# Extra Clang Tools 18.1.8 documentation

## clang-tidy - portability-simd-intrinsics

# portability-simd-intrinsics

Finds SIMD intrinsics calls and suggests `std::experimental::simd` (P0214) alternatives.

If the option `Suggest` is set to true, for

    _mm_add_epi32(a, b); // x86
    vec_add(a, b);       // Power

the check suggests an alternative: `operator+` on `std::experimental::simd` objects.

Otherwise, it just complains the intrinsics are non-portable (and there are P0214 alternatives).

Many architectures provide SIMD operations (e.g. x86 SSE/AVX, Power AltiVec/VSX, ARM NEON). It is common that SIMD code implementing the same algorithm, is written in multiple target-dispatching pieces to optimize for different architectures or micro-architectures.

The C++ standard proposal P0214 and its extensions cover many common SIMD operations. By migrating from target-dependent intrinsics to P0214 operations, the SIMD code can be simplified and pieces for different targets can be unified.

Refer to P0214 for introduction and motivation for the data-parallel standard library.

## Options

Suggest

  If this option is set to true (default is false), the check will suggest P0214 alternatives, otherwise it only points out the intrinsic function is non-portable.

Std

  The namespace used to suggest P0214 alternatives. If not specified, std:: for -std=c++20 and std::experimental:: for -std=c++11.