[abc80] abc80sim 3.1 amusement

[H. Peter Anvin]

So I ran a simple timing loop program on abc80sim 3.1.

I found that on my system, it can run extremely cycle-accurate up to
about 120 MHz. After that point, the frequency starts to vary
noticeably; not surprisingly more and more as the target frequency
increases.  With --speed max my laptop runs at about 420 MHz, but it
varies with as much as 30 MHz from one measurement to the next. This
isn't very strange, since at that point there isn't any direct
connection between the execution time and real time at all.

	-hpa