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Re: [RFC] Matrix Flattening optimization
On Thu, 2006-03-02 at 12:48 -0500, Daniel Jacobowitz wrote:
> Just to clarify:
>
> On Thu, Mar 02, 2006 at 12:43:54PM -0500, Daniel Berlin wrote:
> > I'd imagine fortran programs would find it useful as well, as do a lot
> > of floating point array intensive apps. The fact that it helps equake is
> > not some well known hack, it's just from getting better locality, AFAIK.
>
> I know this, which is why I what I was trying to ask was...
>
> > In general, combining malloc calls and hoisting them out of loops is a
> > win, if you couldn't vectorize or interchange the original loop (due to
> > dependences, etc).
>
> ...whether this occured often enough in Real Code to bother.
Like I said, a quick grep showed it occurred a bnuch of times in code
i've just got sitting around (image decoder code, etc).
>
> How would Fortran programs find it useful? Shouldn't the Fortran
> compiler be generating the array flat in the first place?
Probably. I don't know if it always does though.
>