CPU Feature Inspector

A collection of small C++17 command-line tools that query x86 processor capabilities directly through the CPUID instruction and demonstrate how a 128-bit integer SIMD register can be interpreted at different element widths.

What it inspects

Executable	Source	Purpose
cpu_identity	cpu_identity.cpp	Reads the processor brand string and CPUID frequency leaf when available.
cpu_topology	cpu_topology.cpp	Uses CPUID leaf 0x0B to report threads per core, logical threads, and derived physical-core count.
cache_hierarchy	cache_hierarchy.cpp	Enumerates deterministic cache parameters from leaf 0x04, including level, type, size, line size, ways, and sets.
simd_features	simd_features.cpp	Detects MMX, SSE generations, AES-NI, AVX, AVX2, and SHA feature bits.
simd_register_view	simd_register_view.cpp	Prints the same __m128i value as signed and unsigned 8-, 16-, 32-, and 64-bit lanes.

Implementation notes

The tools use GCC/Clang's <cpuid.h> helpers. Cache size is derived from CPUID's line-size, partition, associativity, and set fields. Feature detection reports hardware CPUID bits; it does not verify operating-system support for saving extended AVX state.

Build

Requirements:

• an x86 or x86-64 processor;
• GCC or Clang with <cpuid.h> and SIMD intrinsic headers;
• CMake 3.16 or newer.

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Each source is also standalone. For example:

g++ -std=c++17 -O2 src/cpu_identity.cpp -o cpu_identity
g++ -std=c++17 -O2 src/simd_register_view.cpp -o simd_register_view

Run the generated executables individually. Their output depends on the current processor and firmware configuration.

Limitations

• CPUID leaves are not checked uniformly in every small tool; unsupported or differently structured leaves can produce incomplete results.
• Topology leaf 0x0B is Intel-oriented and may not be the preferred topology interface on every x86 processor.
• Frequency leaf 0x16 is optional and does not represent instantaneous clock speed.
• The feature checker reports hardware flags only and should not be used alone to decide whether AVX instructions are safe to execute.
• The original report is not included because its screenshots expose local paths, participant identifiers, and machine-specific details. The source code is self-contained.