[pypy-dev] Loop invaraints

[Hakan Ardo]

On Sun, Aug 29, 2010 at 1:04 PM, Armin Rigo <arigo at tunes.org> wrote:
>
> I'm not saying that loop-invariant code motion could also have a
> negative effect on large loops; I think it's a pure win, so it's
> probably worth a try.  I'm just giving a warning: it may not help much
> in the case of a "general Python program doing lots of stuff", but only
> in the case of small numerical computation loops.

Right. I write a lot of numerical computation loops these days, both
small and somewhat bigger, and I am typically force to write them in C
to get decent performance. So the motivation here would rater be to
broaden the usability of python than to improve performance of
exciting python programs.

Another motivation might be to help pypy developers focus on the
important instruction while staring at traces, ie by hiding the
instructions that will be inserted only once :)


-- 
Håkan Ardö