public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
* [Bug c/30935] New: Wrong evaluation result
@ 2007-02-23 15:18 jrr at concept dot de
2007-02-23 15:20 ` [Bug c/30935] " jrr at concept dot de
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: jrr at concept dot de @ 2007-02-23 15:18 UTC (permalink / raw)
To: gcc-bugs
The following C program evaluates t.a to a *wrong* value of 5 instead of 9:
#include <stdio.h>
struct test {
int a;
};
int func(struct test* tp) {
tp->a = 8; /* this update is lost */
return 1;
}
int main(int ac, char** av) {
struct test t;
t.a = 4;
t.a += func(&t); /* t.a (=4) already loaded into a CPU register? */
printf("t.a=%d ", t.a);
if (t.a == 9) {
printf("OK\n");
return 0;
} else {
printf("BAD\n");
return 1;
}
}
# gcc bad_eval.c && ./a.out
t.a=5 BAD
The machine is a Fedora Core 6 Linux x86_64 box.
# uname -a
Linux titan 2.6.16-1.2080_FC5 #1 SMP Tue Mar 28 03:38:47 EST 2006 x86_64 x86_64
x86_64 GNU/Linux
# gcc -v
Using built-in specs.
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-libgcj-multifile
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk
--disable-dssi --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre
--with-cpu=generic --host=x86_64-redhat-linux
Thread model: posix
gcc version 4.1.0 20060304 (Red Hat 4.1.0-3)
--
Summary: Wrong evaluation result
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jrr at concept dot de
GCC build triplet: x86_64-redhat-linux
GCC host triplet: x86_64-redhat-linux
GCC target triplet: x86_64-redhat-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30935
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/30935] Wrong evaluation result
2007-02-23 15:18 [Bug c/30935] New: Wrong evaluation result jrr at concept dot de
@ 2007-02-23 15:20 ` jrr at concept dot de
2007-02-23 15:22 ` jrr at concept dot de
2007-02-23 15:36 ` rguenth at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: jrr at concept dot de @ 2007-02-23 15:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from jrr at concept dot de 2007-02-23 15:19 -------
Created an attachment (id=13099)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=13099&action=view)
Initial test case showing the bug.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30935
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/30935] Wrong evaluation result
2007-02-23 15:18 [Bug c/30935] New: Wrong evaluation result jrr at concept dot de
2007-02-23 15:20 ` [Bug c/30935] " jrr at concept dot de
@ 2007-02-23 15:22 ` jrr at concept dot de
2007-02-23 15:36 ` rguenth at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: jrr at concept dot de @ 2007-02-23 15:22 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from jrr at concept dot de 2007-02-23 15:22 -------
(In reply to comment #0)
> The machine is a Fedora Core 6 Linux x86_64 box.
Sorry, I meant "Fedora Core release 5 (Bordeaux)"
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30935
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c/30935] Wrong evaluation result
2007-02-23 15:18 [Bug c/30935] New: Wrong evaluation result jrr at concept dot de
2007-02-23 15:20 ` [Bug c/30935] " jrr at concept dot de
2007-02-23 15:22 ` jrr at concept dot de
@ 2007-02-23 15:36 ` rguenth at gcc dot gnu dot org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu dot org @ 2007-02-23 15:36 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from rguenth at gcc dot gnu dot org 2007-02-23 15:36 -------
*** This bug has been marked as a duplicate of 11751 ***
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30935
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2007-02-23 15:36 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2007-02-23 15:18 [Bug c/30935] New: Wrong evaluation result jrr at concept dot de
2007-02-23 15:20 ` [Bug c/30935] " jrr at concept dot de
2007-02-23 15:22 ` jrr at concept dot de
2007-02-23 15:36 ` rguenth 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).