On Jul 29, 2014, at 12:13 PM, Chuck Guzis <cclist at sydex.com> wrote:
Which brings up an interesting question--how many
other machines shrunk
their instruction set during the course of evolution, rather
than the other
The MC68060 shed a number of integer mul/div, FP transendentals, and some
variants of conditional MOVE instructions that the MC68040 implemented, as
well as some privileged mode instructions like PTEST. I'm sure there are
others I've forgotten. Motorola provided exception handling software that
would emulate (many) of the unimplemented instructions.
MicroVAX dropped BCD instructions. So, I think, did x86_64.