636219 - JM: Interpreter's useMethodJIT flag needs to be reset when entering a new function

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Bug 631951 introduced the useMethodJIT flag to the interpreter, which determines whether we should try to methodjit a function after enough back edges have been taken. This flag gets disabled if we try to methodjit and abort (due to code not handled by the mjit).

The problem is that this doesn't account for the fact that a single Interpret invocation can enter and exit functions many JS functions. We should be resetting the useMethodJIT flag each time. Otherwise we won't JIT enough stuff. This is causing a slowdown in bug 636096.

Comment 1

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: patch

This patch adds a RESET_USE_METHODJIT macro that resets the flag. This macro gets called when we enter Interpret and any time we increment or decrement inlineCallCount.

Comment 2

[Mike Shaver (:shaver emeritus)]

Comment on attachment 514554 [details] [diff] [review]
patch

a=shaver

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

http://hg.mozilla.org/tracemonkey/rev/d41da4931c34

Comment 4

[Robert Sayre]

http://hg.mozilla.org/mozilla-central/rev/d41da4931c34