1816883 - JS demo (https://www.fxhash.xyz/generative/18489) appears to spend large amounts of time in non-ion path in lots of functions (time is spent in generators)

Status: NEW

(Core :: JavaScript Engine, task, P3)

Description

[Mayank Bansal]

Go to https://www.fxhash.xyz/generative/18489 (Exact hash used is https://gateway.fxhash2.xyz/ipfs/QmU2rgnYKSHVpnurrGVBAWXbuCHEgSKYR33waLbxpcCPnn/?fxhash=ooTeQ7zc5AdGn2YbJcWLzMbTo5DsEJveorqjygLLiDWRUBzhbXd)

Nightly: https://share.firefox.dev/3Kddo1s

Maybe something worth improving here?

Comment 1

[Mayank Bansal]

Additional profile for 4 different variations : https://share.firefox.dev/3lBgulR
Do the markers suggest lots of bailouts?

Comment 2

[Mayank Bansal]

Another demo made by this person using thi-ng library (https://github.com/thi-ng/fxhash-tpl) appears to have similar profiles with largish time in non-ion path.
https://www.fxhash.xyz/generative/17940 : https://share.firefox.dev/40VyqaU

Comment 3

[Jan de Mooij [:jandem]]

This is spending time in generator code, like this one:

function* tt(...t) {
    const e = t.map(n => n[Symbol.iterator]());
    for (;;) {
        const n = [];
        for (let s of e) {
            let r = s.next();
            if (r.done) return;
            n.push(r.value)
        }
        yield n
    }
}

Comment 4

[Mayank Bansal]

Latest profile: https://share.firefox.dev/44J85hv
from 600ns - > 360ms