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. This instruction is a data-independent-time instruction as described in About PSTATE.DIT. 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 EndOfDecode(Decode_UNDEF); end; let datasize : integer{} = 32 << UInt(sf); let d : integer{} = UInt(Rd); let n : integer{} = 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. let operand1 : bits(datasize) = X{}(n); let result : integer = BitCount(operand1); X{datasize}(d) = result[datasize-1:0]; 2026-03-12 12:23:09 2025-09_rel_asl1