513616 - [meta] nanojit: clean up register allocator

Status: RESOLVED FIXED

(Core Graveyard :: Nanojit, defect)

Description

[Nicholas Nethercote [:njn]]

Nanojit's register allocator is poorly documented, hard to understand, and contains at least one subtle-but-pervasive bug.

I plan to improve this situation via a series of small patches that refactor code, improve documentation, and fix bugs.  (In fact, I've already started doing this.)  I plan to do it that way because I don't have a clear end goal in my mind, but I do see various small improvements to make, which well then enable further small improvements, etc.

Lest this seems like needless pedantry and tidy-ups:  making these changes will also improve my understanding of the register allocator in general, which will then help me make performance improvements to it later on.  (The code improvements will also make it easier for others to make performance improvements.)

This is a meta bug for tracking these improvements.

Comment 1

[Andreas Gal :gal]

bug 514374 introduces an ugly use of allocator.free (~allocator.free). It should be cleaned up as part of this bug.

Comment 2

[Nicholas Nethercote [:njn]]

(In reply to comment #1)
> bug 514374 introduces an ugly use of allocator.free (~allocator.free). It
> should be cleaned up as part of this bug.

I think we already had one occurrence of ~allocator.free anyway.

Also, I don't think bug 514374 should be blocked by this meta-bug, as it will prevent bug 514374 from being closed until this bug is closed.  Filing a new bug for removing ~allocator.free and making it block this bug would be better.

Comment 3

[Nicholas Nethercote [:njn]]

(In reply to comment #2)
> 
> Also, I don't think bug 514374 should be blocked by this meta-bug, as it will
> prevent bug 514374 from being closed until this bug is closed.  Filing a new
> bug for removing ~allocator.free and making it block this bug would be better.

Done: bug 514551 created, and the 514374 block has been removed.

Comment 4

[Nicholas Nethercote [:njn]]

I'm gonna close this bug, it's served its purpose even though there are a couple of blocking bugs still open.