ADD (shifted register) Add (shifted register) This instruction adds a register value and an optionally-shifted register value, and writes the result to the destination register. If PSTATE.DIT is 1: The execution time of this instruction is independent of: The values of the data supplied in any of its registers. The values of the NZCV flags. The response of this instruction to asynchronous exceptions does not vary based on: The values of the data supplied in any of its registers. The values of the NZCV flags. 0 0 0 1 0 1 1 0 0 ADD <Wd>, <Wn>, <Wm>{, <shift> #<amount>} 1 ADD <Xd>, <Xn>, <Xm>{, <shift> #<amount>} if shift == '11' then UNDEFINED; if sf == '0' && imm6<5> == '1' then UNDEFINED; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); constant ShiftType shift_type = DecodeShift(shift); constant integer shift_amount = 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 type to be applied to the second source operand, defaulting to LSL and shift <shift> 00 LSL 01 LSR 10 ASR 11 RESERVED <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. constant bits(datasize) operand1 = X[n, datasize]; constant bits(datasize) operand2 = ShiftReg(m, shift_type, shift_amount, datasize); bits(datasize) result; (result, -) = AddWithCarry(operand1, operand2, '0'); X[d, datasize] = result;