fold_builtin_memcpy cannot optimize <retval>?

[Mark Mitchell]

Jeffrey A Law wrote:

> I'm not an expert on the differences in the semantics of POINTER_TYPE
> and REFERENCE_TYPE, but I do know that I've been treating them as
> effectively the same.

The only difference is that a REFERENCE_TYPE object can never be NULL. 
Other than that, they are identical.  (In C++, you cannot assign to a 
reference, but that is expressed by TREE_READONLY on the object.)

I think that it makes sense to use POINTER_TYPE_P almost everywhere in 
the middle-end.  The other choices is to introduce explicit NOP_EXPRs to 
do the conversions -- but that's just a waste of memory, in my opinion.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304