Aliasing violation generated by fold_builtin_memcmp?

[Daniel Berlin]

On Fri, 2005-09-30 at 11:20 -0400, Richard Kenner wrote:
>     Uh, CAN_ALIAS_ALL seems like a very bad hack then.
>     You should simply be creating a pointed-to type that aliases set 0, and
>     using that for the pointed to type.
>     That is, after all, what alias set 0 is for.
> 
> That's easy enough for integer types, but creating multiple record types
> means duplicating lots of fields and layouts and is, in general, a mess.

But of course, it's the right thing to do when you've got one type that
can be aliased to anything through a pointer, and the other cannot.

> What's special here is the pointer type, not the underlying type.

Which means that everywhere that handles pointer types and aliasing has
to be modified to check this magic.

I still claim it is a hack, and a very bad one.

At the absolute least, it should be encapsulated in a function, maybe
"get_alias_set_of_pointed_to_type" or something.

--Dan