Link: https://gpuopen.com/amd-isa-documentation/

AMD's ISAs are all stored here on gpuopen.com.

This is the assembly-language level reference to each of the AMD GPUs.

For the most part, the ISAs across the generations are all roughly the same. Most instructions, like add, multiply, or even permute/bpermute and such, will never change.

However, the latest ISAs from AMD include Raytracing instructions (RDNA 2+), or the 4x4 FP16 Matrix Multiplication instructions (CDNA). You'll probably never directly write this assembly language, but if you're trying to push the performance of your code to the maximum level, its important to know how the assembly-language is generally organized.

There's lots of good details into the internal organization of the WGPs (Workgroup Processors), or CUs (Compute Units) as well. Just a "Good to know" sorta thing for improving your mental model of how these GPUs actually function under the hood.