599273 - JM: 280slides does not work with method jit

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Michael Monreal [:micmon]]

http://280slides.com/Editor/ gets stuck loading at 87% with javascript.options.methodjit.content = true

The following error shows up in the console:
---
Error: _CPRunLoopPerformPool is undefined
<unCork> Source File: http://280slides.com/Editor/1224293852/Frameworks/Objective-J/Objective-J.js
 Line: 1664
---

Works without method jit and works on chrome.

Comment 1

[(mostly gone) XtC4UaLL [:xtc4uall]]

Also reproduceable using Mozilla/5.0 (Windows NT 5.1; rv:2.0b7pre) Gecko/20100920 Firefox/4.0b7pre (Built from http://hg.mozilla.org/tracemonkey/rev/f1b428337950).

Comment 2

[David Anderson [:dvander] - inactive, e-mail if emergency]

I can reproduce this. Investigating.

Comment 3

[David Anderson [:dvander] - inactive, e-mail if emergency]

bug 593556 fixes the initial error, but now I get

JavaScript error: http://280slides.com/Editor/1224293852/Frameworks/Objective-J/Objective-J.js, line 1773: _isPerformingSelectors is not defined

Comment 5

[David Anderson [:dvander] - inactive, e-mail if emergency]

--disable-polyic fixes this. disabling BIND, NAME, and GETELEM PICs doesn't. So the bug is probably in GETPROP or SETPROP.

Comment 6

[David Anderson [:dvander] - inactive, e-mail if emergency]

Okay, the bug stops occurring if I disable PICs for JSOP_GETPROP or JSOP_GETLOCALPROP.

Comment 7

[David Anderson [:dvander] - inactive, e-mail if emergency]

Phew. 280slides uses Objective-J which is really hairy to debug. |with|, deep closures, megamorphism, |new Function()|, oh my.

I narrowed this down to bytecode position 72 in this snippet:

00070:  96  this
00071:  96  this
00072:  96  getprop "method_store"
00075:  96  getprop "prototype"
00078:  96  setprop "method_dtable"
00081:  96  pop

shape->isMethod() is true, but we never call methodReadBarrier(). I've filed bug 600424. We'll see where 280slides is after that's fixed.

Comment 8

[David Anderson [:dvander] - inactive, e-mail if emergency]

Okay, 280slides works after those two bugs are fixed.