[Bug tree-optimization/32721] CCP removes volatile qualifiers.

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #5 from rguenth at gcc dot gnu dot org  2007-07-13 12:19 -------
Actually, the optimized dump ist still correct:

main ()
{
  int D.2011;

<bb 2>:
  spinlock[0] = 0;
  spinlock[1] = 0;

<bb 3>:
  D.2011 = spinlock[0];
  if (D.2011 != 0)
    goto <bb 3>;
  else
    goto <bb 4>;

<bb 4>:
  return;

}

spinlock[0] is re-loaded in every loop iteration.  Likewise the assembly
is correct.  Only if I remove the volatile qualifier from the declaration
of spinlock then FRE removes the redundancy.  And this is because while
we keep the has_volatile_ops on the stmt after the propagation of the
pointer, the first alias pass clears it.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32721