public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/110931] [14 Regression] Dead Code Elimination Regression since r14-2890-gcc2003cd875
Date: Wed, 09 Aug 2023 01:35:29 +0000 [thread overview]
Message-ID: <bug-110931-4-gusmlspI7i@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-110931-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110931
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Blocks| |85316
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #2)
> Basically there is a missing VRP happening here:
> l.0_1 [irange] int [-INF, -65536][0, 0][65536, +INF]
> Partial equiv (b_6 pe8 l.0_1)
> <bb 3> :
> b_6 = (char) l.0_1;
> ...
> Obvious that b_6 will have the range [0,0] as the other parts of l.0_1 is
> outside of that range. But for some reason VRP didn't figure that out here
> ...
Oh it looks like we don't prop NONZERO back and I missed that when I first
looked at this.
In this case we have:
l&(short)(-1) == 0
But we don't record that in the above, only a range ...
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85316
[Bug 85316] [meta-bug] VRP range propagation missed cases
next prev parent reply other threads:[~2023-08-09 1:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-07 10:33 [Bug tree-optimization/110931] New: " theodort at inf dot ethz.ch
2023-08-07 14:57 ` [Bug tree-optimization/110931] " pinskia at gcc dot gnu.org
2023-08-07 15:11 ` pinskia at gcc dot gnu.org
2023-08-07 15:25 ` pinskia at gcc dot gnu.org
2023-08-07 16:07 ` pinskia at gcc dot gnu.org
2023-08-09 1:35 ` pinskia at gcc dot gnu.org [this message]
2024-03-07 23:25 ` law at gcc dot gnu.org
2024-03-09 6:50 ` law at gcc dot gnu.org
2024-05-07 7:41 ` [Bug tree-optimization/110931] [14/15 " 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-110931-4-gusmlspI7i@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).