1876635 - Don't transpile stubs with popped fuses.

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P3)

Description

[Matthew Gaudet (he/him) [:mgaudet]]

In principle, we could have a monomorphic stub with a guard fuse where the fuse pops before we transpile it; might be nice to detect this and skip transpilation of these stubs.

This is reasonably unlikely, but perhaps still worth it?

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1876635 part 1 - Generate CacheIRReader code for reading op arguments. r?mgaudet!

There are a few places where we manually scan CacheIR ops and read their arguments.
In this case the reader calls have to match the arguments in the YAML file and this
can be error-prone.

The next patch will add another place where we do this so this patch adds code generation
to make this more ergonomic.

For PBL this patch converts a few interesting ops but doesn't convert all of them yet.

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1876635 part 2 - Don't transpile stubs with popped invalidating fuses. r?mgaudet!

Move the dependency tracking from the transpiler to WarpOracle and use a bailout
instead of transpiling the stub if we have a popped fuse. This avoids finishing
an Ion compilation and then immediately throwing away the result when we check
the fuse dependencies at the end.

This likely doesn't matter a lot for the current fuses, but becomes more important with
object property fuses.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/21859e568525
https://hg.mozilla.org/integration/autoland/rev/f8657413e8a3
part 1 - Generate CacheIRReader code for reading op arguments. r=mgaudet
https://github.com/mozilla-firefox/firefox/commit/56357aab846c
https://hg.mozilla.org/integration/autoland/rev/088251a88b60
part 2 - Don't transpile stubs with popped invalidating fuses. r=mgaudet

Comment 4

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/f8657413e8a3
https://hg.mozilla.org/mozilla-central/rev/088251a88b60