1884368 - Retire jit::GetPcScript and PcScriptCache

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, task)

Description

[Jan de Mooij [:jandem]]

GetPcScript used to be very hot and a cache was added for it a long time ago. It no longer is called a lot: the only caller is JSContext::currentScript which also isn't used a lot and I think we can rewrite it to use FrameIter.

This lets us remove the custom JIT frame iteration code and also simplifies bug 1884360 because I was running into an edge case with this that doesn't apply with FrameIter.

The cache is pretty large (73 entries of 24 bytes each) so this is also good for memory usage.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Bug 1884368 - Remove GetPcScript and PcScriptCache. r?iain!

We no longer call GetPcScript or cx->currentScript() on hot paths so we
can now try to use FrameIter instead. This lets us remove the custom frame iteration
code and the fixed-size cache for it.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/de0a8ca2b267
Remove GetPcScript and PcScriptCache. r=iain

Comment 3

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/de0a8ca2b267