Addressing Criticism of RISC-V Microprocessors

Is RISC-V just a rehash of 1980s RISC ideas? Requires too many instructions to do simple stuff?

RISC-V is an instruction-set architecture (ISA) for microprocessors which people seem to either love or hate. In particular there seem to bit of rivalry between the ARM and RISC-V camp developing.

It is perhaps not without reason. RISC-V and ARM represent quite radically different philosophies about how a RISC chip should be designed. RISC-V is taking a very long term view with a strong emphasis on simplicity and not painting yourself into a corner due to choices which have short term benefit, but may cause long term problems. RISC-V really embrace the philosophy of RISC, in terms of keeping things really simple with not only a minimal instruction-set but also one dominated by simple instructions.

ARM is more of a ruthlessly pragmatic design choice. Choices are made based on what makes sense today and in the near future in terms of what we are currently capable of doing in hardware. ARM design does not shy away from adding fairly complex instructions if those are believed to improve overall performance.

Hence ARM has numerous instructions which each do quite a lot of work. ARM has instructions for complex addressing modes as well as…