Patch to add builtin strncmp and builtin strncpy

[Kaveh R. Ghazi]

 > From: Jakub Jelinek <jakub@redhat.com>
 > > 
 > > Why not also
 > > 
 > > strncpy(s1, "string", n) -> memcpy (s1, "string", sizeof ("string")+1)
 > >    (where strlen("string")+1 < n)
 > 
 > Because they do different thing, strncpy has to pad it with '\0' up to
 > length n.

Exactly.

 > The transformation could be really
 > -> slen = strlen ("string") + 1;
 >    memcpy (s1, "string", slen);
 >    memset (s1 + slen, 0, n - slen);
 > 
 > but then the question is if it is really an optimization (it could be if
 > both memcpy and memset are inlined.

Is there a way to tell if memset is going to be inlined by gcc ahead
of time?  E.g. if (n-slen) < some-threshold?  I could then have the
builtin transform these cases too.  (The clear_storage() function is
gobbledygook to me.)

		--Kaveh
--
Kaveh R. Ghazi			Engagement Manager / Project Services
ghazi@caip.rutgers.edu		Qwest Internet Solutions