public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "amacleod at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/31178] VRP can infer a range for b in a >> b and a << b
Date: Tue, 22 Mar 2022 14:21:22 +0000 [thread overview]
Message-ID: <bug-31178-4-9cUbCJIUeL@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-31178-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=31178
Andrew Macleod <amacleod at redhat dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |amacleod at redhat dot com
--- Comment #8 from Andrew Macleod <amacleod at redhat dot com> ---
Is this always true?
I implemented this for GCC13 in the new side-effect code, and its causing
problems in fortran.
In particular gfortran.dg/check_bits_1.f90 goes into an infinite loop. I am
seeing things like
nb = bit_size (i)
do shift = 0, nb
k = shiftl (i, shift) ! Fortran 2008
i = shiftr (k, shift)
So it appears to do shifts on [0, 32] rather than [0, 31], and when I go look
for fortran 2008 info, i find:
"Its value must be non-negative, and less than or equal to BIT_SIZE(I)"
so it seem [0, N] for fortran rather than [0, N)? Are there other language
issues as well?
next prev parent reply other threads:[~2022-03-22 14:21 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <bug-31178-4@http.gcc.gnu.org/bugzilla/>
2013-02-11 7:48 ` rguenth at gcc dot gnu.org
2013-02-11 8:00 ` jakub at gcc dot gnu.org
2022-03-22 14:21 ` amacleod at redhat dot com [this message]
2022-03-22 17:03 ` amacleod at redhat dot com
2022-03-23 8:08 ` rguenther at suse dot de
2022-03-23 8:26 ` jakub at gcc dot gnu.org
2022-03-23 8:31 ` jakub at gcc dot gnu.org
2022-04-05 17:58 ` amacleod at redhat dot com
2022-04-05 18:06 ` jakub at gcc dot gnu.org
2022-04-05 18:24 ` amacleod at redhat dot com
2022-04-06 6:00 ` rguenth at gcc dot gnu.org
2022-04-06 8:16 ` vincent-gcc at vinc17 dot net
2022-04-06 8:22 ` rguenther at suse dot de
2022-04-06 8:45 ` vincent-gcc at vinc17 dot net
2022-04-06 13:10 ` amacleod at redhat dot com
2022-04-06 13:13 ` jakub at gcc dot gnu.org
2022-04-06 13:16 ` rguenther at suse dot de
2024-06-20 16:07 ` pinskia at gcc dot gnu.org
2024-06-26 5:44 ` pinskia at gcc dot gnu.org
2007-03-14 21:13 [Bug tree-optimization/31178] New: " rguenth at gcc dot gnu dot org
2007-03-15 14:43 ` [Bug tree-optimization/31178] " rguenth at gcc dot gnu dot org
2009-02-08 14:21 ` steven at gcc dot gnu dot org
2009-02-08 14:47 ` rguenth at gcc dot gnu dot 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-31178-4-9cUbCJIUeL@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).