozilla-central/rev/3cf25ec47e91