[Bug c/35753] New: apparent integer math bug

[regehr at cs dot utah dot edu]

This is for "gcc (GCC) 4.3.0".

This function returns different values at -O1 and -O2:

int func_5 (void) {
  int g_4 = 0x4E6D4F28;
  return 0 <= (6 * g_4);
}

At -O1 output looks good:

func_5:
        pushl   %ebp
        movl    %esp, %ebp
        movl    $0, %eax
        popl    %ebp
        ret

At -O2 not good:

func_5:
        pushl   %ebp
        movl    $1, %eax
        movl    %esp, %ebp
        popl    %ebp
        ret


-- 
           Summary: apparent integer math bug
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: regehr at cs dot utah dot edu
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35753