Function getHalf01

src/backend/oneapi/kernel/random_engine_write.hpp:76–83

Generates rationals in (0, 1]

// Generates rationals in (0, 1]
sycl::half getHalf01(uint num, uint index) {
    sycl::half v = static_cast<sycl::half>(min(MAX_INT_BEFORE_INFINITY,
                       static_cast<ushort>(num >> (16U * (index & 1U)) & 0x0000ffff)));

    const sycl::half half_factor{1.526e-5}; // (1 / (USHRT_MAX + 1))
    const sycl::half half_half_factor{7.6e-6}; // (0.5 * half_factor)
    return sycl::fma(v, half_factor, half_half_factor);
}

sycl::half oneMinusGetHalf01(uint num, uint index) {
    return static_cast<sycl::half>(1.) - getHalf01(num, index);