AESD AES single round decryption The AESD instruction reads a 16-byte state array from each 128-bit segment of the first source vector, together with a round key from the corresponding 128-bit segment of the second source vector. Each state array undergoes a single round of the AddRoundKey(), InvSubBytes() and InvShiftRows() transformations in accordance with the AES standard. Each updated state array is destructively placed in the corresponding segment of the first source vector. This instruction is unpredicated. ID_AA64ZFR0_EL1.AES indicates whether this instruction is implemented. This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled. Green False True SM_0_only 0 1 0 0 0 1 0 1 0 0 1 0 0 0 1 0 1 1 1 0 0 1 AESD <Zdn>.B, <Zdn>.B, <Zm>.B if !IsFeatureImplemented(FEAT_SVE) || !IsFeatureImplemented(FEAT_SVE_AES) then UNDEFINED; constant integer m = UInt(Zm); constant integer dn = UInt(Zdn); <Zdn> Is the name of the first source and destination scalable vector register, encoded in the "Zdn" field. <Zm> Is the name of the second source scalable vector register, encoded in the "Zm" field. CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer segments = VL DIV 128; constant bits(VL) operand1 = Z[dn, VL]; constant bits(VL) operand2 = Z[m, VL]; bits(VL) result; result = operand1 EOR operand2; for s = 0 to segments-1 Elem[result, s, 128] = AESInvSubBytes(AESInvShiftRows(Elem[result, s, 128])); Z[dn, VL] = result;