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naming fix

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This commit is contained in:
myrrc 2020-11-12 15:17:34 +03:00
parent 37c70f4f6a
commit 8c4bb8cd02
1 changed files with 14 additions and 3 deletions
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17
base/common/wide_integer_impl.h
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@ -233,7 +233,7 @@ struct integer<Bits, Signed>::_impl
* the recursive call happens when t / 2^64 > 2^64, so there won't be more than 5 of them.
*/
template <class T>
constexpr static void set_multiplier(wide_integer<Bits, Signed> & self, T t) noexcept {
constexpr static void set_multiplier(integer<Bits, Signed> & self, T t) noexcept {
constexpr uint64_t max_int = std::numeric_limits<uint64_t>::max();
const T alpha = t / max_int;
@ -241,15 +241,26 @@ struct integer<Bits, Signed>::_impl
for (uint64_t i = 0; i < static_cast<uint64_t>(alpha); ++i)
self *= max_int;
else // max(double) / 2^64 will surely contain less than 52 precision bits, so speed up computations.
set_multiplier(self, static_cast<double>(alpha));
set_multiplier<double>(self, alpha);
self += static_cast<uint64_t>(t - alpha * max_int);
}
constexpr static void wide_integer_from_bultin(wide_integer<Bits, Signed>& self, double rhs) noexcept {
constexpr static void wide_integer_from_bultin(integer<Bits, Signed>& self, double rhs) noexcept {
constexpr int64_t max_int = std::numeric_limits<int64_t>::max();
constexpr int64_t min_int = std::numeric_limits<int64_t>::min();
/// There are values in int64 that have more than 53 significant bits (in terms of double
/// representation). Such values, being promoted to double, are rounded up or down. If they are rounded up,
/// the result may not fit in 64 bits.
/// The example of such a number is 9.22337e+18.
/// As to_Integral does a static_cast to int64_t, it may result in UB.
/// The necessary check here is that long double has enough significant (mantissa) bits to store the
/// int64_t max value precisely.
static_assert(LDBL_MANT_DIG >= 64,
"On your system long double has less than 64 precision bits,"
"which may result in UB when initializing double from int64_t");
if ((rhs > 0 && rhs < max_int) || (rhs < 0 && rhs > min_int)) {
self = static_cast<int64_t>(rhs);
return;