Re: gcc4.0 autovect-branch

[Daniel Berlin <dberlin at dberlin dot org>]

On Fri, 2004-12-17 at 10:16 -0800, Devang Patel wrote:
> On Dec 17, 2004, at 8:47 AM, Villemin Ryusuke wrote:
> 
> > Hi,
> >
> > I might be missing something simple and obvious, but I can't find out 
> > what :
> > I picked up gcc4.0 in the autovect-branch, compiled it successfully 
> > but can t make it vectorize anything.
> >
> > int a[256], b[256], c[256];
> >
> > foo () {
> >   int i;
> >   for (i=0; i<256; i++){
> >     a[i] = b[i] + c[i];
> >   }
> > }
> >
> > compiled with :
> > "gcc -O2 -msse2 -ftree-vectorize -fdump-tree-vect-stats vecto.c".
> 
> Compiler is able to vectorize this loop on powerpc-darwin.
> 
> > I expect to see a "LOOP VECTORIZED." (or at least "not vectorized:"), 
> > but I have nothing...
> 
> Do you see vecto.c.t53.vect ? What does it say?
> If you do not see vecto.c.t53.vect then somehow vectorizer is not 
> triggered.
> 
> -
> Devang

I get the feeling he expected it to print something to stderr/stdout,
like intel's compiler does if you tell it to vectorize, and that this is
what he thought the dump option did.

Villemin, this is not the case.
-fdump-tree-<passname> will produce a <sourcename>.t<pass
number>.<passname>  dumpfile that contains dumps from that pass.

*That* is where the LOOP VECTORIZED text will be printed.
--Dan