> This looks a lot like the thumb ARM thingy? Unsure what you asking? The RISC-V C extension has some vague similarities with thumb. But the Qualcomm proposed

> This looks a lot like the thumb ARM thingy? Unsure what you asking? The RISC-V C extension has some vague similarities with thumb. But the Qualcomm proposed Zics extension absolutely hasn't. Zics adds things like more advanced addressing modes, load/store pair instructions etc. that are found in the aarch64 ISA, all with 32-bit instructions. Notable that ARM didn't create any 16-bit Thumb variant of aarch64.