On i686 and amd64, I get the following ICE: 
 
$ cat t.i 
static int foo (char *p) 
{ 
  if (! (*p & ~0x7f) ) ; 
} 
 
$ ../cc1 t.i 
 foo 
t.i: In function `foo': 
t.i:3: internal compiler error: in invert_truthvalue, at fold-const.c:2344 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <URL:http://gcc.gnu.org/bugs.html> for instructions. 
 
This is a regression on the 3.3 branch, 3.3.1 works just fine.