public inbox for gcc-prs@sourceware.org
help / color / mirror / Atom feed
From: lprimak@hope.nyc.ny.us
To: gcc-gnats@gcc.gnu.org
Subject: c++/7322: Code to Compute Numeric Limits "runs away" when -O<any> used
Date: Mon, 15 Jul 2002 19:56:00 -0000	[thread overview]
Message-ID: <20020716024640.20402.qmail@sources.redhat.com> (raw)


>Number:         7322
>Category:       c++
>Synopsis:       Code to Compute Numeric Limits "runs away" when -O<any> used
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jul 15 19:56:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Lenny Primak
>Release:        gcc version 3.1
>Organization:
>Environment:
(the OS is probably irrelevant)
Solaris 8/x86, Oct. 01 release,
gcc 3.1 as posted on Sunfreeware.com

ash-2.03$ gcc -v
Reading specs from /usr/local/lib/gcc-lib/i386-pc-solaris2.8/3.1/specs
Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --disable-nls
Thread model: posix
bash-2.03$ gcc -v
Reading specs from /usr/local/lib/gcc-lib/i386-pc-solaris2.8/3.1/specs
Configured with: ../configure --with-as=/usr/ccs/bin/as --with-ld=/usr/ccs/bin/ld --disable-nls
Thread model: posix
gcc version 3.1
>Description:
The code works correctly when not using the optimize (-O) switch.
Incorrect code is produced that causes the process
to "run away" and eats 100% of the cpu when any kind
of optimization switch is used.
>How-To-Repeat:
bash-2.03$ c++ -O1 limits.cpp 
bash-2.03$ ./a.out
:
#undef _LPLIM_LIMITS
#define _LPLIM_CHAR_BIT 8
#define _LPLIM_BOOL_MIN !!0 /* sizeof (bool) = 1 */
#define _LPLIM_BOOL_MAX !0
#define _LPLIM_CHAR_MAX 127 /* sizeof (char) = 1 */
#define _LPLIM_CHAR_MIN (-_LPLIM_CHAR_MAX - 1)
(hangs/runs away here) ^C
bash-2.03$ 
>Fix:
None Available
>Release-Note:
>Audit-Trail:
>Unformatted:
----gnatsweb-attachment----
Content-Type: application/octet-stream; name="limits.cpp"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="limits.cpp"
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             reply	other threads:[~2002-07-16  2:56 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-07-15 19:56 lprimak [this message]
2002-07-16  1:41 nathan

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=20020716024640.20402.qmail@sources.redhat.com \
    --to=lprimak@hope.nyc.ny.us \
    --cc=gcc-gnats@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).