[pypy-dev] Rough draft of x86-64 JIT backend GSoC proposal

[Gabriel Lavoie]

Starting from May 1 I leave my current job and I'm returning full time at
university to work on my MSc project with PyPy. A FreeBSD 7.3 x86_64
buildbot from me is already available for the PyPy project. I also work
under MacOS X (Snow Leopard) for my MSc project. I could probably help you
for the particularities of these two platforms.

Keep me updated!

Gabriel Lavoie

2010/3/30 Maciej Fijalkowski <fijall at gmail.com>

> On Mon, Mar 29, 2010 at 9:12 PM, Jason Creighton <jcreigh at gmail.com>
> wrote:
> > Hi Guys,
> >
> > I am a student planning on applying to GSoC to create an x86-64 backend
> > for the JIT. I have a (very) rough draft of my proposal, and I was
> > hoping to get some feedback on it.
> >
> > Specifically, I'm wondering about operating system support. I've written
> > the proposal as if I would support Linux/Mac OS X/Windows.
>
> That would be great to have, but I would be happy enough to have it on
> linux. Let's say that if pypy continues to work on os x and windows
> you'll fix remaining 64bit JIT bugs.
>
> >
> > I would be developing on Linux, so I think we can assume that would be
> > fairly well supported, but obviously I would like it to work on Mac OS X
> > and Windows as well. (I'm not sure if I would have the time/motivation
> > to care about obscure BSDs). OTOH, if there are already a lot of
> > outstanding issues on one of those platforms, I don't know that I would
> > be able to get it working. So what do you think would be a reasonable
> > goal here?
>
> It's not like pypy works on anything else than linux os x and windows.
>
> >
> > Secondly, my timeline is pretty vague. The PSF proposal template
> > recommends a week-by-week timeline, but honestly, I'm not sure how the
> > time usage would break down. Any comments on that would be greatly
> > appreciated.
>
> I think week based planning is ridiculous. That may be done for some
> simpler stuff, but not for this. I would say have some milestones, but
> avoid precise timing.
>
> >
> > Here's the draft:
> >
> > === Proposal ===
> >
> > The PyPy JIT, which has shown substantial performance improvements over
> > CPython, often several times faster, does not currently support the
> > x86-64 instruction set, making it impractical to use on 64-bit x86
> > systems.
>
> and over unladen swallow.
>
> >
> > My proposal is to extend the existing x86 JIT backend to support x86-64
> > as well.
> >
> > === Deliverables ===
> >
> > Stable, tested 64-bit JIT for PyPy on Linux, Mac OS X and Windows merged
> > into PyPy trunk.
> >
> > === Implementation plan ===
> >
> > This is not a research proposal. The goal is simply to have a PyPy JIT
> > that works out of the box on 64-bit CPUs, implemented as conservatively
> > as possible.
> >
> > As such, I will attempt to reuse as much of the existing x86 backend
> > that I can. In fact, the architectural similarities between x86 and
> > x86-64 are large enough that I hope to implement a unified x86/x86-64
> > backend with the majority of the code working for either platform.
> >
> > There is an existing branch that, while very incomplete, has the
> > beginnings of a unified x86/x86-64 instruction encoding module. I intend
> > to use that branch as a starting point.
> >
> > Rough outline:
> >
> > 1. Take the existing "remove-ri386-multimethod-2" branch and use it as a
> > basis for instruction encoding.
> >
> > 2. Port the existing 32-bit backend to use the new instruction encoding
> > scheme.
> >
> > 3. Add 64-bit support to the backend,
> >         A) Modify register allocator to use new general purpose and
> >         floating point registers.
> >         B) Port "ResOperation" operations to 64-bit
> >         C) Port guard failure handling to 64-bit
> >
> > 4. Test 64-bit on Mac OS X and Windows and fix inevitable issues.
>
> There is also part about asmgcc.
>
> >
> > === About Me ===
> >
> > I am a first-year Computer Science student at Flathead Valley Community
> > College planning to transfer to Montana State University.
> >
> > I have several years of professional development experience. I am
> > comfortable programming in Python, C and x86 assembly.
> >
> > Starting May 17th, I will be able to commit 40 hours/week to the project
> > until the end of August. I may travel for a few weeks at some point in
> > the summer, but I will have a laptop with me with the expectation of
> > continuing full-time work.
> >
> > === Contact information ===
> >
> > Email: jcreigh at gmail.com
> > IRC:   "jcreigh" on Freenode
> > Phone: (will be given on request, but not preferred)
> > _______________________________________________
> > pypy-dev at codespeak.net
> > http://codespeak.net/mailman/listinfo/pypy-dev
> >
>
> Proposal is rather short, but I don't see how to expand it. You might
> want to add that in case you finish this stuff earlier you would do
> this and that (or just general JIT work or not do anything and drink
> beer).
> _______________________________________________
> pypy-dev at codespeak.net
> http://codespeak.net/mailman/listinfo/pypy-dev
>



-- 
Gabriel Lavoie
glavoie at gmail.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/pypy-dev/attachments/20100330/6305efe4/attachment.html>