1913114 - Add pref for lazy tiering that only enables it for GC modules

Status: RESOLVED FIXED

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

Description

[Ryan Hunt [:rhunt]]

Enable the new compile pipeline in Nightly [1]. Also change how the pref works in two ways:

1. Only enable the new mode when the type section has a GC type in it.
2. If we do enable the new mode, we must force tiering to be enabled. This is currently done here [2], but must be done elsewhere to ensure that we only do it for modules that have GC types in it.

[1] https://searchfox.org/mozilla-central/rev/b1b87f95ecea00828298d1b3cd3d8718f9fcc3fc/modules/libpref/init/StaticPrefList.yaml#8255
[2] https://searchfox.org/mozilla-central/rev/b1b87f95ecea00828298d1b3cd3d8718f9fcc3fc/js/src/wasm/WasmCompile.cpp#254-256

Comment 1

[Ryan Hunt [:rhunt]]

Attachment: Bug 1913114 - wasm: Rename lazy tiering prefs and add pref that enables lazy tiering only for wasm-gc. r?yury

• Remove the experimental part of these flags.
• Rename the overall flag to just talk about lazy_tiering.
• Add a lazy_tiering_for_gc which enables this feature only for wasm-gc modules.

Comment 2

[Ryan Hunt [:rhunt]]

Attachment: Bug 1913114 - wasm: Rename tiering aggressiveness pref and use it in our tests. r?yury

Remove the experimental prefix from our tiering level, and use the max in our tests
to ensure we have coverage of tier-ups.

Depends on D225124

Comment 3

[Ryan Hunt [:rhunt]]

Attachment: Bug 1913114 - wasm: Remove 'experimental' from inlining prefs. r?yury

Remove experimental prefix from inlining prefs.
Fix capitalization of callRef to match the instruction.

Depends on D225125

Comment 4

[Ryan Hunt [:rhunt]]

Attachment: Bug 1913114 - wasm: Make heuristics static classes. r?yury

These classes just embed pref values that are already stored
elsewhere. The pref values are just as fast to access as these
heuristic classes so we should just avoid duplicating them.

Depends on D225126

Comment 5

[Ryan Hunt [:rhunt]]

Attachment: Bug 1913114 - wasm: Update tests for new flags, add a sync flag. r?yury

• Add a 'wasm_lazy_tiering_synchronous' flag which avoids a background compile
  to simplify testing.
• Update all tests to use the right prefs.
• Enable some tests that were erroneously disabled still
• Fix an issue with stack comparisons where the 'request-tier-up' stub
  was included.

Depends on D225127

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8f48c0f2c326
wasm: Rename lazy tiering prefs and add pref that enables lazy tiering only for wasm-gc. r=yury
https://hg.mozilla.org/integration/autoland/rev/9d334755b46f
wasm: Rename tiering aggressiveness pref and use it in our tests. r=yury
https://hg.mozilla.org/integration/autoland/rev/fc0435ff8eaa
wasm: Remove 'experimental' from inlining prefs. r=yury
https://hg.mozilla.org/integration/autoland/rev/0d36cfe5c8bf
wasm: Make heuristics static classes. r=yury
https://hg.mozilla.org/integration/autoland/rev/1a822192b8d8
wasm: Update tests for new flags, add a sync flag. r=yury

Comment 7

[Ryan Hunt [:rhunt]]

I used this bug number thinking the patch series would actually enable this feature in nightly. But then realized we need to do some other things first and should land this in the meantime. I'm going to file a new bug for enabling in nightly.

Comment 8

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/8f48c0f2c326
https://hg.mozilla.org/mozilla-central/rev/9d334755b46f
https://hg.mozilla.org/mozilla-central/rev/fc0435ff8eaa
https://hg.mozilla.org/mozilla-central/rev/0d36cfe5c8bf
https://hg.mozilla.org/mozilla-central/rev/1a822192b8d8