mirror of
https://github.com/fastfloat/fast_float.git
synced 2025-12-06 16:56:57 +08:00
122 lines
4.3 KiB
C++
122 lines
4.3 KiB
C++
#include "fast_float/fast_float.h"
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#include <cassert>
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#include <cmath>
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#if defined(__CYGWIN__) || defined(__MINGW32__) || defined(__MINGW64__)
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// Anything at all that is related to cygwin, msys and so forth will
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// always use this fallback because we cannot rely on it behaving as normal
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// gcc.
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#include <locale>
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#include <sstream>
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// workaround for CYGWIN
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double cygwin_strtod_l(const char* start, char** end) {
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double d;
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std::stringstream ss;
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ss.imbue(std::locale::classic());
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ss << start;
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ss >> d;
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size_t nread = ss.tellg();
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*end = const_cast<char*>(start) + nread;
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return d;
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}
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#endif
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template <typename T> char *to_string(T d, char *buffer) {
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auto written = std::snprintf(buffer, 64, "%.*e",
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std::numeric_limits<T>::max_digits10 - 1, d);
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return buffer + written;
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}
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void strtod_from_string(const char * st, float& d) {
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char *pr = (char *)st;
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#if defined(__CYGWIN__) || defined(__MINGW32__) || defined(__MINGW64__)
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d = cygwin_strtod_l(st, &pr);
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#elif defined(_WIN32)
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static _locale_t c_locale = _create_locale(LC_ALL, "C");
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d = _strtof_l(st, &pr, c_locale);
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#else
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static locale_t c_locale = newlocale(LC_ALL_MASK, "C", NULL);
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d = strtof_l(st, &pr, c_locale);
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#endif
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if (pr == st) {
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throw std::runtime_error("bug in strtod_from_string");
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}
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}
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void allvalues() {
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char buffer[64];
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for (uint64_t w = 0; w <= 0xFFFFFFFF; w++) {
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float v;
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if ((w % 1048576) == 0) {
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std::cout << ".";
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std::cout.flush();
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}
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uint32_t word = w;
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memcpy(&v, &word, sizeof(v));
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if(std::isfinite(v)) {
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float nextf = std::nextafterf(v, INFINITY);
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if(copysign(1,v) != copysign(1,nextf)) { continue; }
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if(!std::isfinite(nextf)) { continue; }
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double v1{v};
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assert(float(v1) == v);
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double v2{nextf};
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assert(float(v2) == nextf);
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double midv{v1 + (v2 - v1) / 2};
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float expected_midv(midv);
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const char *string_end = to_string(midv, buffer);
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float str_answer;
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strtod_from_string(buffer, str_answer);
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float result_value;
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auto result = fast_float::from_chars(buffer, string_end, result_value);
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if (result.ec != std::errc()) {
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std::cerr << "parsing error ? " << buffer << std::endl;
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abort();
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}
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if(copysign(1,result_value) != copysign(1,v)) {
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std::cerr << buffer << std::endl;
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std::cerr << "v " << std::hexfloat << v << std::endl;
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std::cerr << "v2 " << std::hexfloat << v2 << std::endl;
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std::cerr << "midv " << std::hexfloat << midv << std::endl;
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std::cerr << "expected_midv " << std::hexfloat << expected_midv << std::endl;
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std::cerr << "I got " << std::hexfloat << result_value << " but I was expecting " << v
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<< std::endl;
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abort();
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} else if (std::isnan(v)) {
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if (!std::isnan(result_value)) {
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std::cerr << "not nan" << buffer << std::endl;
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std::cerr << "v " << std::hexfloat << v << std::endl;
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std::cerr << "v2 " << std::hexfloat << v2 << std::endl;
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std::cerr << "midv " << std::hexfloat << midv << std::endl;
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std::cerr << "expected_midv " << std::hexfloat << expected_midv << std::endl;
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abort();
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}
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} else if (result_value != str_answer) {
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std::cerr << "no match ? " << buffer << std::endl;
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std::cerr << "v " << std::hexfloat << v << std::endl;
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std::cerr << "v2 " << std::hexfloat << v2 << std::endl;
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std::cerr << "midv " << std::hexfloat << midv << std::endl;
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std::cerr << "expected_midv " << std::hexfloat << expected_midv << std::endl;
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std::cout << "started with " << std::hexfloat << midv << std::endl;
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std::cout << "round down to " << std::hexfloat << str_answer << std::endl;
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std::cout << "got back " << std::hexfloat << result_value << std::endl;
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std::cout << std::dec;
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abort();
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}
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}
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}
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std::cout << std::endl;
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}
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int main() {
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#if defined(__CYGWIN__) || defined(__MINGW32__) || defined(__MINGW64__)
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std::cout << "Warning: msys/cygwin detected. This particular test is likely to generate false failures due to our reliance on the underlying runtime library." << std::endl;
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#endif
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allvalues();
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std::cout << std::endl;
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std::cout << "all ok" << std::endl;
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return EXIT_SUCCESS;
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} |