public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug middle-end/31354] New: NaN should only fail comparisons for equality
@ 2007-03-25 22:22 tkoenig at gcc dot gnu dot org
2007-03-25 22:27 ` [Bug middle-end/31354] " pinskia at gcc dot gnu dot org
2007-04-28 0:31 ` pinskia at gcc dot gnu dot org
0 siblings, 2 replies; 3+ messages in thread
From: tkoenig at gcc dot gnu dot org @ 2007-03-25 22:22 UTC (permalink / raw)
To: gcc-bugs
I'm guessing at middle-end here, maybe it is target...
I don't think it is correct for NaNs to fail any comparison.
They should only fail comparisons which include equality.
$ cat compare.c
#include <stdio.h>
int main()
{
float nan, x;
nan = 0.0;
nan = nan / nan;
x = 3.2;
printf("%f\n", nan);
printf("%d %d %d %d\n", x > nan, x < nan, x >= nan, x <= nan);
return 0;
}
$ gcc compare.c && ./a.out
nan
0 0 0 0
$ gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /home/ig25/gcc/trunk/configure --prefix=/home/ig25
--enable-maintainer-mode --enable-languages=c,fortran
Thread model: posix
gcc version 4.3.0 20070317 (experimental)
--
Summary: NaN should only fail comparisons for equality
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tkoenig at gcc dot gnu dot org
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31354
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/31354] NaN should only fail comparisons for equality
2007-03-25 22:22 [Bug middle-end/31354] New: NaN should only fail comparisons for equality tkoenig at gcc dot gnu dot org
@ 2007-03-25 22:27 ` pinskia at gcc dot gnu dot org
2007-04-28 0:31 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-03-25 22:27 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2007-03-26 00:27 -------
NaN's are unordered so they will compare false for ordered operators.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31354
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/31354] NaN should only fail comparisons for equality
2007-03-25 22:22 [Bug middle-end/31354] New: NaN should only fail comparisons for equality tkoenig at gcc dot gnu dot org
2007-03-25 22:27 ` [Bug middle-end/31354] " pinskia at gcc dot gnu dot org
@ 2007-04-28 0:31 ` pinskia at gcc dot gnu dot org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-04-28 0:31 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from pinskia at gcc dot gnu dot org 2007-04-28 01:31 -------
Not a bug as already explained.
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31354
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2007-04-28 0:31 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-03-25 22:22 [Bug middle-end/31354] New: NaN should only fail comparisons for equality tkoenig at gcc dot gnu dot org
2007-03-25 22:27 ` [Bug middle-end/31354] " pinskia at gcc dot gnu dot org
2007-04-28 0:31 ` pinskia at gcc dot gnu dot org
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).