libstdc++-v3/testsuite/20_util/to_chars/float16_c++23.cc

   1 // Copyright (C) 2022-2023 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2b" }
  19 // { dg-do run { target c++23 } }
  20 // { dg-require-effective-target ieee_floats }
  21 // { dg-require-effective-target size32plus }
  22 // { dg-add-options ieee }
  23
  24 #include <charconv>
  25 #include <stdfloat>
  26 #include <iostream>
  27 #include <cmath>
  28 #include <testsuite_hooks.h>
  29
  30 template<typename T>
  31 void
  32 test(std::chars_format fmt = std::chars_format{})
  33 {
  34   char str1[128], str2[128], str3[128];
  35   union U { unsigned short s; T f; } u, v;
  36   for (int i = 0; i <= (unsigned short) ~0; ++i)
  37     {
  38       u.s = i;
  39       auto [ptr1, ec1] = (fmt == std::chars_format{}
  40                           ? std::to_chars(str1, str1 + sizeof(str1), u.f)
  41                           : std::to_chars(str1, str1 + sizeof(str1), u.f,
  42                                           fmt));
  43       auto [ptr2, ec2] = (fmt == std::chars_format{}
  44                           ? std::to_chars(str2, str2 + sizeof(str2),
  45                                           std::float32_t(u.f))
  46                           : std::to_chars(str2, str2 + sizeof(str2),
  47                                           std::float32_t(u.f), fmt));
  48       VERIFY( ec1 == std::errc() && ec2 == std::errc() );
  49 //    std::cout << i << ' ' << std::string_view (str1, ptr1)
  50 //      << '\t' << std::string_view (str2, ptr2) << '\n';
  51       if (fmt == std::chars_format::fixed)
  52         {
  53           auto [ptr3, ec3] = std::to_chars(str3, str3 + (ptr1 - str1), u.f, fmt);
  54           VERIFY( ec3 == std::errc() && ptr3 - str3 == ptr1 - str1 );
  55           auto [ptr4, ec4] = std::to_chars(str3, str3 + (ptr1 - str1 - 1), u.f, fmt);
  56           VERIFY( ec4 != std::errc() );
  57         }
  58       auto [ptr5, ec5] = std::from_chars(str1, ptr1, v.f,
  59                                          fmt == std::chars_format{}
  60                                          ? std::chars_format::general : fmt);
  61       VERIFY( ec5 == std::errc() && ptr5 == ptr1 );
  62       VERIFY( u.s == v.s || (std::isnan(u.f) && std::isnan(v.f)) );
  63     }
  64 }
  65
  66 int
  67 main()
  68 {
  69 #ifdef __STDCPP_FLOAT16_T__
  70   test<std::float16_t>();
  71   test<std::float16_t>(std::chars_format::fixed);
  72   test<std::float16_t>(std::chars_format::scientific);
  73   test<std::float16_t>(std::chars_format::general);
  74   test<std::float16_t>(std::chars_format::hex);
  75 #endif
  76 #ifdef __STDCPP_BFLOAT16_T__
  77   test<std::bfloat16_t>();
  78   test<std::bfloat16_t>(std::chars_format::fixed);
  79   test<std::bfloat16_t>(std::chars_format::scientific);
  80   test<std::bfloat16_t>(std::chars_format::general);
  81   test<std::bfloat16_t>(std::chars_format::hex);
  82 #endif
  83 }