On Sun, 15 Jul 2012, William J. Schmidt wrote:
> The auto-vectorizer is overly aggressive when not constrained by the
> vectorizer cost model. Although the cost model is by no means perfect,
> it does a reasonable job of avoiding many poor vectorization decisions.
> Since the auto-vectorizer is enabled by default at -O3 and above, we
> should also enable the vectorizer cost model by default at -O3 and
> above.
>
> Bootstrapped and tested on powerpc64-unknown-linux-gnu with no new
> regressions. Ok for trunk?
I agree this makes sense. It probably will cause some missed-optimization
bugreports which means we need to make more target cost implementation
adjustments.
Thus, ok.
Thanks,
Richard.
> Thanks,
> Bill
>
>
> 2012-07-15 Bill Schmidt <wschm...@linux.ibm.com>
>
> * opts.c (default_option): Add -fvect-cost-model to default options
> at -O3 and above.
>
>
> Index: gcc/opts.c
> ===================================================================
> --- gcc/opts.c (revision 189481)
> +++ gcc/opts.c (working copy)
> @@ -501,6 +501,7 @@ static const struct default_options default_option
> { OPT_LEVELS_3_PLUS, OPT_funswitch_loops, NULL, 1 },
> { OPT_LEVELS_3_PLUS, OPT_fgcse_after_reload, NULL, 1 },
> { OPT_LEVELS_3_PLUS, OPT_ftree_vectorize, NULL, 1 },
> + { OPT_LEVELS_3_PLUS, OPT_fvect_cost_model, NULL, 1 },
> { OPT_LEVELS_3_PLUS, OPT_fipa_cp_clone, NULL, 1 },
> { OPT_LEVELS_3_PLUS, OPT_ftree_partial_pre, NULL, 1 },
>
>
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imend
