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* [Bug c/18426] New: -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules
@ 2004-11-11  6:32 torger at ludd dot luth dot se
  2004-11-11  6:35 ` [Bug c/18426] " pinskia at gcc dot gnu dot org
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: torger at ludd dot luth dot se @ 2004-11-11  6:32 UTC (permalink / raw)
  To: gcc-bugs

/* 
 
x86 platform. 
 
This simple program with the obvious breaking of strict aliasing  
rules does not generate a warning with -Wstrict-aliasing 
 
gcc -Wall -Wstrict-aliasing test.c 
 
tested on Pentium 4 
 
gcc 3.4.2, gcc 3.3.5 and gcc 3.2.3, as built for debian unstable 
2004 Nov 9 
 
*/ 
 
#include <stdio.h> 
 
unsigned long 
hash(void *key) 
{ 
    unsigned long long u[1]; 
    u[0] = *(unsigned long long *)key; 
    return ((unsigned long *)u)[0] ^ ((unsigned long *)u)[1]; 
} 
 
int 
main(void) 
{ 
    unsigned long long ull; 
 
    ull = 0xDEADBEAF; 
     
    fprintf(stderr, "%08lX\n", hash(&ull)); 
    return 0; 
}

-- 
           Summary: -Wstrict-aliasing fails to report simple case of
                    breaking strict aliasing rules
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: torger at ludd dot luth dot se
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18426


^ permalink raw reply	[flat|nested] 4+ messages in thread
* [Bug c/18426] -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules
  2004-11-11  6:32 [Bug c/18426] New: -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules torger at ludd dot luth dot se
@ 2004-11-11  6:35 ` pinskia at gcc dot gnu dot org
  2004-11-11 12:33 ` giovannibajo at libero dot it
  2005-09-18  1:40 ` pinskia at gcc dot gnu dot org
  2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-11-11  6:35 UTC (permalink / raw)
  To: gcc-bugs



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|minor                       |enhancement
           Keywords|                            |diagnostic


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18426


^ permalink raw reply	[flat|nested] 4+ messages in thread
* [Bug c/18426] -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules
  2004-11-11  6:32 [Bug c/18426] New: -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules torger at ludd dot luth dot se
  2004-11-11  6:35 ` [Bug c/18426] " pinskia at gcc dot gnu dot org
@ 2004-11-11 12:33 ` giovannibajo at libero dot it
  2005-09-18  1:40 ` pinskia at gcc dot gnu dot org
  2 siblings, 0 replies; 4+ messages in thread
From: giovannibajo at libero dot it @ 2004-11-11 12:33 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From giovannibajo at libero dot it  2004-11-11 12:32 -------
A little analysys here:
http://gcc.gnu.org/ml/gcc-bugs/2004-11/msg01216.html

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-11-11 12:32:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18426


^ permalink raw reply	[flat|nested] 4+ messages in thread
* [Bug c/18426] -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules
  2004-11-11  6:32 [Bug c/18426] New: -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules torger at ludd dot luth dot se
  2004-11-11  6:35 ` [Bug c/18426] " pinskia at gcc dot gnu dot org
  2004-11-11 12:33 ` giovannibajo at libero dot it
@ 2005-09-18  1:40 ` pinskia at gcc dot gnu dot org
  2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2005-09-18  1:40 UTC (permalink / raw)
  To: gcc-bugs


------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-18 01:39 -------
Fixed in 4.1.0 and above.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18426


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2005-09-18  1:40 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-11-11  6:32 [Bug c/18426] New: -Wstrict-aliasing fails to report simple case of breaking strict aliasing rules torger at ludd dot luth dot se
2004-11-11  6:35 ` [Bug c/18426] " pinskia at gcc dot gnu dot org
2004-11-11 12:33 ` giovannibajo at libero dot it
2005-09-18  1:40 ` pinskia at gcc dot gnu dot org

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