1837683 - (wasm-branch-hinting) Implement the branch-hinting proposal

Status: RESOLVED FIXED

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

Description

[Ryan Hunt [:rhunt]]

The branch-hinting proposal adds a new custom section to store 'code hints'. Code hints allow compilers to annotate instructions with non-semantic information like 'branch likely to be taken'.

We currently don't have any way of using this information in baseline or Ion, but we could add support.

Comment 1

[Julien Pages [:jpages]]

Attachment: Bug 1837683 - wasm: Parsing of the custom branch hinting section.

Comment 2

[Julien Pages [:jpages]]

Attachment: Bug 1837683 - wasm: First implementation of the branch hinting proposal.

Depends on D192986

Comment 3

[Julien Pages [:jpages]]

Patch for encoding/parsing of branch hints in wast:

https://github.com/bytecodealliance/wasm-tools/pull/1394

Comment 4

[Julien Pages [:jpages]]

Attachment: Bug 1837683 - Update wast, wasm-smith and wasm-encoder.

Comment 5

[Julien Pages [:jpages]]

Attachment: Bug 1837683 - wasm: test case for branch hinting.

Depends on D192987

Comment 6

[Julien Pages [:jpages]]

As a reference, here is the document describing this proposal: https://github.com/WebAssembly/branch-hinting/blob/main/proposals/branch-hinting/Overview.md

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/11e1e0ddbd25
wasm: Parsing of the custom branch hinting section. r=rhunt
https://hg.mozilla.org/integration/autoland/rev/7ea9f1c02ee7
wasm: First implementation of the branch hinting proposal. r=rhunt
https://hg.mozilla.org/integration/autoland/rev/48374469e36a
wasm: test case for branch hinting. r=rhunt

Comment 8

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/11e1e0ddbd25
https://hg.mozilla.org/mozilla-central/rev/7ea9f1c02ee7
https://hg.mozilla.org/mozilla-central/rev/48374469e36a