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- December 2023
SHA256MSG2 — Perform a Final Calculation for the Next Four SHA256 Message Dwords
Opcode/Instruction | Op/En | 64/32 bit Mode Support | CPUID Feature Flag | Description |
---|---|---|---|---|
NP 0F 38 CD /r SHA256MSG2 xmm1, xmm2/m128 | RM | V/V | SHA | Performs the final calculation for the next four SHA256 message dwords using previous message dwords from xmm1 and 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) | N/A |
Description ¶
The SHA256MSG2 instruction is one of two SHA2 message scheduling instructions. The instruction performs the final calculation for the next four SHA256 message dwords.
Operation ¶
SHA256MSG2 ¶
W14 := SRC2[95:64] ; W15 := SRC2[127:96] ; W16 := SRC1[31: 0] + σ1( W14) ; W17 := SRC1[63: 32] + σ1( W15) ; W18 := SRC1[95: 64] + σ1( W16) ; W19 := SRC1[127: 96] + σ1( W17) ; DEST[127:96] := W19 ; DEST[95:64] := W18 ; DEST[63:32] := W17 ; DEST[31:0] := W16;
Intel C/C++ Compiler Intrinsic Equivalent ¶
SHA256MSG2 __m128i _mm_sha256msg2_epu32(__m128i, __m128i);
Flags Affected ¶
None.
SIMD Floating-Point Exceptions ¶
None.
Other Exceptions ¶
See Table 2-21, “Type 4 Class Exception Conditions.”