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Make computing powers BOOST_CXX14_CONSTEXPR

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This commit is contained in:
Matt Borland
2023-03-23 18:47:18 -07:00
parent a9c10ba659
commit 562bd84a7d
1 changed files with 9 additions and 7 deletions
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16
include/boost/charconv/detail/floff.hpp
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@@ -596,7 +596,7 @@ namespace jkj { namespace floff {
////////////////////////////////////////////////////////////////////////////////////////
template <class Int>
constexpr Int compute_power(Int a, unsigned int exp) noexcept {
BOOST_CHARCONV_CXX14_CONSTEXPR Int compute_power(Int a, unsigned int exp) noexcept {
Int res = 1;
while (exp > 0) {
if (exp % 2 != 0) {
@@ -608,6 +608,7 @@ namespace jkj { namespace floff {
return res;
}
/*
template <unsigned int exp>
struct power_of_10_impl {
static_assert(exp <= 19);
@@ -615,6 +616,7 @@ namespace jkj { namespace floff {
static constexpr type value = compute_power(type(10), exp);
};
*/
static constexpr std::uint64_t power_of_10[] = {
UINT64_C(1), UINT64_C(10), UINT64_C(100), UINT64_C(1000), UINT64_C(10000),
@@ -1303,9 +1305,9 @@ namespace jkj { namespace floff {
return false;
}
constexpr std::uint64_t mod_inv =
BOOST_CXX14_CONSTEXPR std::uint64_t mod_inv =
compute_power(0xcccccccccccccccd, (unsigned int)(min_neg_exp_of_5));
constexpr std::uint64_t max_quot =
BOOST_CXX14_CONSTEXPR std::uint64_t max_quot =
0xffffffffffffffff /
compute_power(std::uint64_t(5), (unsigned int)(min_neg_exp_of_5));
@@ -1328,18 +1330,18 @@ namespace jkj { namespace floff {
}
if (k >= k_middle_threshold) {
constexpr std::uint64_t mod_inv =
BOOST_CXX14_CONSTEXPR std::uint64_t mod_inv =
compute_power(0xcccccccccccccccd, (unsigned int)(min_neg_exp_of_5));
constexpr std::uint64_t max_quot =
BOOST_CXX14_CONSTEXPR std::uint64_t max_quot =
0xffffffffffffffff /
compute_power(std::uint64_t(5), (unsigned int)(min_neg_exp_of_5));
return (significand * mod_inv) > max_quot;
}
else {
constexpr std::uint64_t mod_inv = compute_power(
BOOST_CXX14_CONSTEXPR std::uint64_t mod_inv = compute_power(
0xcccccccccccccccd, (unsigned int)(min_neg_exp_of_5 + segment_length));
constexpr std::uint64_t max_quot =
BOOST_CXX14_CONSTEXPR std::uint64_t max_quot =
0xffffffffffffffff /
compute_power(std::uint64_t(5),
(unsigned int)(min_neg_exp_of_5 + segment_length));