FWIW, the original ARM CPU from 1985 (which was a very 'pure' RISC implementation) already could execute each instruction conditionally, the condition bit mask

FWIW, the original ARM CPU from 1985 (which was a very 'pure' RISC implementation) already could execute each instruction conditionally, the condition bit mask was just part of the regular opcode structure: https://en.wikichip.org/wiki/arm/armv1 https://en.wikichip.org/wiki/arm/armv1