[Bug tree-optimization/59413] wrong code at -Os on x86_64-linux-gnu in both 32-bit and 64-bit modes

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59413

--- Comment #3 from Zhendong Su <su at cs dot ucdavis.edu> ---
(In reply to Jakub Jelinek from comment #2)
> I couldn't reproduce this either, neither -m32/-m64 helps, tried also
> r205733 and various other snapshots, everything prints 7.

I rebuilt r205734 with the same config

    configure --prefix=/usr/local/gcc-trunk --enable-languages=c,c++
--disable-werror --enable-multilib

and 

    make bootstrap-lean

It still fails for me at -Os: 

$ ./gcc -Os small.c; a.out
2
$ cat small.c
int printf (const char *, ...);

typedef unsigned int uint32_t;

uint32_t a;
int b;

int
main ()
{
  uint32_t c;
  for (a = 7; a <= 1; a++)
    {
      char d = a;
      c = d;
      b = a == c;
    }
  printf ("%d\n", a);
  return 0;
}