| 1 | // Copyright 2023 Matt Borland |
|---|---|
| 2 | // Distributed under the Boost Software License, Version 1.0. |
| 3 | // https://www.boost.org/LICENSE_1_0.txt |
| 4 | |
| 5 | #ifndef BOOST_CHARCONV_DETAIL_COMPUTE_FLOAT32_HPP |
| 6 | #define BOOST_CHARCONV_DETAIL_COMPUTE_FLOAT32_HPP |
| 7 | |
| 8 | #include <boost/charconv/detail/compute_float64.hpp> |
| 9 | #include <limits> |
| 10 | #include <cstdint> |
| 11 | #include <cmath> |
| 12 | |
| 13 | namespace boost { namespace charconv { namespace detail { |
| 14 | |
| 15 | inline float compute_float32(std::int64_t power, std::uint64_t i, bool negative, bool& success) noexcept |
| 16 | { |
| 17 | const double d = compute_float64(power, i, negative, success); |
| 18 | float return_val; |
| 19 | |
| 20 | if (success) |
| 21 | { |
| 22 | // Some compilers (e.g. Intel) will optimize std::isinf to always false depending on compiler flags |
| 23 | // |
| 24 | // From Intel(R) oneAPI DPC++/C++ Compiler 2023.0.0 (2023.0.0.20221201) |
| 25 | // warning: comparison with infinity always evaluates to false in fast floating point modes [-Wtautological-constant-compare] |
| 26 | // if (std::isinf(return_val)) |
| 27 | if (d > static_cast<double>((std::numeric_limits<float>::max)()) || |
| 28 | d < static_cast<double>((std::numeric_limits<float>::lowest)())) |
| 29 | { |
| 30 | return_val = negative ? -HUGE_VALF : HUGE_VALF; |
| 31 | success = false; |
| 32 | } |
| 33 | else |
| 34 | { |
| 35 | return_val = static_cast<float>(d); |
| 36 | } |
| 37 | } |
| 38 | else |
| 39 | { |
| 40 | if (power > 38) |
| 41 | { |
| 42 | return_val = negative ? -HUGE_VALF : HUGE_VALF; |
| 43 | } |
| 44 | else |
| 45 | { |
| 46 | return_val = negative ? -0.0F : 0.0F; |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | return return_val; |
| 51 | } |
| 52 | |
| 53 | }}} // Namespaces |
| 54 | |
| 55 | #endif // BOOST_CHARCONV_DETAIL_COMPUTE_FLOAT32_HPP |
| 56 |