AESENC (Perform One Round of an AES Encryption Flow)

Opcodes

Opcode/Instruction Op/En 64/32-bit Mode CPUID Feature Flag Description
66 0F 38 DC /r AESENC xmm1, xmm2/m128 RM V/V AES Perform one round of an AES encryption flow, operating on a 128-bit data (state) from xmm1 with a 128-bit round key from xmm2/m128.
VEX.NDS.128.66.0F38.WIG DC /r VAESENC xmm1, xmm2, xmm3/m128 RVM V/V Both AES and AVX flags Perform one round of an AES encryption flow, operating on a 128-bit data (state) from xmm2 with a 128-bit round key from the xmm3/m128; store the result in xmm1.

Instruction Operand Encoding

Op/En Operand 1 Operand2 Operand3 Operand4
RM ModRM:reg (r, w) ModRM:r/m (r) NA NA
RVM ModRM:reg (w) VEX.vvvv (r) ModRM:r/m (r) NA

Description

This instruction performs a single round of an AES encryption flow using a round key from the second source operand, operating on 128-bit data (state) from the first source operand, and store the result in the destination operand.

Use the AESENC instruction for all but the last encryption rounds. For the last encryption round, use the AESENC-CLAST instruction.

128-bit Legacy SSE version: The first source operand and the destination operand are the same and must be an XMM register. The second source operand can be an XMM register or a 128-bit memory location. Bits (VLMAX-1:128) of the corresponding YMM destination register remain unchanged.

VEX.128 encoded version: The first source operand and the destination operand are XMM registers. The second source operand can be an XMM register or a 128-bit memory location. Bits (VLMAX-1:128) of the destination YMM register are zeroed.

Operation

AESENC

STATE ← SRC1;
RoundKey ← SRC2;
STATE ← ShiftRows( STATE );
STATE ← SubBytes( STATE );
STATE ← MixColumns( STATE );
DEST[127:0] ← STATE XOR RoundKey;
DEST[VLMAX-1:128] (Unmodified)

VAESENC

STATE ← SRC1;
RoundKey ← SRC2;
STATE ← ShiftRows( STATE );
STATE ← SubBytes( STATE );
STATE ← MixColumns( STATE );
DEST[127:0] ← STATE XOR RoundKey;
DEST[VLMAX-1:128] ← 0

Intel C/C++ Compiler Intrinsic Equivalent

(V)AESENC:

__m128i _mm_aesenc (__m128i, __m128i)

SIMD Floating-Point Exceptions

None

Other Exceptions

See Exceptions Type 4.