[Bug rtl-optimization/57321] New: static function call miscompiled at -Os and above

[dhazeghi at yahoo dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57321

            Bug ID: 57321
           Summary: static function call miscompiled at -Os and above
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dhazeghi at yahoo dot com

The testcase below is miscompiled by gcc 4.8 on x86_64-linux, resulting in a
segfault when built with -Os or higher optimization levels.  This does not
occur with gcc 4.7 or current trunk.  The segfault appears on line 8, where p
is dereferenced and compared.

$ gcc-4.8 -v
gcc version 4.8.0 (GCC) 
$ gcc-4.8 -O1 small.c
$ ./a.out 
$ gcc-4.7 -Os small.c
$ ./a.out 
$ gcc-4.8 -Os small.c
$ ./a.out 
Segmentation fault (core dumped)

------------------------

int a = 1;
int *b;
int **c;

static int
bar(int *p)
{
    if (*p == a)
    {
        int *i[7][1][9] = {{{ 0 }}};
        int **j[1][1][1];
        j[0][0][0] = &i[0][0][0] ;
        *b = &p != c;
    }
    return 0;
}


void
foo(int p, int q)
{
    int i = 0;
    if (bar (&i))
        ;
}

int
main()
{
    foo (0, 0);
    return 0;
}