M

Size in bytes of each instruction. 0 means illegal instruction. bit M: if there is a modregrm field (EV1 is reserved for modregrm) bit T: if there is a second operand (EV2) bit E: if second operand is only 8 bits bit A: a short version exists for the AX reg bit R: a short version exists for regs bits 2..0: size of instruction (excluding optional bytes)

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