diff options
Diffstat (limited to 'libstdc++-v3/src/c++17/floating_to_chars.cc')
| -rw-r--r-- | libstdc++-v3/src/c++17/floating_to_chars.cc | 73 |
1 files changed, 64 insertions, 9 deletions
diff --git a/libstdc++-v3/src/c++17/floating_to_chars.cc b/libstdc++-v3/src/c++17/floating_to_chars.cc index a253ee42416..afce8d74c12 100644 --- a/libstdc++-v3/src/c++17/floating_to_chars.cc +++ b/libstdc++-v3/src/c++17/floating_to_chars.cc @@ -43,6 +43,14 @@ #endif // sprintf for __ieee128 extern "C" int __sprintfieee128(char*, const char*, ...); +#elif __FLT128_MANT_DIG__ == 113 && __LDBL_MANT_DIG__ != 113 \ + && defined(__GLIBC_PREREQ) +extern "C" int __strfromf128(char*, size_t, const char*, _Float128) + __asm ("strfromf128") +#ifndef _GLIBCXX_HAVE_FLOAT128_MATH + __attribute__((__weak__)) +#endif + ; #endif // This implementation crucially assumes float/double have the @@ -77,10 +85,11 @@ extern "C" int __sprintfieee128(char*, const char*, ...); #if defined _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT && __FLT128_MANT_DIG__ == 113 // Define overloads of std::to_chars for __float128. # define FLOAT128_TO_CHARS 1 -#endif - -#ifdef FLOAT128_TO_CHARS using F128_type = __float128; +#elif __FLT128_MANT_DIG__ == 113 && __LDBL_MANT_DIG__ != 113 \ + && defined(__GLIBC_PREREQ) +# define FLOAT128_TO_CHARS 1 +using F128_type = _Float128; #else using F128_type = void; #endif @@ -252,7 +261,7 @@ namespace # ifdef FLOAT128_TO_CHARS template<> - struct floating_type_traits<__float128> : floating_type_traits_binary128 + struct floating_type_traits<F128_type> : floating_type_traits_binary128 { }; # endif #endif @@ -1034,7 +1043,8 @@ namespace #pragma GCC diagnostic ignored "-Wabi" template<typename T, typename... Extra> inline int - sprintf_ld(char* buffer, const char* format_string, T value, Extra... args) + sprintf_ld(char* buffer, size_t length __attribute__((unused)), + const char* format_string, T value, Extra... args) { int len; @@ -1044,10 +1054,31 @@ namespace fesetround(FE_TONEAREST); // We want round-to-nearest behavior. #endif +#ifdef FLOAT128_TO_CHARS #ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT if constexpr (is_same_v<T, __ieee128>) len = __sprintfieee128(buffer, format_string, args..., value); else +#else + if constexpr (is_same_v<T, _Float128>) + { +#ifndef _GLIBCXX_HAVE_FLOAT128_MATH + if (&__strfromf128 == nullptr) + len = sprintf(buffer, format_string, args..., (long double)value); + else +#endif + if constexpr (sizeof...(args) == 0) + len = __strfromf128(buffer, length, "%.0f", value); + else + { + // strfromf128 unfortunately doesn't allow .* + char fmt[3 * sizeof(int) + 6]; + sprintf(fmt, "%%.%d%c", args..., int(format_string[4])); + len = __strfromf128(buffer, length, fmt, value); + } + } + else +#endif #endif len = sprintf(buffer, format_string, args..., value); @@ -1205,8 +1236,10 @@ template<typename T> // can avoid this if we use sprintf to write all but the last // digit, and carefully compute and write the last digit // ourselves. - char buffer[expected_output_length+1]; - const int output_length = sprintf_ld(buffer, "%.0Lf", value); + char buffer[expected_output_length + 1]; + const int output_length = sprintf_ld(buffer, + expected_output_length + 1, + "%.0Lf", value); __glibcxx_assert(output_length == expected_output_length); memcpy(first, buffer, output_length); return {first + output_length, errc{}}; @@ -1396,9 +1429,10 @@ template<typename T> __builtin_unreachable(); // Do the sprintf into the local buffer. - char buffer[output_length_upper_bound+1]; + char buffer[output_length_upper_bound + 1]; int output_length - = sprintf_ld(buffer, output_specifier, value, effective_precision); + = sprintf_ld(buffer, output_length_upper_bound + 1, output_specifier, + value, effective_precision); __glibcxx_assert(output_length <= output_length_upper_bound); if (effective_precision > 0) @@ -1798,6 +1832,7 @@ to_chars(char* first, char* last, long double value, chars_format fmt, } #ifdef FLOAT128_TO_CHARS +#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT to_chars_result to_chars(char* first, char* last, __float128 value) noexcept { @@ -1816,6 +1851,26 @@ to_chars(char* first, char* last, __float128 value, chars_format fmt, { return __floating_to_chars_precision(first, last, value, fmt, precision); } +#else +to_chars_result +to_chars(char* first, char* last, _Float128 value) noexcept +{ + return __floating_to_chars_shortest(first, last, value, chars_format{}); +} + +to_chars_result +to_chars(char* first, char* last, _Float128 value, chars_format fmt) noexcept +{ + return __floating_to_chars_shortest(first, last, value, fmt); +} + +to_chars_result +to_chars(char* first, char* last, _Float128 value, chars_format fmt, + int precision) noexcept +{ + return __floating_to_chars_precision(first, last, value, fmt, precision); +} +#endif #endif // Entrypoints for 16-bit floats. |