Performance regression between v1.1.4 and v1.1.5+

[attractivechaos]

What version of Bun is running?

1.2.2+c1708ea6a

What platform is your computer?

Darwin 24.2.0 arm64 arm

What steps can reproduce the bug?

wget https://raw.githubusercontent.com/attractivechaos/plb2/refs/heads/master/src/javascript/matmul.js
time bun matmul.js

The result is correct for all versions but newer versions are much slower. On my Mac M1:

1.8 sec for bun-1.1.4
4.5 sec for bun-1.1.5 and bun-1.2.2
3.1 sec for node-18.20.3 and deno-1.39.1

What is the expected behavior?

This script should take 1.8 seconds to run.

What do you see instead?

It now takes 4.5 sec, slower than node/deno.

Additional information

No response

[Jarred-Sumner]

I think this is a JavaScriptCore bug.