Computer Architecture, Instruction Set, Intel, X86, Computer Science.
opcode byte 0FH as the first opcode byte and using specific prefixes to tell the decoder “Hey I’m a long opcode!". As if having a variable-length opcode is not complex enough, in some instructions, the opcode uses 3 bits from the ModR/M byte. Speaking of the devil, the next topic is, ModR/M Byte >