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 target/102143] ABI incompatibility with clang when passing 32bit vectors on 32bit i686
Date: Wed, 01 Sep 2021 07:32:44 +0000	[thread overview]
Message-ID: <bug-102143-4-PF9YUxhHPu@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-102143-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102143

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Well, we already have the ABI ISA dependent,
typedef int __v8si __attribute__((__vector_size__ (32)));

__v8si
foo (__v8si x, __v8si y)
{
  return x + y;
}
has different ABI based on -mavx or -mno-avx, etc.  For -mno-avx we emit a
warning:
/tmp/test.c: In function ‘foo’:
/tmp/test.c:5:1: warning: AVX vector return without AVX enabled changes the ABI
[-Wpsabi]
    5 | {
      | ^
/tmp/test.c:4:1: note: the ABI for passing parameters with 32-byte alignment
has changed in GCC 4.6
    4 | foo (__v8si x, __v8si y)
      | ^~~
/tmp/test.c:4:1: warning: AVX vector argument without AVX enabled changes the
ABI [-Wpsabi]

So, depending on what we decide, if the ABI will be ISA dependent, we want a
warning like the above one.

  parent reply	other threads:[~2021-09-01  7:32 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-31  8:45 [Bug target/102143] New: " ubizjak at gmail dot com
2021-08-31 13:36 ` [Bug target/102143] " hjl.tools at gmail dot com
2021-09-01  7:24 ` ubizjak at gmail dot com
2021-09-01  7:28 ` ubizjak at gmail dot com
2021-09-01  7:32 ` jakub at gcc dot gnu.org [this message]
2021-09-01  7:33 ` ubizjak at gmail dot com
2021-09-02  2:02 ` hjl.tools at gmail dot com

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-102143-4-PF9YUxhHPu@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).