[Bug tree-optimization/57875] New: wrong code at -O2 on x86_64-linux-gnu in 32-bit mode

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57875

            Bug ID: 57875
           Summary: wrong code at -O2 on x86_64-linux-gnu in 32-bit mode
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The current gcc trunk mis-compiles the following code on x86_64-linux at -O2 in
32-bit mode. This is a regression from 4.8.x. 

$ gcc-trunk -v
gcc version 4.9.0 20130710 (experimental) [trunk revision 200864] (GCC) 
$
$ gcc-trunk -m32 -O2 small.c
$ a.out
1
$ gcc-trunk -m32 -O1 small.c
$ a.out
0
$ gcc-trunk -m32 -O3 small.c
$ a.out
0
$ gcc-4.8 -m32 -O2 small.c
$ a.out
0
$ 


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


int printf (const char *, ...);

int a[1], b, c, d, f, i; 
char e[1];

int
main ()
{
  for (; i < 1; i++)
    if (!d) {
      if (!c) 
    f = 2;
      e[0] &= f ^= 0;
    }
  b = a[e[0] >> 1 & 1];
  printf ("%d\n", b);
  return 0;
}