public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/99117] [9/10/11 Regression] cannot accumulate std::valarray
Date: Tue, 23 Feb 2021 13:30:49 +0000 [thread overview]
Message-ID: <bug-99117-4-T0FPwXbOB2@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-99117-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99117
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jsm28 at gcc dot gnu.org
--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #13)
> So the valarray behavior boils down to
>
> struct _Array { int * __restrict m_data; };
>
> void foo (struct _Array dest, int *src, int n)
> {
> for (int i = 0; i < n; ++i)
> dest.m_data[i] = src[i];
> }
>
> which we treat similarly:
>
> _8 = MEM[(int *)_3 clique 1 base 0];
> MEM[(int *)_7 clique 1 base 1] = _8;
>
> and thus we'd vectorize "bogously" for example if src == dest.m_data + 1
I'd argue that passing such src to the function is invalid (for C, sure, C++
doesn't have restrict).
Because src is not based on dest.m_data in that case.
So, the big question is what passes that pointer that aliases it.
next prev parent reply other threads:[~2021-02-23 13:30 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-16 5:26 [Bug c++/99117] New: " yasui at icepp dot s.u-tokyo.ac.jp
2021-02-16 7:43 ` [Bug middle-end/99117] [9/10/11 Regression] " rguenth at gcc dot gnu.org
2021-02-16 7:59 ` [Bug libstdc++/99117] " rguenth at gcc dot gnu.org
2021-02-16 10:41 ` redi at gcc dot gnu.org
2021-02-16 11:01 ` redi at gcc dot gnu.org
2021-02-16 11:25 ` jakub at gcc dot gnu.org
2021-02-16 11:40 ` rguenther at suse dot de
2021-02-16 11:47 ` redi at gcc dot gnu.org
2021-02-16 11:54 ` rguenther at suse dot de
2021-02-16 14:07 ` redi at gcc dot gnu.org
2021-02-23 9:28 ` rguenth at gcc dot gnu.org
2021-02-23 10:35 ` redi at gcc dot gnu.org
2021-02-23 11:43 ` rguenther at suse dot de
2021-02-23 13:26 ` rguenth at gcc dot gnu.org
2021-02-23 13:30 ` jakub at gcc dot gnu.org [this message]
2021-02-23 13:56 ` jakub at gcc dot gnu.org
2021-02-23 14:17 ` jakub at gcc dot gnu.org
2021-02-23 14:20 ` jakub at gcc dot gnu.org
2021-06-01 8:19 ` [Bug libstdc++/99117] [9/10/11/12 " rguenth at gcc dot gnu.org
2022-05-27 9:44 ` [Bug libstdc++/99117] [10/11/12/13 " rguenth at gcc dot gnu.org
2022-06-28 10:43 ` jakub at gcc dot gnu.org
2023-07-07 10:39 ` [Bug libstdc++/99117] [11/12/13/14 " rguenth at gcc dot gnu.org
2024-02-08 21:34 ` redi at gcc dot gnu.org
2024-02-15 11:44 ` cvs-commit at gcc dot gnu.org
2024-02-16 15:12 ` [Bug libstdc++/99117] [11/12/13 " cvs-commit at gcc dot gnu.org
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bug-99117-4-T0FPwXbOB2@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).