Making EMACS run faster.

[William "Chops" Westfield <BILLW@SRI-AI.ARPA>]

This concerns people who are running TENEX EMACS on FOONLY or 2020
processors...

TECO currently executes code in the ACs in order to try to make
a string copy loop faster (on KA and KI processors, this was
probably a good idea).  On a KL processor with Cache memory,
this probably makes little difference.  On a Foonly computer,
and presumably on a 2020, since the technology involved is
similar, this is a VERY BAD idea.  The relevant code has been
shown to run 10 to 15 times SLOWER in the ACs of a foonly F4
than the same code run from memory.  There are technical reasons
for this, but the bottom line is that unless you have a KA or KI,
the string copy loop should be left in memory.

I have not made the actual patches.  the relevant portions of code
are near YANK3 and PCHF2

Enjoy
BillW
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