SM4EKEY

SM4 key updates

The SM4EKEY instruction reads four rounds of 32-bit input key values from each 128-bit segment of the first source vector, along with four rounds of 32-bit constants from the corresponding 128-bit segment of the second source vector. The four rounds of output key values are derived in accordance with the SM4 standard, and placed in the corresponding segments of the destination vector. This instruction is unpredicated.

ID_AA64ZFR0_EL1.SM4 indicates whether this instruction is implemented.

This instruction is illegal when executed in Streaming SVE mode, unless FEAT_SME_FA64 is implemented and enabled.

SVE2
(FEAT_SVE_SM4)

313029282726252423222120191817161514131211109876543210
01000101001Zm111100ZnZd
size<1>size<0>

SM4EKEY <Zd>.S, <Zn>.S, <Zm>.S

if !IsFeatureImplemented(FEAT_SVE) || !IsFeatureImplemented(FEAT_SVE_SM4) then UNDEFINED; constant integer n = UInt(Zn); constant integer m = UInt(Zm); constant integer d = UInt(Zd);

Assembler Symbols

<Zd>

Is the name of the destination scalable vector register, encoded in the "Zd" field.

<Zn>

Is the name of the first source scalable vector register, encoded in the "Zn" field.

<Zm>

Is the name of the second source scalable vector register, encoded in the "Zm" field.

Operation

CheckNonStreamingSVEEnabled(); constant integer VL = CurrentVL; constant integer segments = VL DIV 128; constant bits(VL) operand1 = Z[n, VL]; constant bits(VL) operand2 = Z[m, VL]; bits(VL) result; for s = 0 to segments-1 constant bits(128) source = Elem[operand2, s, 128]; bits(32) intval; bits(32) const; bits(128) roundresult = Elem[operand1, s, 128]; for index = 0 to 3 const = Elem[source, 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; Elem[result, s, 128] = roundresult; Z[d, VL] = result;

Operational information

If PSTATE.DIT is 1:


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

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