[Bug middle-end/20493] [4.0/4.1 Regression] Bootstrap failure because of aliased symbols

[roger at eyesopen dot com]

------- Additional Comments From roger at eyesopen dot com  2005-03-17 05:06 -------
Hmm, yep, probably caused by my change.

It looks like with my change fold_widened_comparison is now converting
(int)t == -1 into the equivalent t == (typeof(t))-1.  Normally, this
would be reasonable but the "special" semantics of
HAVE_canonical_funcptr_for_compare clearly screw this up.

My suggestion would be to add the following to the top of the subroutine
fold_widened_comparison:

#ifdef HAVE_canonicalize_funcptr_for_compare
  /* Disable this optimization if we're casting to a function pointer
     type on targets that require function pointer canonicalization.  */
  if (HAVE_canonicalize_funcptr_for_compare
      && TREE_CODE (shorter_type) == POINTER_TYPE
      && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
    return NULL_TREE;
#endif

Dave, could you give this a try and see if it restores bootstrap for you?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20493