public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "mshawcroft at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/61633] AArch64 SISD ASHR instruction split clobbers input register.
Date: Mon, 30 Jun 2014 07:55:00 -0000	[thread overview]
Message-ID: <bug-61633-4-pcovQcXURy@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-61633-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61633

--- Comment #1 from mshawcroft at gcc dot gnu.org ---
Author: mshawcroft
Date: Mon Jun 30 07:54:59 2014
New Revision: 212137

URL: https://gcc.gnu.org/viewcvs?rev=212137&root=gcc&view=rev
Log:
[AArch64] Fix register clobber in, aarch64_ashr_sisd_or_int_<mode>3 split.

PR target/61633

The two split patterns associated with
aarch64_ashr_sisd_or_int_<mode>3 split the instruction into a NEG
followed by an SHL.  The split uses one of the input operands as a
scratch register to hold the output of the NEG resulting in register
corruption.

This patch adjusts the splits to use the output operand as the scratch
register.

2014-06-30  Marcus Shawcroft  <marcus.shawcroft@arm.com>

       PR target/61633
       * config/aarch64/aarch64.md (*aarch64_ashr_sisd_or_int_<mode>3):
       Add alternative; make early clobber.  Adjust both split patterns
       to use operand 0 as the working register.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/config/aarch64/aarch64.md


  reply	other threads:[~2014-06-30  7:55 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-27 15:46 [Bug target/61633] New: " mshawcroft at gcc dot gnu.org
2014-06-30  7:55 ` mshawcroft at gcc dot gnu.org [this message]
2014-06-30 11:59 ` [Bug target/61633] " mshawcroft at gcc dot gnu.org
2014-06-30 12:00 ` mshawcroft at gcc dot gnu.org
2014-07-01 21:18 ` pinskia 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-61633-4-pcovQcXURy@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).