[Bug rtl-optimization/47477] [4.6 regression] Sub-optimal mov at end of method

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47477

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rth at gcc dot gnu.org

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-27 17:45:33 UTC ---
Alternatively, this narrowing of > word mode operations could as well be done
during tree optimizations.  I think the FE is the only place which performs
them,
as can be seen if you modify your testcase to do:
void *
add (void *a, void *b)
{
  return (void *)(__INTPTR_TYPE__) ((long long)(__INTPTR_TYPE__) a + ((long
long)(__INTPTR_TYPE__) b & ~1L));
}
instead of
void *
add (void *a, void *b)
{
  long long tmp = (long long)(__INTPTR_TYPE__) a + ((long
long)(__INTPTR_TYPE__) b & ~1L);
  return (void *)(__INTPTR_TYPE__) tmp;
}

But unfortunately we have nothing which performs this later on (gimple-fold?).