Intel® Architecture Instruction Set Extensions Programming Reference

PXOR — Exclusive Or
Opcode/
Instruction
Description
Instruction Operand Encoding
INSTRUCTION SET REFERENCE
Performs a bitwise logical XOR operation on the second source operand and the first source operand and stores the
result in the destination operand. Each bit of the result is set to 1 if the corresponding bits of the first and second
operands differ, otherwise it is set to 0.
Legacy SSE instructions: In 64-bit mode using a REX prefix in the form of REX.R permits this instruction to access
additional registers (XMM8-XMM15).
128-bit Legacy SSE version: The second source operand is an XMM register or a 128-bit memory location. The first
source operand and destination operands are XMM registers. Bits (255:128) of the corresponding YMM destination
register remain unchanged.
VEX.128 encoded version: The second source operand is an XMM register or a 128-bit memory location. The first
source operand and destination operands are XMM registers. Bits (127:128) of the corresponding YMM register are
zeroed.
VEX.256 encoded version: The second source operand is an YMM register or a 256-bit memory location. The first
source operand and destination operands are YMM registers.
Operation
VPXOR (VEX.256 encoded version)
DEST SRC1 XOR SRC2
VPXOR (VEX.128 encoded version)
DEST SRC1 XOR SRC2
DEST[VLMAX:128] 0
PXOR (128-bit Legacy SSE version)
DEST DEST XOR SRC
DEST[VLMAX:128] (Unmodified)
Op/
En
Intel C/C++ Compiler Intrinsic Equivalent
64/3
2-bit
Mode
CPUID
Feature
Flag
(V)PXOR: __m128i _mm_xor_si128 ( __m128i a, __m128i b)
VPXOR: __m256i _mm256_xor_si256 ( __m256i a, __m256i b)
Description
66 0F EF /r A V/V SSE2 Bitwise XOR of xmm2/m128 and xmm1.
PXOR xmm1, xmm2/m128
VEX.NDS.128.66.0F.WIG EF /r B V/V AVX Bitwise XOR of xmm3/m128 and xmm2.
VPXOR xmm1, xmm2, xmm3/m128
VEX.NDS.256.66.0F.WIG EF /r B V/V AVX2 Bitwise XOR of ymm3/m256 and ymm2.
VPXOR ymm1, ymm2, ymm3/m256
Op/En Operand 1 Operand 2 Operand 3 Operand 4
A ModRM:reg (r, w) ModRM:r/m (r) NA NA
B ModRM:reg (w) VEX.vvvv ModRM:r/m (r) NA
Ref. # 319433-014 5-171