Function activate_float

tests/validation/reference/ActivationLayer.h:39–100

{
template <typename T>
inline T activate_float(T x, T a, T b, ActivationLayerInfo::ActivationFunction activation)
{
    T ret;

    switch (activation)
    {
        case ActivationLayerInfo::ActivationFunction::ABS:
            ret = std::abs(x);
            break;
        case ActivationLayerInfo::ActivationFunction::LINEAR:
            ret = a * x + b;
            break;
        case ActivationLayerInfo::ActivationFunction::LOGISTIC:
            ret = static_cast<T>(1) / (static_cast<T>(1) + std::exp(-x));
            break;
        case ActivationLayerInfo::ActivationFunction::RELU:
            ret = std::max<T>(static_cast<T>(0), x);
            break;
        case ActivationLayerInfo::ActivationFunction::BOUNDED_RELU:
            ret = std::min<T>(a, std::max(static_cast<T>(0), x));
            break;
        case ActivationLayerInfo::ActivationFunction::LU_BOUNDED_RELU:
            ret = std::min<T>(a, std::max<T>(b, x));
            break;
        case ActivationLayerInfo::ActivationFunction::LEAKY_RELU:
            ret = x > static_cast<T>(0) ? x : static_cast<T>(a * x);
            break;
        case ActivationLayerInfo::ActivationFunction::SOFT_RELU:
            ret = std::log(static_cast<T>(1) + std::exp(static_cast<double>(x)));
            break;
        case ActivationLayerInfo::ActivationFunction::ELU:
            ret = x > static_cast<T>(0) ? x : static_cast<T>(a * (std::exp(x) - static_cast<T>(1)));
            break;
        case ActivationLayerInfo::ActivationFunction::SQRT:
            ret = std::sqrt(x);
            break;
        case ActivationLayerInfo::ActivationFunction::SQUARE:
            ret = x * x;
            break;
        case ActivationLayerInfo::ActivationFunction::TANH:
            ret = a * std::tanh(b * x);
            break;
        case ActivationLayerInfo::ActivationFunction::IDENTITY:
            ret = x;
            break;
        case ActivationLayerInfo::ActivationFunction::HARD_SWISH:
            ret = x * ((std::min(std::max(static_cast<T>(x + 3), static_cast<T>(0.0f)), static_cast<T>(6.0f))) *
                       0.166666667f);
            break;
        case ActivationLayerInfo::ActivationFunction::SWISH:
            ret = static_cast<T>(x) / (static_cast<T>(1) + std::exp(-a * x));
            break;
        case ActivationLayerInfo::ActivationFunction::GELU:
            ret = x * 0.5f * (1 + erf(x / std::sqrt(2.0f)));
            break;
        default:
            ARM_COMPUTE_ERROR("Unsupported activation function");
            break;