public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/66866] [miscompile] incorrect load address on manual vector shuffle
Date: Tue, 14 Jul 2015 12:26:00 -0000	[thread overview]
Message-ID: <bug-66866-4-gPrYmYKwAa@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-66866-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66866

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
More reduced, fails at -O1:

extern "C" void abort (void);
typedef long long __m128i __attribute__ ((__vector_size__ (16),
__may_alias__));
typedef short A __attribute__((__may_alias__));
__m128i __attribute__((noinline))
shuf(const __m128i v)
{
  __m128i r;
  reinterpret_cast<A *>(&r)[5] = reinterpret_cast<const A *>(&v)[4];
  return r;
}
int main()
{
  __attribute__((aligned(16))) short mem[8] = { 0, 1, 2, 3, 4, 5, 6, 7 };
  *reinterpret_cast<__m128i *>(mem) = shuf (*reinterpret_cast<__m128i *>(mem));
  if (mem[5] != 4)
    abort ();
  return 0;
}


_Z4shufDv2_x:
.LFB527:
        .cfi_startproc
        movaps  %xmm0, -24(%rsp)
        pxor    %xmm0, %xmm0
        pinsrw  $5, -24(%rsp), %xmm0
        ret


  parent reply	other threads:[~2015-07-14 12:26 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-14 10:38 [Bug target/66866] New: " kretz at kde dot org
2015-07-14 12:14 ` [Bug target/66866] " rguenth at gcc dot gnu.org
2015-07-14 12:26 ` rguenth at gcc dot gnu.org [this message]
2015-07-14 12:45 ` rguenth at gcc dot gnu.org
2015-07-14 12:47 ` rguenth at gcc dot gnu.org
2015-07-14 12:51 ` rguenth at gcc dot gnu.org
2015-07-15  9:05 ` ubizjak at gmail dot com
2015-07-15 22:20 ` uros at gcc dot gnu.org
2015-07-15 22:23 ` [Bug target/66866] [4.9/5 Regression] " ubizjak at gmail dot com
2015-07-17 20:25 ` uros at gcc dot gnu.org
2015-07-17 21:40 ` uros at gcc dot gnu.org
2015-07-17 21:41 ` ubizjak 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-66866-4-gPrYmYKwAa@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).