hi,
they should work completely independently from vectorization. It does not
matter if vectorizaton is already run or not, they will apply
if You enable them by flags.
konrad
From: Jack Howarth <[EMAIL PROTECTED]>
To: Dorit Nuzman/Haifa/[EMAIL PROTECTED]
Cc: gcc@gcc.gnu.org, Konrad Trifunovic/Haifa/Contr/[EMAIL PROTECTED]
Date: 13/08/2008 17:24
Subject: Re: vectorization, -floop-strip-mine, -floop-block and
-floop-interchange
Dorit,
So it is correct to say that any loop that is vectorized is
removed from consideration for these other loop optimizations?
I ask because I am wondering if I should be testing these new
loop optimizations at -O2 in order to see their full effect
(without vectorization inhibiting their use).
Jack
On Wed, Aug 13, 2008 at 05:08:53PM +0300, Dorit Nuzman wrote:
> > Can anyone explain the relationship between the current
vectorization
> > optimizations in the gcc trunk compiler and the new -floop-strip-mine,
> > -floop-interchange and -floop-block loop optimizations? Which takes
> > precedence and does one set block the other in any way? I would hope
> > that the new loop optimizations simply redefine the loops that are then
> > processed for vectorization so that both sets of optimizations can
> > be in effect at the same time. Thanks in advance for any clarifications
> > on how these optimizations interact with each other.
>
> There's currently no interaction between the Graphite optimizations and
> vectorization. I don't know what considerations/cost-model Graphite uses
> before applying its optimizations, but vectorization is not one of them.
We
> are now starting to look into teaching Graphite to take into account
> factors that affect the applicability and profitability of vectorization,
> but this work is in a very initial stage.
>
> dorit
>
> > Jack
