Yet more trash about strcpy and strlen on various micros

Henry Spencer henry at utzoo.UUCP
Sat Mar 16 04:29:56 AEST 1985


>      Two things from this survey surprised me, one,  that  the iAPX-286
> makes  very  good  use of clock cycles...

Well, it is the third time Intel has implemented the 86 architecture,
so they've had a chance to learn from their botches...

> ... and two, that the 32032 and the
> 32016 have such amazingly  slow  micro-code  for  a  single  instruction
> string move or scan (MOVSB U and SKPSB).

The word is not "amazingly" but "disgustingly".  When I asked him about
it point-blank (after studying the timing numbers in the 32016 manual)
my National rep admitted that the string instructions are actually
slower than tightly-coded multi-instruction sequences!!!  Try it without
the string instructions, preferably with some degree of loop unrolling.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry



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