public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "gcc-bugzilla at mkarcher dot dialup.fu-berlin.de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/63783] [4.9/5 Regression] [SH] Miscompilation of boolean negation on SH4 using -O2
Date: Wed, 12 Nov 2014 23:25:00 -0000 [thread overview]
Message-ID: <bug-63783-4-c0ff7kVo19@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-63783-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63783
Michael Karcher <gcc-bugzilla at mkarcher dot dialup.fu-berlin.de> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |gcc-bugzilla at mkarcher dot dialu
| |p.fu-berlin.de
--- Comment #3 from Michael Karcher <gcc-bugzilla at mkarcher dot dialup.fu-berlin.de> ---
Created attachment 33954
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33954&action=edit
Remove assumption that "not" is logical negate
Indeed the treg combine pass is broken. Thanks to the nicely documented code,
it could easily be determined, that this optimization pass contains the wrong
assumption that "not" is an assembler instruction that can be used for logical
negation of a register. As this is a bitwise negate instruction, it can not be
used that way.
As I was unable to find a machine instruction that performs logical negation, I
prepared a patch that completely removes the parts that rely on a logical
negate instruction, while keeping all other aspects on the optimization pass
intact.
next prev parent reply other threads:[~2014-11-12 23:25 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-08 20:52 [Bug c/63783] New: gcc-4.9: " glaubitz at physik dot fu-berlin.de
2014-11-09 1:12 ` [Bug target/63783] [4.9/5 Regression] [SH] " kkojima at gcc dot gnu.org
2014-11-09 7:14 ` olegendo at gcc dot gnu.org
2014-11-12 23:25 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de [this message]
2014-11-16 2:36 ` olegendo at gcc dot gnu.org
2014-11-16 7:37 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-16 8:24 ` olegendo at gcc dot gnu.org
2014-11-16 10:02 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-16 10:41 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-16 11:01 ` olegendo at gcc dot gnu.org
2014-11-16 12:24 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-16 18:54 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-16 23:44 ` olegendo at gcc dot gnu.org
2014-11-19 13:27 ` rguenth at gcc dot gnu.org
2014-11-21 3:41 ` olegendo at gcc dot gnu.org
2014-11-21 18:53 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-22 3:28 ` olegendo at gcc dot gnu.org
2014-11-22 3:33 ` olegendo at gcc dot gnu.org
2014-11-22 10:14 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-22 10:39 ` olegendo at gcc dot gnu.org
2014-11-22 11:07 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-22 15:34 ` olegendo at gcc dot gnu.org
2014-11-22 15:37 ` gcc-bugzilla at mkarcher dot dialup.fu-berlin.de
2014-11-22 15:50 ` olegendo at gcc dot gnu.org
2014-11-22 16:08 ` olegendo at gcc dot gnu.org
2014-11-24 16:57 ` rguenth 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-63783-4-c0ff7kVo19@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).