UMAX (register) Unsigned maximum (register) This instruction determines the unsigned maximum of the two source register values 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 1 1 0 1 0 1 1 0 0 1 1 0 0 1 0 UMAX <Wd>, <Wn>, <Wm> 1 UMAX <Xd>, <Xn>, <Xm> if !IsFeatureImplemented(FEAT_CSSC) then UNDEFINED; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); constant integer datasize = 32 << UInt(sf); <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. <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 = X[m, datasize]; constant integer result = Max(UInt(operand1), UInt(operand2)); X[d, datasize] = result<datasize-1:0>;