759289 - IonMonkey: JM -> Ion calls are slow

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Jan de Mooij [:jandem]]

Consider the following micro-benchmark:
--
function g() {
    while (0) {} // Don't inline g.
}
function f() {
    try {} catch(e) {}; // Force JM.
    for (var i=0; i<10000000; i++) {
        g();
        g();
    }
}
var t = new Date;
f();
print(new Date - t);
--
We fall back to JM for |f| and use IonMonkey to compile |g|. I get the following numbers:

JM     :  131 ms
JM+Ion : 2713 ms
interp : 2724 ms

This is way too slow and affects ss-md5 and probably other benchmarks.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Patch

Applies on top of bug 759409. This uses JM for calls from a JM call IC. It works for the testcase in comment 0 and makes crypto-md5 a bit faster. We'll have to see how this works in practice but I hope this is sufficient.

Comment 2

[Jan de Mooij [:jandem]]

https://hg.mozilla.org/projects/ionmonkey/rev/c4ba8fc5a1d0