1976218 - Use InlineSet for CompilationDependencyTracker

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task, P1)

Description

[Jan de Mooij [:jandem]]

We currently use a Vector and we assert we don't add more than 32 dependencies to it, but that will no longer be guaranteed when we have more dynamic fuses. We can change this code to use an InlineSet to still optimize for a very small number of fuses (still the common case).

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1976218 part 1 - Use TempAllocator instead of malloc for compilation dependencies. r?mgaudet!

This works because the LifoAlloc is freed at the end of the compilation task,
after the compilation dependency tracker is reset().

This is more efficient when we can add more than a few dependencies (especially when
this happens on the main thread), but it's also required for the next patch because
InlineSet currently doesn't like when the hash policy's Lookup and Key types are
different (we'd want Key to be a UniquePtr and Lookup to be a raw pointer or
reference).

Comment 2

[Jan de Mooij [:jandem]]

Attachment: Bug 1976218 part 2 - Use InlineSet for CompilationDependencyTracker. r?mgaudet!

Changing the Vector to an InlineSet allows us to add more dynamic dependencies
later, while still optimizing for the common very-few-dependencies case.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/a0b361f694e7
https://hg.mozilla.org/integration/autoland/rev/39403c6bf7ea
part 1 - Use TempAllocator instead of malloc for compilation dependencies. r=mgaudet
https://github.com/mozilla-firefox/firefox/commit/06b51c8d1f70
https://hg.mozilla.org/integration/autoland/rev/cbd3b1d025d3
part 2 - Use InlineSet for CompilationDependencyTracker. r=mgaudet

Comment 4

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/39403c6bf7ea
https://hg.mozilla.org/mozilla-central/rev/cbd3b1d025d3