sm3tt2a

SM3 Step 3A (A32)

SM3TT2A.32 <Qd>, <Dn>, <Dm>, #<imm>

SM3 cryptographic hash step 3A.

Pseudocode Operation

Qd ← SM3_TT2A(Dn, Dm, imm2)

Example

SM3TT2A.32 q0, d1, d2, #16

Encoding

Binary Layout

11001110010

31:21

20:16

15:14

imm2

13:12

11:10

9:5

4:0

Format Crypto Imm

Opcode 0xCE408800

Extension Crypto (SM3)

Operands

Qd
Destination 128-bit SIMD register
Dn
First source 64-bit SIMD/FP register
Dm
Second source 64-bit SIMD/FP register
imm
Rot

Reference

View in Arm A64 ISA Reference ↗ Arm A64 ISA

Instruction Forms

Encoding	Instruction		ISA		Bit pattern
0xCE408800	SM3TT2A <Vd>.4S, <Vn>.4S, <Vm>.S[<imm2>]		A64		11001110010 \| Rm \| 10 \| imm2 \| 10 \| Rn \| Rd

Description

SM3TT2A takes three 128-bit vectors from three source SIMD&FP register and a 2-bit immediate index value, and returns a 128-bit result in the destination SIMD&FP register. It performs a three-way exclusive-OR of the three 32-bit fields held in the upper three elements of the first source vector, and adds the resulting 32-bit value and the following three other 32-bit values: A three-way exclusive-OR is performed of the result of this addition, the result of the addition rotated left by 9, and the result of the addition rotated left by 17. The result of this exclusive-OR is returned as the top element of the returned result. The other elements of this result are taken from elements of the first source vector, with the element returned in bits<63:32> being rotated left by 19. This instruction is implemented only when FEAT_SM3 is implemented.

Operation

AArch64.CheckFPAdvSIMDEnabled();

bits(128) Vm = V[m, 128];
bits(128) Vn = V[n, 128];
bits(128) Vd = V[d, 128];
bits(32) Wj;
bits(128) result;
bits(32) TT2;

Wj = Elem[Vm, i, 32];
TT2 = Vd<63:32> EOR (Vd<127:96> EOR Vd<95:64>);
TT2 = (TT2+Vd<31:0>+Vn<127:96>+Wj)<31:0>;

result<31:0> = Vd<63:32>;
result<63:32> = ROL(Vd<95:64>, 19);
result<95:64> = Vd<127:96>;
result<127:96> = TT2 EOR ROL(TT2, 9) EOR ROL(TT2, 17);
V[d, 128] = result;