On Wed, 6 Dec 2023, Tamar Christina wrote:
> Hi All,
>
> While waiting for reviews I've continued to run more test.
> In this case this was one found running 32-bit systems.
>
> While we calculate the right latch count for the epilog,
> the vectorizer overrides SCEV and so unrolling goes wrong.
>
> This updates the bounds for the case where we've peeled a
> vector iteration.
>
> Testcase in early break testsuite adjusted to test for this
> and I'll merge this commit in the main one.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
OK.
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> * tree-vect-loop-manip.cc (vect_do_peeling): Adjust bounds.
>
> --- inline copy of patch --
> diff --git a/gcc/tree-vect-loop-manip.cc b/gcc/tree-vect-loop-manip.cc
> index
> 4edde4443ecd98775972f39b3fe839255db12b04..7d48502e2e46240553509dfa6d75fcab7fea36d3
> 100644
> --- a/gcc/tree-vect-loop-manip.cc
> +++ b/gcc/tree-vect-loop-manip.cc
> @@ -3457,6 +3457,12 @@ vect_do_peeling (loop_vec_info loop_vinfo, tree
> niters, tree nitersm1,
> if (bound_scalar.is_constant (&bound))
> {
> gcc_assert (bound != 0);
> + /* Adjust the upper bound by the extra peeled vector iteration if we
> + are an epilogue of an peeled vect loop and not VLA. For VLA the
> + loop bounds are unknown. */
> + if (LOOP_VINFO_EARLY_BREAKS_VECT_PEELED (loop_vinfo)
> + && vf.is_constant ())
> + bound += vf.to_constant ();
> /* -1 to convert loop iterations to latch iterations. */
> record_niter_bound (epilog, bound - 1, false, true);
> scale_loop_profile (epilog, profile_probability::always (),
>
>
>
>
>
--
Richard Biener <[email protected]>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
