All instructionsx86-64Logical

PXOR

/ VPXOR

Bitwise exclusive OR

Set each result bit when the corresponding input bits differ.

SSE28-bit bits elements

Similar operations on Arm64:EORveorq_u8

Instruction forms

3 in this sample
FormBitsRequiresEncoding
PXOR xmm1, xmm2128SSE266 0F EF /r
VPXOR xmm1, xmm2, xmm3128AVXVEX.L0.66.0F.WIG EF /r
VPXOR ymm1, ymm2, ymm3256AVX2VEX.L1.66.0F.WIG EF /r
128 bits · 16 × 8-bit elements

Explore the operation

The interactive explorer is loading. The operation and reference details are available below.

Operation

Pseudo-C · selected form
dst = a XOR b

Simplified pseudocode for the selected form.

Exact upstream semantics

Standard variant

Source: intel/PXOR-Logical-Exclusive-OR.xml/0

let result := src1 xor src2;

Parameterized by register and element size; from the pinned upstream definition.

What to watch for

  • This is a bitwise operation; the byte grouping in the explorer is a display choice.

Corresponding intrinsics

C / C++ · selected form
_mm_xor_si128
__m128i _mm_xor_si128(__m128i a, __m128i b)
#include <emmintrin.h>SSE2

Documented instruction mapping; a compiler may use an equivalent encoding or optimize the operation away.

Documented mapping

PXOR xmm, xmm

Architectural details

Flags
Arithmetic flags unchanged.
Destination
Writes the low 128 bits; upper vector-register bits are preserved.
Encoding
66 0F EF /r
Operands
  • xmm1read / write · 128 bits (16 × 8)
  • xmm2read · 128 bits (16 × 8)
Coverage
Selected register-only 128/256-bit forms. Memory operands, MMX, and EVEX/AVX-512 forms are outside this sample.
Exception information & execution requirements
  • #NM
  • #UD

Feature availability alone does not guarantee execution: OS state and execution-level controls also apply. Use the linked architecture documentation for the full exception conditions.

Performance measurements are not included in this preview. Latency and throughput depend on the exact form and microarchitecture. Measured data on uops.info ↗

Sources & provenance

Technical fields are imported from pinned upstream files. Explanations and explorer behavior are maintained separately.

Intel · PXOR-Logical-Exclusive-OR.xml
Revision
4ebe7f0ac1bd00f46244c49bb72c503ce368def7
SHA-256
9537c58c38c20a921118f867c1f34fdfc26b5636773d2faafcb6145a210b2475
Terms
Intel SDM terms; see License.md
View pinned upstream file ↗
Intel · intrinsics.xml
Revision
4ebe7f0ac1bd00f46244c49bb72c503ce368def7
SHA-256
6762a50652a35ef663fd532ed83b789d19bbc2ac7e94b1771f19d666d96c2c30
Terms
Intel SDM terms; see License.md
View pinned upstream file ↗

Intel sources are a documentation preview. Arm ACLE mappings are adapted under CC BY-SA 4.0 with an additional patent license. Arm MRS encoding data is distributed under BSD-3-Clause. © Arm Limited and contributors. Coverage and attribution.