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Source code

SHA256MSG2

Perform a Final Calculation for the Next Four SHA256 Message Dwords

stableVMJITAOTinstruction

Encodings

OpcodeInstructionOp/En64-bitCompat/LegacyDescription
NP 0F 38 CD /rSHA256MSG2 xmm1, xmm2/m128RMValidValidPerforms the final calculation for the next four SHA256 message dwords using previous message dwords from xmm1 and xmm2/m128, storing the result in xmm1.

Operand encoding

Each mode is a value of the Op/En column above. It says which field of the encoded instruction carries each operand, in the order they are written, and whether the instruction reads it, writes it or both.

RM

  1. modrm.reg lectura y escrituraModRM byte, reg field (bits 5-3)
  2. modrm.rm lecturaModRM byte, r/m field (bits 2-0); with the SIB byte and the displacement when the mod field asks for them

Measured cost

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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] + 1( W14) ;
W17 := SRC1[63: 32] + 1( W15) ;
W18 := SRC1[95: 64] + 1( W16) ;
W19 := SRC1[127: 96] + 1( W17) ;

DEST[127:96] := W19 ;
DEST[95:64] := W18 ;
DEST[63:32] := W17 ;
DEST[31:0] := W16;

Intel C/C++ compiler intrinsics

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."

Sources