x86-64.net

Instruction

VPTESTMB

Sets a mask bit for each pair of bytes whose AND is not zero.

Extensions
Forms
6 (6 EVEX)
Data
Intel XED v2026.08.23

Forms

Every encoding of VPTESTMB that Intel XED knows, one row per XED instruction form (iform). How to read the notation.
InstructionEncodingRequires
VPTESTMB k {k}, xmm, xmm VPTESTMB_MASKmskw_MASKmskw_XMMu8_XMMu8_AVX512EVEX.128.66.0F38.W0 26 /rAVX10.1 or AVX512BW + AVX512VL
VPTESTMB k {k}, xmm, m128 VPTESTMB_MASKmskw_MASKmskw_XMMu8_MEMu8_AVX512EVEX.128.66.0F38.W0 26 /rAVX10.1 or AVX512BW + AVX512VL
VPTESTMB k {k}, ymm, ymm VPTESTMB_MASKmskw_MASKmskw_YMMu8_YMMu8_AVX512EVEX.256.66.0F38.W0 26 /rAVX10.1 or AVX512BW + AVX512VL
VPTESTMB k {k}, ymm, m256 VPTESTMB_MASKmskw_MASKmskw_YMMu8_MEMu8_AVX512EVEX.256.66.0F38.W0 26 /rAVX10.1 or AVX512BW + AVX512VL
VPTESTMB k {k}, zmm, zmm VPTESTMB_MASKmskw_MASKmskw_ZMMu8_ZMMu8_AVX512EVEX.512.66.0F38.W0 26 /rAVX10.1 or AVX512BW
VPTESTMB k {k}, zmm, m512 VPTESTMB_MASKmskw_MASKmskw_ZMMu8_MEMu8_AVX512EVEX.512.66.0F38.W0 26 /rAVX10.1 or AVX512BW

Intrinsics

The C intrinsics of Clang 23.1.2 that compile to VPTESTMB, 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_test_epi8_mask __mmask16 _mm_test_epi8_mask(__m128i __A, __m128i __B)

VPTESTMB k, xmm, xmm EVEX.128 -mavx512vl -mavx512bw

_mm_mask_test_epi8_mask __mmask16 _mm_mask_test_epi8_mask(__mmask16 __U, __m128i __A, __m128i __B)

VPTESTMB k, xmm, xmm EVEX.128 -mavx512vl -mavx512bw

_mm256_test_epi8_mask __mmask32 _mm256_test_epi8_mask(__m256i __A, __m256i __B)

VPTESTMB k, ymm, ymm EVEX.256 -mavx512vl -mavx512bw

_mm256_mask_test_epi8_mask __mmask32 _mm256_mask_test_epi8_mask(__mmask32 __U, __m256i __A, __m256i __B)

VPTESTMB k, ymm, ymm EVEX.256 -mavx512vl -mavx512bw

_mm512_test_epi8_mask __mmask64 _mm512_test_epi8_mask(__m512i __A, __m512i __B)

VPTESTMB k, zmm, zmm EVEX.512 -mavx512bw

_mm512_mask_test_epi8_mask __mmask64 _mm512_mask_test_epi8_mask(__mmask64 __U, __m512i __A, __m512i __B)

VPTESTMB k, zmm, zmm EVEX.512 -mavx512bw

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
AVX512BW_128

AVX10.1
CPUID.(EAX=07H,ECX=1):EDX[19] AVX10
CPUID.(EAX=24H,ECX=0):EBX[7:0] ≥ 1 AVX10 version

or

AVX512BW + AVX512VL
CPUID.(EAX=07H,ECX=0):EBX[30] AVX512BW
CPUID.(EAX=07H,ECX=0):EBX[31] AVX512VL

Cannon Lake, Ice Lake (client), Tiger Lake, Nova Lake, Skylake-SP, Cascade Lake, Cooper Lake, Ice Lake (server), Sapphire Rapids, Emerald Rapids, Granite Rapids, Diamond Rapids
AVX512BW_256

AVX10.1
CPUID.(EAX=07H,ECX=1):EDX[19] AVX10
CPUID.(EAX=24H,ECX=0):EBX[7:0] ≥ 1 AVX10 version

or

AVX512BW + AVX512VL
CPUID.(EAX=07H,ECX=0):EBX[30] AVX512BW
CPUID.(EAX=07H,ECX=0):EBX[31] AVX512VL

Cannon Lake, Ice Lake (client), Tiger Lake, Nova Lake, Skylake-SP, Cascade Lake, Cooper Lake, Ice Lake (server), Sapphire Rapids, Emerald Rapids, Granite Rapids, Diamond Rapids
AVX512BW_512

AVX10.1
CPUID.(EAX=07H,ECX=1):EDX[19] AVX10
CPUID.(EAX=24H,ECX=0):EBX[7:0] ≥ 1 AVX10 version

or

AVX512BW
CPUID.(EAX=07H,ECX=0):EBX[30] AVX512BW

Cannon Lake, Ice Lake (client), Tiger Lake, Nova Lake, Skylake-SP, Cascade Lake, Cooper Lake, Ice Lake (server), Sapphire Rapids, Emerald Rapids, Granite Rapids, Diamond Rapids

More AVX10.1 instructions

All 686 AVX10.1 instructions

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 Advanced Vector Extensions 10.2 Architecture Specification, revision 6.0 (361050-006, January 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.