Merge pull request #756 from cppalliance/ldbl_conv

Enable 80 and 128 bit long double conversions
cppalliance · Oct 7, 2024 · 1b5d18a · 1b5d18a
2 parents f6675a9 + 833b6e3
commit 1b5d18a
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Showing 4 changed files with 5 additions and 8 deletions.
diff --git a/include/boost/decimal/decimal64.hpp b/include/boost/decimal/decimal64.hpp
@@ -970,8 +970,7 @@ BOOST_DECIMAL_CXX20_CONSTEXPR decimal64::operator double() const noexcept
 
 BOOST_DECIMAL_CXX20_CONSTEXPR decimal64::operator long double() const noexcept
 {
- // TODO(mborland): Don't have an exact way of converting to various long doubles
- return static_cast<long double>(to_float<decimal64, double>(*this));
+ return to_float<decimal64, long double>(*this);
 }
 
 #ifdef BOOST_DECIMAL_HAS_FLOAT16

diff --git a/include/boost/decimal/decimal64_fast.hpp b/include/boost/decimal/decimal64_fast.hpp
@@ -890,8 +890,7 @@ BOOST_DECIMAL_CXX20_CONSTEXPR decimal64_fast::operator double() const noexcept
 
 BOOST_DECIMAL_CXX20_CONSTEXPR decimal64_fast::operator long double() const noexcept
 {
- // TODO(mborland): Don't have an exact way of converting to various long doubles
- return static_cast<long double>(to_float<decimal64_fast, double>(*this));
+ return to_float<decimal64_fast, long double>(*this);
 }
 
 #ifdef BOOST_DECIMAL_HAS_FLOAT16

diff --git a/include/boost/decimal/detail/fast_float/compute_float80_128.hpp b/include/boost/decimal/detail/fast_float/compute_float80_128.hpp
@@ -69,8 +69,8 @@ constexpr auto fast_path(const std::int64_t q, const Unsigned_Integer &w, bool n
 #endif
 
 template <typename Unsigned_Integer>
-constexpr auto compute_float80(std::int64_t q, const Unsigned_Integer &w,
- const bool negative, bool &success) noexcept -> long double
+constexpr auto compute_float80_128(std::int64_t q, const Unsigned_Integer &w,
+  const bool negative, bool &success) noexcept -> long double
 {
  // GLIBC uses 2^-16444 but MPFR uses 2^-16445 as the smallest subnormal value for 80 bit
  // 39 is the max number of digits in an uint128_t

diff --git a/include/boost/decimal/detail/to_float.hpp b/include/boost/decimal/detail/to_float.hpp
@@ -72,10 +72,9 @@ BOOST_DECIMAL_CXX20_CONSTEXPR auto to_float(Decimal val) noexcept
  #if BOOST_DECIMAL_LDBL_BITS == 64
  result = static_cast<TargetType>(detail::fast_float::compute_float64(exp, new_sig, val.isneg(), success));
  #else
- result = static_cast<TargetType>(detail::fast_float::compute_float80(exp, new_sig, val.isneg(), success));
+ result = static_cast<TargetType>(detail::fast_float::compute_float80_128(exp, new_sig, val.isneg(), success));
  #endif
  }
- // TODO(mborland): Add conversion for __float128 and 128 bit long doubles
 
  if (BOOST_DECIMAL_UNLIKELY(!success))
  {