Agreed -- you can get large code size wins. This would require actively managing the instruction set so that the most common instructions are shortest. In theor

Agreed -- you can get large code size wins. This would require actively managing the instruction set so that the most common instructions are shortest. In theory, this could be done. However, this doesn't work for a legacy architecture like x86, because many of the short opcodes are no longer the commonly used ones. Some are even actively deprecated. So overall, ARM wins in code size. I'm not sure about x86/64, maybe it is better there...