EON (shifted register) Bitwise exclusive-OR NOT (shifted register) This instruction performs a bitwise exclusive-OR NOT between a register value and an optionally-shifted register value, and writes the result to the destination register. This instruction is a data-independent-time instruction as described in About PSTATE.DIT. 1 0 0 1 0 1 0 1 0 EON <Wd>, <Wn>, <Wm>{, <shift> #<amount>} 1 EON <Xd>, <Xn>, <Xm>{, <shift> #<amount>} if sf == '0' && imm6[5] == '1' then EndOfDecode(Decode_UNDEF); end; let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let datasize : integer{} = 32 << UInt(sf); let shift_type : ShiftType = DecodeShift(shift); let shift_amount : integer = UInt(imm6); <Wd> Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field. <Wn> Is the 32-bit name of the first general-purpose source register, encoded in the "Rn" field. <Wm> Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field. <shift> Is the optional shift to be applied to the final source, defaulting to LSL and shift <shift> 00 LSL 01 LSR 10 ASR 11 ROR <amount> For the "32-bit" variant: is the shift amount, in the range 0 to 31, defaulting to 0 and encoded in the "imm6" field. <amount> For the "64-bit" variant: is the shift amount, in the range 0 to 63, defaulting to 0 and encoded in the "imm6" field. <Xd> Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field. <Xn> Is the 64-bit name of the first general-purpose source register, encoded in the "Rn" field. <Xm> Is the 64-bit name of the second general-purpose source register, encoded in the "Rm" field. let operand1 : bits(datasize) = X{}(n); let operand2 : bits(datasize) = ShiftReg{}(m, shift_type, shift_amount); X{datasize}(d) = operand1 XOR NOT(operand2); 2026-03-26 20:27:25 2026-03_rel