650071 - Optimize |arguments| usage better

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[David Mandelin [:dmandelin]]

From bug 642001 comment 5, we need to make this benchmark faster. One way would be to improve the arguments escape analysis we have. I think v8 might be fast on this mostly because they can allocate |arguments| objects very fast, so this might alternatively be done by waiting for generational GC and then doing arguments a bit differently.

    function sc_Pair() {
    }

    function sc_list() {
        var res = null;
        var a = arguments;
        for (var i = a.length-1; i >= 0; i--)
            res = sc_Pair(a[i], res);
        return res;
    }

    var t0 = new Date;
    for (var i = 0; i < 1000000; ++i)
        sc_list(1, 2, 3);
    print(new Date - t0);

Comment 1

[Tom S [:evilpie]]

Maybe have a look how much Bug 616744 would help here.

Comment 2

[Tom S [:evilpie]]

Fixed by TI, SSA arguments optimization.