SM4EKEY SM4 key This instruction takes an input as a 128-bit vector from the first source SIMD&FP register and a 128-bit constant from the second SIMD&FP register. It derives four iterations of the output key, in accordance with the SM4 standard, returning the 128-bit result to the destination SIMD&FP 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 1 0 0 1 1 1 0 0 1 1 1 1 0 0 1 0 SM4EKEY <Vd>.4S, <Vn>.4S, <Vm>.4S if !IsFeatureImplemented(FEAT_SM4) then UNDEFINED; constant integer d = UInt(Rd); constant integer n = UInt(Rn); constant integer m = UInt(Rm); <Vd> Is the name of the SIMD&FP destination register, encoded in the "Rd" field. <Vn> Is the name of the first SIMD&FP source register, encoded in the "Rn" field. <Vm> Is the name of the second SIMD&FP source register, encoded in the "Rm" field. AArch64.CheckFPAdvSIMDEnabled(); constant bits(128) Vm = V[m, 128]; bits(32) intval; bits(32) const; bits(128) roundresult; roundresult = V[n, 128]; for index = 0 to 3 const = Elem[Vm, index, 32]; intval = roundresult<127:96> EOR roundresult<95:64> EOR roundresult<63:32> EOR const; for i = 0 to 3 Elem[intval, i, 8] = Sbox(Elem[intval, i, 8]); intval = intval EOR ROL(intval, 13) EOR ROL(intval, 23); intval = intval EOR roundresult<31:0>; roundresult<31:0> = roundresult<63:32>; roundresult<63:32> = roundresult<95:64>; roundresult<95:64> = roundresult<127:96>; roundresult<127:96> = intval; V[d, 128] = roundresult;