[Bug middle-end/53667] [4.6/4.7/4.8 Regression] Cray pointer: Wrong result with optimizations

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53667

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-09-07 09:01:10 UTC ---
Ok, so fixing this will pessimize gfortran.dg/c_ptr_tests_16.f90 as

  print '(z8)', a

will now clobber a even though we have

  _gfortran_transfer_integer_write (&dt_parm.1, &a, 8);

marked with ".wR" (that is, &a is specified as to not escape and not be
clobbered).  Still, as &dt_parm.1 is clobbered it possibly gets assigned
&a and by means of being clobbered it will clobber &a ...

Not sure if we can restrict non-escaping to also not escape to other
parameters?  Possibly we should, otherwise this property won't be very
useful.