BoostSIMD

BoostSIMD is a C++ library in the Boost ecosystem that provides portable SIMD programming abstractions. It enables developers to write vectorized code that can map to the hardware instructions of the host processor, offering a single, uniform API across x86, ARM, and other architectures.

At its core is a template vector type, such as pack<T, N>, representing N elements of type T. Operations on packs mimic standard arithmetic, logical, and bitwise operators, and include reductions, transpositions, and element-wise functions. The library also offers mask types for conditional operations, as well as load and store utilities for aligned and unaligned memory access and gather/scatter for non-contiguous data.

BoostSIMD uses a backend dispatch mechanism to select architecture-specific implementations at compile time. The high-level operations are translated into the appropriate intrinsics for the target platform, with the aim of producing efficient vector code while preserving a high-level, portable interface. The design emphasizes zero-overhead abstractions so scalar code remains valid on non-SIMD platforms.

Interoperability with Boost and generic programming facilities is a key goal. BoostSIMD integrates with Boost.Dispatch to enable overloading and selection based on type and context, and it is intended to work in conjunction with Boost.Numeric, algorithms, and other components to support portable performance-oriented code.

Typical use cases include numerical simulation, signal processing, and multimedia applications where performance portable code is desirable. Documentation and development focus on portability, clarity of API, and extensibility to new backends as hardware evolves.