| // Copyright 2018 Ulf Adams |
| // |
| // The contents of this file may be used under the terms of the Apache License, |
| // Version 2.0. |
| // |
| // (See accompanying file LICENSE-Apache or copy at |
| // http://www.apache.org/licenses/LICENSE-2.0) |
| // |
| // Alternatively, the contents of this file may be used under the terms of |
| // the Boost Software License, Version 1.0. |
| // (See accompanying file LICENSE-Boost or copy at |
| // https://www.boost.org/LICENSE_1_0.txt) |
| // |
| // Unless required by applicable law or agreed to in writing, this software |
| // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. |
| #ifndef RYU_GENERIC_128_H |
| #define RYU_GENERIC_128_H |
| |
| |
| // NOTE: These symbols are declared extern "C" upstream, but we don't want that |
| // because it'd override the internal linkage of the anonymous namespace into |
| // which this header is included. |
| |
| // This is a generic 128-bit implementation of float to shortest conversion |
| // using the Ryu algorithm. It can handle any IEEE-compatible floating-point |
| // type up to 128 bits. In order to use this correctly, you must use the |
| // appropriate *_to_fd128 function for the underlying type - DO NOT CAST your |
| // input to another floating-point type, doing so will result in incorrect |
| // output! |
| // |
| // For any floating-point type that is not natively defined by the compiler, |
| // you can use generic_binary_to_decimal to work directly on the underlying bit |
| // representation. |
| |
| #define FD128_EXCEPTIONAL_EXPONENT 0x7FFFFFFF |
| |
| // A floating decimal representing (-1)^s * m * 10^e. |
| struct floating_decimal_128 { |
| uint128_t mantissa; |
| int32_t exponent; |
| bool sign; |
| }; |
| |
| // Converts the given decimal floating point number to a string, writing to result, and returning |
| // the number characters written. Does not terminate the buffer with a 0. In the worst case, this |
| // function can write up to 53 characters. |
| // |
| // Maximal char buffer requirement: |
| // sign + mantissa digits + decimal dot + 'E' + exponent sign + exponent digits |
| // = 1 + 39 + 1 + 1 + 1 + 10 = 53 |
| int generic_to_chars(const struct floating_decimal_128 v, char* const result); |
| |
| |
| #endif // RYU_GENERIC_128_H |
