https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110762
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
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CC|uros at gcc dot gnu.org |
Target Milestone|11.5 |13.3
--- Comment #21 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Richard Biener from comment #20)
> Thanks a lot. So this should now be fully fixed in GCC 14. The original
> testcase is also broken in GCC 11, 12 and 13 but not 10, but I'm not sure
> how far we'd want to backport this change - I'd consider the 13 branch but
> that's probably it. After some time soaking, that is.
The issue can be triggered only with a specially crafted code (such as the one
in Comment #0 / Comment #12) that deliberatelly exposes the problem. Otherwise,
the approach from PR 95046 is quite robust, and there have been no PRs in this
area reported, although V2SF is auto-vectorized by default.
The patch is written in such a way to minimize exposure to subregs (the
temporary V4SFmode output register is used and later copied via subreg to
target V2SFmode operand) to avoid eventual problems in RA. GCC 13.2 was just
released, so I think the patch could be backported to gcc-13 branch in the
first week of august, but as you propose, only to gcc-13 branch, and not any
further.
