1166184 - Eliminate SetObjectElement calls on Treeherder

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine: JIT, defect)

Description

[Jan de Mooij [:jandem]]

I was profiling a Treeherder page load yesterday and noticed we spend about 8% in SetObjectElement. Angular has an apparently very hot "extend" function, that does:

    for (var keys = Object.keys(obj), j = 0, jj = keys.length; jj > j; j++) {
        var key = keys[j];
        dst[key] = obj[key]
    }

The first problem is that IonBuilder doesn't use a SETELEM cache if the access isn't dense or typed array; we probably need a new SetElement stub to handle this case.

Comment 1

[Jan de Mooij [:jandem]]

The issue in comment 0 was fixed by bug 1214126, I'll just close this.