3 ms·
> It seems they are trying to slap a riscv decoder with a minimum amount of work. This doesn’t make sense to me. I thought that one of the selling points of th
by klelatti 3y ago
> It seems they are trying to slap a riscv decoder with a minimum amount of work.
This doesn’t make sense to me. I thought that one of the selling points of the C extension was that it was a minimal amount of work to add to the decoder.
- monocasa 3y agoIt is a minimal amount of work to add to a decoder... if you start with it in your design from day one. The actual decoding is trivial, but if your front end is designed around aligned instructions, there's potentially some nontrivial work on high end cores around correct handling of goofy states like when non aligned instructions straddle cache lines or pages. Definitely doable, but it felt like Qualcomm was trying as much as possible to just change out the 'pure function which turns instruction bit patterns into micro-op bit patterns' part of the decoder.