SHA1MSG2 — Perform a Final Calculation for the Next Four SHA1 Message Dwords

Opcode/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
NP 0F 38 CA /r SHA1MSG2 xmm1, xmm2/m128	RM	V/V	SHA	Performs the final calculation for the next four SHA1 message dwords using intermediate results from xmm1 and the previous message dwords from xmm2/m128, storing the result in xmm1.

Instruction Operand Encoding ¶

Op/En	Operand 1	Operand 2	Operand 3
RM	ModRM:reg (r, w)	ModRM:r/m (r)	NA

Description ¶

The SHA1MSG2 instruction is one of two SHA1 message scheduling instructions. The instruction performs the final calculation to derive the next four SHA1 message dwords.

Operation ¶

SHA1MSG2 ¶

W13←SRC2[95:64] ;
W14←SRC2[63: 32] ;
W15←SRC2[31: 0] ;
W16←(SRC1[127:96] XOR W13 ) ROL 1;
W17←(SRC1[95:64] XOR W14) ROL 1;
W18←(SRC1[63: 32] XOR W15) ROL 1;
W19←(SRC1[31: 0] XOR W16) ROL 1;
DEST[127:96] ← W16;
DEST[95:64] ← W17;
DEST[63:32] ← W18;
DEST[31:0] ← W19;

Intel C/C++ Compiler Intrinsic Equivalent ¶

SHA1MSG2: __m128i _mm_sha1msg2_epu32(__m128i, __m128i);

Flags Affected ¶

None

SIMD Floating-Point Exceptions ¶

None

Other Exceptions ¶

See Exceptions Type 4.