[Bug c++/15776] New: enum optimization produces wrong code

["gollin at informatik dot hu-berlin dot de" <gcc-bugzilla at gcc dot gnu dot org>]

The following program doesn't run properly when compiled with -O

#include <stdio.h>
 
enum OptionStateEnum
{
  SLEEPING,
  ACTIVE,
  INTENDED,
  DESIRED,
  EXECUTED,
  ABORTED
};
 
int main()
{
  OptionStateEnum l[2] = { EXECUTED, ACTIVE };
 
  OptionStateEnum state;
  for ( int i = 0; i < 2; ++i ) {
    state = l[i];
    printf( "state = %d\n", state );
    if ( ( state == DESIRED ) ||
         ( state == INTENDED ) ||
         ( state == ACTIVE ) ) {
      printf( "break state = %d\n", state );
      break;
    }
  }

  return 0;
}


The program was compiled using the following command:
gcc -O -g0 optimize-enum.cpp -o optimize-enum.exe

Resulting in the following output:
state = 4
break state = 4


When compiled with -O0 the output is as expected:
state = 4
state = 1
break state = 1

The problem also vanishes when checking for 4 or only 2 enums in the
if-statement. Or when assigning explicit values to the enums (0, 2, 4, 8, 16,
32, 64).

Cheers,
Michael Gollin

-- 
           Summary: enum optimization produces wrong code
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gollin at informatik dot hu-berlin dot de
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15776