alias analysis

[Robert Dewar]

> Umar Janjua wrote:
> 
>> What kind of alias analysis is performed by GCC.

Note that in Ada (GNAT), we get much more accurate alias
information from the nature of the language, because of its
strong typing. For instance, two separate integer types in
Ada:

     type A is new Integer;
     type B is new Integer;

will be in separate alias sets. It's tricky to get the
mapping correct, but as far as we know it is correct
(and quite precise) in the latest version of checked
in sources for GNAT and gigi.