558227 - JM: PIC for SETPROP

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[David Mandelin [:dmandelin]]

Mostly the inverse of getprop. The interpreter has an optimization for code like:

  for (...) {
    o = {}
    o.a = 8;
    o.b = 9;  // we set to the same slot, and end up with same shape every time
  }

where it holds the sprop for the new property in the prop cache entry, so it can try to increase the slot count in the object and update the scope without doing a full putProperty. That's way too complicated to do outside a stub call, but it probably still makes sense to do (inside a stub call). Testing will tell.

Comment 1

[David Mandelin [:dmandelin]]

Attachment: WIP

Comment 2

[David Mandelin [:dmandelin]]

Pushed the basic PIC. Now it needs perf testing.

Comment 3

[David Mandelin [:dmandelin]]

OK, done. Any further work in this area can be in new bugs.