48/64 bit instructions

[drom]

Awesome project! I am trying to add custom SIMD instructions. Is it possible to add 48 / 64 bit instructions? Can iBus_rsp_inst bus be extended to 64 / 128?

[Dolu1990]

Hi It would mainly require some upgrades on the program counter managment, instruction fetch and instruction decode. Nothing impossible, but would need some works.

I would say for this kind of upgrade the best is to start by patching the uncached instruction implementation to keep things simple (Not the cached one)

[Dolu1990]

It isn't 48/64 bits. but there is a working RV32IMC in the reworkFetcher branch. All the fetching architecture was reworked, as it was the main obstacle to variable width instruction encoding.