x86-64.net

Instruction

CLFLUSHOPT

Writes back and invalidates the cache line holding a byte of memory like CLFLUSH, but unordered with flushes of other lines, so several can overlap.

Extensions
Forms
1 (1 Legacy)
Data
Intel XED v2026.08.23

Forms

Every encoding of CLFLUSHOPT that Intel XED knows, one row per XED instruction form (iform). How to read the notation.
InstructionEncodingRequires
CLFLUSHOPT m8 CLFLUSHOPT_MEMmprefetch66 0F AE /7CLFLUSHOPT

Intrinsics

The C intrinsics of Clang 23.1.2 that compile to CLFLUSHOPT, each with the form it compiles to and the Clang options it needs. The forms come from compiling every intrinsic and decoding the result with Intel XED; all intrinsics A–Z explains the method.

IntrinsicCompiles to
_mm_clflushopt void _mm_clflushopt(const void *__m)

CLFLUSHOPT m8 Legacy -mclflushopt

CPUID and processors

Each form belongs to an XED ISA set. A form can be used when the processor reports every CPUID bit of one of its ISA set's alternatives.

CPUID requirements and processors of the XED ISA sets above. Alternatives are separated by “or”; processors follow XED’s chip model, which covers AMD processors up to Zen 2.
ISA setCPUIDProcessors in XED
CLFLUSHOPT

CLFLUSHOPT
CPUID.(EAX=07H,ECX=0):EBX[23] CLFLUSHOPT

Skylake, Comet Lake, Cannon Lake, Ice Lake (client), Tiger Lake, Alder Lake, Arrow Lake, Panther Lake, Nova Lake, Skylake-SP, Cascade Lake, Cooper Lake, Ice Lake (server), Sapphire Rapids, Emerald Rapids, Granite Rapids, Diamond Rapids, Goldmont, Goldmont Plus, Tremont, Snow Ridge, Lakefield, Sierra Forest, Clearwater Forest, Zen, Zen+, Zen 2

Sources

  1. Intel XED v2026.08.23 (commit 0bcb6237345c): forms, encodings, ISA sets, CPUID bits and chip model.
  2. Clang's x86 intrinsic headers, LLVM 23.1.2 (commit 85ac56026243): the intrinsics, their signatures and doc comments, and the Clang of that release, which compiled each of them.
  3. Intel 64 and IA-32 Architectures Software Developer's Manual, Volume 2 (325383-092, June 2026)

The tables are derived from Intel XED, Copyright Intel Corporation, licensed under the Apache License 2.0; x86-64.net converted and reformatted them. The intrinsics and their signatures come from Clang, part of the LLVM Project, licensed under the Apache License 2.0 with LLVM Exceptions. The text is our own.