http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58459
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- LIM does not move the invariant because it does not see that _7 in _7->key is always dereferenced in the innermost loop. This is because LIM computes this property as a basic-block property, not as a reference property (if all references are in the same form we could track that on a per reference basis). OTOH this again boils down to the fact that we do not have a code hoisting pass. PRE figures this out one level but fails to catch the third occurance for some reason (just testing with -fno-tree-forwprop). So, without major restructuring LIM won't do this and it certainly wouldn't do it with partial rewritten _7 as we have it now with the interesting loop still using the dereference form.
