On Tue, 6 Apr 1999 18:41:29 -0700 (PDT) 
 Matthew Jacob <mjacob@nas.nasa.gov> wrote:

 > So just to reconfirm- for sparc64 ports __sparc__ won't be defined, but
 > __sparc64__ will be....

Note the lack of underscores in my message...

The kernel Makefiles define symbols that match $MACHINE, i.e. "sparc"
and "sparc64".  Like "hp300", "amiga", "pmax", "mac68k", etc.

        -- Jason R. Thorpe <thorpej@nas.nasa.gov>