This table identifies operations for the instruction groups which contain
the opcode in bits 3-5 of the second byte (normally the addressing mode
byte).
md000rm md001rm md010rm md011rm md100rm md101rm md110rm md111rm
ArOp1 ADD OR ADC SBB AND SUB XOR CMP
ArOp2 ADD ADC SBB SUB CMP
ShftOp ROL ROR RCL RCR SHL/SAL SHR RAR
Grp1 TEST NOT NEG MUL IMUL DIV IDIV
Grp2 INC DEC CALL nr CALL fr JMP nr JMP far PUSH
Grp3 INC DEC