[PATCH 00/10] RISC-V: Refactor instructions

[Charlie Jenkins <charlie@rivosinc.com>]

On Fri, Aug 18, 2023 at 09:30:32AM +0200, Andrew Jones wrote:
> On Thu, Aug 17, 2023 at 10:52:22AM -0700, Palmer Dabbelt wrote:
> > On Thu, 17 Aug 2023 09:43:16 PDT (-0700), Charlie Jenkins wrote:
> ...
> > > It seems to me that it will be significantly more challenging to use
> > > riscv-opcodes than it would for people to just hand create the macros
> > > that they need.
> > 
> > Ya, riscv-opcodes is pretty custy.  We stopped using it elsewhere ages ago.
> 
> Ah, pity I didn't know the history of it or I wouldn't have suggested it,
> wasting Charlie's time (sorry, Charlie!). So everywhere that needs
> encodings are manually scraping them from the PDFs? Or maybe we can write
> our own parser which converts adoc/wavedrom files[1] to Linux C?
> 
> [1] https://github.com/riscv/riscv-isa-manual/tree/main/src/images/wavedrom

The problem with the wavedrom files is that there are no standard for
how each instruction is identified. The title of of the adoc gives some
insight and there is generally a funct3 or specific opcode that is
associated with the instruction but it would be kind of messy to write a
script to parse that. I think manually constructing the instructions is
fine. When somebody wants to add a new instruction they probably will
not need to add very many at a time, so it should be only a couple of
lines that they will be able to test.

> 
> Thanks,
> drew