I&#x27;d argue most SIMD hardware instruction sets do support that.  x86 has had pshufb since SSSE3 (most desktop+laptop, and ~all mobile x86), providing an arbitrary byte shuffle across 16 bytes, and NEON has vtbl, pretty much the same but limited to 8 bytes of output per instruction.<p>Now, I will admit that those instructions are not always a good idea (particularly on mobile x86, where pshufb is often several cycles), and they&#x27;re essentially never a good idea when a specialized instruction (e.g. punpcklbw, vtrn) can do the job.