BCOPY and Hardware Hacking
Alan Lehotsky
alan at apollo.UUCP
Sat Oct 15 04:55:27 AEST 1983
Concerning the suggested change
> In the VAX bcopy function posted, it would probably be faster if the
> constant 65535 was replaced by 65532 wherever it occurs, thus causing
> all memory references to be longword references if the source and destination
> are longword-aligned.
I'm fairly certain that the micro-code for VAXEN already does this
for you. As a former DIGIT (DEC employee), I know that a lot of work
was done to make string moves as fast as possible, and all sorts of
tricks such as getting to quad-word alignment and doing double-bus transfers
over the SBI. [I don't have my hardware manuals handy, so....]
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