lanes.hpp

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#pragma once

 
#include <cstddef>
#include <type_traits>
 
namespace pulp::simd {
 
#if (defined(__GNUC__) || defined(__clang__)) && !defined(PULP_SIMD_DISABLE_VECTOR_LANES)
#define PULP_SIMD_HAS_VECTOR_LANES 1
inline constexpr bool kHasVectorLanes = true;
 
namespace detail {
template <typename T, std::size_t N> struct vector_lanes {
    static_assert(std::is_arithmetic_v<T> && N > 1 && (N & (N - 1)) == 0,
                  "Lanes needs an arithmetic element type and a power-of-two width above 1");
    typedef T type __attribute__((vector_size(N * sizeof(T))));
};
} // namespace detail

template <typename T, std::size_t N> using Lanes = typename detail::vector_lanes<T, N>::type;
#else
#define PULP_SIMD_HAS_VECTOR_LANES 0
inline constexpr bool kHasVectorLanes = false;
#endif

template <typename V>
inline constexpr std::size_t lane_count = [] {
    if constexpr (std::is_arithmetic_v<V>)
        return std::size_t{1};
    else
        return sizeof(V) / sizeof(V{}[0]);
}();

template <typename V> inline auto get_lane(const V& v, std::size_t i) noexcept {
    if constexpr (std::is_arithmetic_v<V>) {
        (void)i;
        return v;
    } else {
        return v[i];
    }
}

template <typename V, typename T> inline void set_lane(V& v, std::size_t i, T x) noexcept {
    if constexpr (std::is_arithmetic_v<V>) {
        (void)i;
        v = static_cast<V>(x);
    } else {
        v[i] = x;
    }
}
 
} // namespace pulp::simd