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Re: regarding autovectorization and prefetching
- From: ranjith kumar <ranjit_kumar_b4u at yahoo dot co dot uk>
- To: gcc-help at gcc dot gnu dot org
- Date: Sun, 4 Mar 2007 19:30:54 +0000 (GMT)
- Subject: Re: regarding autovectorization and prefetching
--- Tim Prince <tprince@myrealbox.com> wrote:
> ranjith kumar wrote:
> > 1) gcc manuals says -fprefetch-loop-arrays option
> > inserts prefetch instructions automatically.
> > Where can I get an example .c program for which
> gcc
> > inserts prefetching instruction.
> >
> > 2) Similarly to the autovectorization.
> > Thanks in advance.
> >
> >
> You might specify what target you are interested in.
> As x86-64 targets
> do better with hardware prefetch than software
> prefetch, for the simple
> cases, I don't find the latter so interesting.
> There are test cases for -ftree-vectorize in the
> testsuite, both in the
> language parts and the tree-lang testsuite.
> gfortran-4.3 does a
> consistently good job on vectorization of the simple
> cases. gcc
> vectorizes effectively several of the gfortran
> library functions,
> including matmul.
>
1)Where can I get test cases. I have searched in
google. but it sucked.
2)The above two optimizations are done for C programs
also. Am I right?
3)From which version of gcc they are enabled?
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