C builtin functions?

[KW Heuer]

In article <1224 at ulysses.UUCP> ulysses!jss (Jerry Schwarz) writes:
>>Indeed, X3J11 has decreed that there must be an actual
>>extern definition of each required function....
>
>There may have been a recent change of heart, but the Feb 86 draft
>stated (D.1.2):
>
>        All external identifiers declared in any of the  headers
>        [enumerated in the standard] are reserved, whether or not
>        the associated header is included. ...

This is not necessarily a contradiction; even if strcpy *IS* compiled
into a single instruction, there must *ALSO* be a copy in the library
so you can take its address.

I'm all for optimization, but having the functions built-in disturbs
me a little.  There are applications that have to run stand-alone;
e.g. the UNIX* kernel (which has some functions of its own with names
identical to those in libc).  Will these have to be renamed to conform
to the standard?  Perhaps there should be a compiler option to inhibit
expansion of builtins?

Actually, it seems to me that the correct way to handle it is with an
optimizing *loader*.  When the loader detects a call to strcpy, and
sees that strcpy in libc is small, it could do the inline expansion.
Yes, I realize that this requires more information (and smarts) than
today's loader has available, but just wait...

Karl W. Z. Heuer (ihnp4!bentley!kwh), The Walking Lint
*UNIX is a trademark of AT&T Bell Laboratories