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/94103] Wrong optimization: reading value of a variable changes its representation for optimizer
Date: Thu, 12 Mar 2020 13:21:45 +0000 [thread overview]
Message-ID: <bug-94103-4-d6GGFCh8uj@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94103-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94103
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Status|NEW |ASSIGNED
Known to work| |10.0
--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
commit 1dc00a8ec9aeba86b74b16bff6f171824bb7b4a1 (HEAD -> master, origin/master,
origin/HEAD)
Author: Richard Biener <rguenther@suse.de>
Date: Thu Mar 12 14:18:35 2020 +0100
tree-optimization/94103 avoid CSE of loads with padding
VN currently replaces a load of a 16 byte entity 128 bits of precision
(TImode) with the result of a load of a 16 byte entity with 80 bits of
mode precision (XFmode). That will go downhill since if the padding
bits are not actually filled with memory contents those bits are
missing.
2020-03-12 Richard Biener <rguenther@suse.de>
PR tree-optimization/94103
* tree-ssa-sccvn.c (visit_reference_op_load): Avoid type
punning when the mode precision is not sufficient.
* gcc.target/i386/pr94103.c: New testcase.
next prev parent reply other threads:[~2020-03-12 13:21 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-09 17:45 [Bug middle-end/94103] New: " ch3root at openwall dot com
2020-03-09 17:46 ` [Bug middle-end/94103] " ch3root at openwall dot com
2020-03-09 17:50 ` pinskia at gcc dot gnu.org
2020-03-09 22:30 ` ch3root at openwall dot com
2020-03-10 9:39 ` [Bug target/94103] " rguenth at gcc dot gnu.org
2020-03-10 13:41 ` ch3root at openwall dot com
2020-03-12 4:13 ` law at redhat dot com
2020-03-12 13:21 ` rguenth at gcc dot gnu.org [this message]
2020-03-12 13:23 ` rguenth at gcc dot gnu.org
2020-03-12 13:36 ` marxin at gcc dot gnu.org
2020-03-20 12:32 ` ch3root at openwall dot com
2020-03-20 14:25 ` rguenther at suse dot de
2020-03-20 14:44 ` schwab@linux-m68k.org
2020-03-20 16:29 ` ch3root at openwall dot com
2020-03-20 16:41 ` rguenther at suse dot de
2020-03-20 17:47 ` ch3root at openwall dot com
2020-03-20 17:53 ` rguenther at suse dot de
2020-04-02 14:49 ` cvs-commit at gcc dot gnu.org
2020-04-15 9:58 ` 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-94103-4-d6GGFCh8uj@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).