movc3 is NOT always faster!

[rbbb%rice at sri-unix.UUCP]

From:  David Chase <rbbb at rice>

Probably true, but (on a 750, 4.1 version of cc) when benchmarking a
suitably packaged movc3 against various versions of a C loop doing the
same thing, the movc3 begins to win on 20 bytes (about 2 times as fast, it
seems).  On 100 byte moves it is winning by a factor of 7.  Also, since
everyone uses CALLS or CALLG, the registers get pushed at the procedure
call.

drc