On 8/23/21 7:38 PM, Tom Stepleton via cctalk wrote:
Hello,
For the sake of illustration to folks who are not necessarily used to
thinking about what computers do at the machine code level, I'm interested
in collecting examples of single instructions for any CPU architecture that
are unusually prolific in one way or another. This request is highly
underconstrained, so I have to rely on peoples' good taste to determine
what counts as "interesting" here. Perhaps a whole lot of different kinds
of work or lots of different resources accessed is what I'm after. I expect
these kinds of "busy" instructions were more common in architectures that
are now less common, so perhaps this list is a good place to ask.
Well, you really need to look at VLIW architectures. Very
Long Instruction Word. See the Trace Multiflow for an
example. Every instruction had a load/store field, an
integer arithmetic field (for address calculations) and a
floating point field. For more money, you added boards and
there were more of these fields in the instruction. There
was no cache, the compiler moved the address calculation and
the data fetch sufficiently far up the code so the data
would be available when needed.
Jon
