x86doc › SHA256MSG1 - Perform an Intermediate Calculation for the Next Four SHA256 Message Dwords

SHA256MSG1—Perform an Intermediate Calculation for the Next Four SHA256 Message Dwords

Opcode/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
NP 0F 38 CC /r SHA256MSG1 xmm1, xmm2/m128	RM	V/V	SHA	Performs an intermediate 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 SHA256MSG1 instruction is one of two SHA256 message scheduling instructions. The instruction performs an intermediate calculation for the next four SHA256 message dwords.

Operation

SHA256MSG1

W4 := SRC2[31: 0] ;
W3 := SRC1[127:96] ;
W2 := SRC1[95:64] ;
W1 := SRC1[63: 32] ;
W0 := SRC1[31: 0] ;
DEST[127:96] := W3 + σ0( W4);
DEST[95:64] := W2 + σ0( W3);
DEST[63:32] := W1 + σ0( W2);
DEST[31:0] := W0 + σ0( W1);

Intel C/C++ Compiler Intrinsic Equivalent

SHA256MSG1 __m128i _mm_sha256msg1_epu32(__m128i, __m128i);

Flags Affected

None.

SIMD Floating-Point Exceptions

None.

Other Exceptions

See Table 2-21, “Type 4 Class Exception Conditions.”