The current gcc trunk produces wrong code (that hangs) for the following testcase on x86_64-linux when compiled at -O3 in both 32-bit and 64-bit modes. 

This is a regression from 4.8.x.

It might be related to 58143, but 58143 also fails for 4.8. 


$ gcc-trunk -v
gcc version 4.9.0 20130822 (experimental) [trunk revision 201915] (GCC) 
$ gcc-4.8 -O3 reduced.c
$ a.out
$ gcc-trunk -O2 reduced.c
$ a.out
$ gcc-trunk -O3 reduced.c
$ a.out
^C
$ 


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

int a, b, d, e, f, *g, h, i;
volatile int c;

char foo (unsigned char p)
{
  return p + 1;
}

int bar () 
{
  for (h = 0; h < 3; h = foo (h))
    {
      c;
      for (f = 0; f < 1; f++)
	{
	  i = a && 0 < -2147483647 - h ? 0 : 1;
	  if (e)
	    for (; d;)
	      b = 0;
	  else
	    g = 0;
	}
    }
  return 0;
}

int main ()
{
  bar ();
  return 0;
}