Function EncodeDouble

src/util/serfloat.cpp:37–64

}

uint64_t EncodeDouble(double f) noexcept {
    int cls = std::fpclassify(f);
    uint64_t sign = 0;
    if (copysign(1.0, f) == -1.0) {
        f = -f;
        sign = 0x8000000000000000;
    }
    // Zero
    if (cls == FP_ZERO) return sign;
    // Infinity
    if (cls == FP_INFINITE) return sign | 0x7ff0000000000000;
    // NaN
    if (cls == FP_NAN) return 0x7ff8000000000000;
    // Other numbers
    int exp;
    uint64_t man = std::round(std::frexp(f, &exp) * 9007199254740992.0);
    if (exp < -1021) {
        // Too small to represent, encode 0
        if (exp < -1084) return sign;
        // Subnormal numbers
        return sign | (man >> (-1021 - exp));
    } else {
        // Too big to represent, encode infinity
        if (exp > 1024) return sign | 0x7ff0000000000000;
        // Normal numbers
        return sign | (((uint64_t)(1022 + exp)) << 52) | (man & 0xFFFFFFFFFFFFF);
    }
}