CNT Count bits This instruction counts the number of binary one bits in the value of the source register, 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. 1 0 1 1 0 1 0 1 1 0 0 0 0 0 0 0 0 0 1 1 1 0 CNT <Wd>, <Wn> 1 CNT <Xd>, <Xn> if !IsFeatureImplemented(FEAT_CSSC) then UNDEFINED; constant integer datasize = 32 << UInt(sf); constant integer d = UInt(Rd); constant integer n = UInt(Rn); <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 general-purpose source register, encoded in the "Rn" 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 general-purpose source register, encoded in the "Rn" field. constant bits(datasize) operand1 = X[n, datasize]; constant integer result = BitCount(operand1); X[d, datasize] = result<datasize-1:0>;