Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

## SM4EKEY

SM4 Key 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.

This instruction is implemented only when FEAT_SM4 is implemented.

### Advanced SIMD
(FEAT_SM4)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
1 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | Rm | 1 | 1 | 0 | 0 | 1 | 0 | Rn | Rd

####

SM4EKEY <Vd>.4S, <Vn>.4S, <Vm>.4S

if !HaveSM4Ext() then UNDEFINED; integer d = UInt(Rd); integer n = UInt(Rn); integer m = UInt(Rm);

### Assembler Symbols

<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.

### Operation

AArch64.CheckFPAdvSIMDEnabled(); 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;

### Operational information

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.

Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

Internal version only: isa v33.64, AdvSIMD v29.12, pseudocode v2023-06_rel, sve v2023-06_rel ; Build timestamp: 2023-07-04T19:42

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