Re:Apple’s new M1 Pro and M1 Max processors
by chasil on Monday October 18, 2021 @08:35PM
(#28913619)
If its got microcode, it's not RISC.
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Re:Apple’s new M1 Pro and M1 Max processors
by dragontamer on Monday October 18, 2021 @08:41PM
(#28913654)
POWER9, RISC-V, and ARM all have microcoded instructions. In particular, division, which is very complicated.
As all CPUs have decided that hardware-accelerated division is a good idea (and in particular: microcoded, single-instruction division makes more sense than spending a bunch of L1 cache on a series of instructions that everyone knows is "just division" and/or "modulo"), microcode just makes sense.
The "/" and "%" operators are just expected on any general purpose CPU these days.
30 years ago, RISC processors didn't implement divide or modulo. Today, all processors, even the "RISC" ones, implement it.