[Bug c++/33810] New: gcc 4.1.2 mangles results on x86_64 in bitfield operations

[Bug c++/33810] New: gcc 4.1.2 mangles results on x86_64 in bitfield operations

[satyaakam at yahoo dot co dot in]

Run the test case on a x86_64 bit machine to see how gcc 4.1.2 mangles results
in under Linux

We have tested the test case using 3.2.3 Compiler on RHEL 3 on both 32 as well
as 64 bit OS it works well.

Compile the test case provided with the following steps

$gcc -g -I. -Wall -m64 -c bar.c
$g++ -g -I. -Wall -m64 -o foo foo.c bar.o

Actual results: once you run the program foo you will see the following result

foo: i is 3.
bar: i is 3221205968.

Expected results:

foo: i is 3.
bar: i is 3.

Additional info: Test Case follows


----- bar.h -----

typedef struct {

 unsigned b1:16;

 unsigned b2:16;

} foo;



#ifdef   __cplusplus

extern "C"

{

#endif



foo bar(unsigned);



#ifdef   __cplusplus

}

#endif




----- bar.c -----

#include <stdio.h>

#include <bar.h>



foo bar(unsigned i)

{

 foo myfoo;

 myfoo.b1=myfoo.b2=0;

 printf("bar: i is %u.\n",i);

 return(myfoo);

}





----- foo.c -----

#include <stdio.h>
#include <bar.h>

int main(void)

{

 foo myfoo;

 unsigned i = 3;

 printf("foo: i is %u.\n",i);

 myfoo = bar(i);

 return 0;

}


-- 
           Summary: gcc 4.1.2 mangles results on x86_64 in bitfield
                    operations
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: satyaakam at yahoo dot co dot in


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33810

[Bug c++/33810] gcc 4.1.2 mangles results on x86_64 in bitfield operations

[bangerth at dealii dot org]

------- Comment #1 from bangerth at dealii dot org  2008-01-13 03:10 -------
Confirmed. Here's a slightly simplified testcase:
-----------bar.h------------
typedef struct {
    unsigned : 16;
    unsigned : 16;
} foo;
-----------bar.c------------
#include <stdio.h>
#include <bar.h>

foo bar(unsigned i)
{
  printf("bar: i is %u.\n",i);
  foo myfoo;
  return myfoo;
}
-------------foo.cc------------
#include <stdio.h>
#include <bar.h>

extern "C" foo bar(unsigned int);

int main(void)
{
  foo myfoo;
  unsigned i = 3;
  printf("foo: i is %u.\n",i);
  myfoo = bar(i);
  return 0;
}
-------------------
tmp/g> gcc -I. -c bar.c
tmp/g> g++ -I. -o foo foo.c bar.o
tmp/g> ./foo 
foo: i is 3.
bar: i is 1289971520.

Something appears to go wrong when calling the extern "C" function...

This is a wrong-code regression on valid code.

W.


-- 

bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bangerth at dealii dot org,
                   |                            |mmitchel at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
           Keywords|                            |wrong-code
   Last reconfirmed|0000-00-00 00:00:00         |2008-01-13 03:10:24
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33810

[Bug c++/33810] gcc 4.1.2 mangles results on x86_64 in bitfield operations

[mmitchel at gcc dot gnu dot org]

-- 

mmitchel at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33810

[Bug c++/33810] [4.1 Regression] gcc 4.1.2 mangles results on x86_64 in bitfield operations

[rguenth at gcc dot gnu dot org]

-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu dot
                   |                            |org
      Known to fail|                            |4.1.3
      Known to work|                            |3.3.6 4.2.3 4.3.0
            Summary|gcc 4.1.2 mangles results on|[4.1 Regression] gcc 4.1.2
                   |x86_64 in bitfield          |mangles results on x86_64 in
                   |operations                  |bitfield operations
   Target Milestone|---                         |4.1.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33810

[Bug c++/33810] [4.1 Regression] gcc 4.1.2 mangles results on x86_64 in bitfield operations

[jsm28 at gcc dot gnu dot org]

------- Comment #2 from jsm28 at gcc dot gnu dot org  2008-07-04 16:15 -------
Closing 4.1 branch.


-- 

jsm28 at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.1.3                       |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33810