libstdc++-v3/testsuite/experimental/simd/tests/frexp.cc

   1 // Copyright (C) 2020-2023 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 // only: float|double|ldouble * * *
  19 // expensive: * [1-9] * *
  20 #include "bits/verify.h"
  21 #include "bits/metahelpers.h"
  22 #include "bits/test_values.h"
  23
  24 template <typename V>
  25   void
  26   test()
  27   {
  28     using int_v = std::experimental::fixed_size_simd<int, V::size()>;
  29     using T = typename V::value_type;
  30     constexpr auto denorm_min = std::__denorm_min_v<T>;
  31     constexpr auto norm_min = std::__norm_min_v<T>;
  32     constexpr auto max = std::__finite_max_v<T>;
  33     constexpr auto nan = std::__quiet_NaN_v<T>;
  34     constexpr auto inf = std::__infinity_v<T>;
  35     test_values<V>(
  36       {0, 0.25, 0.5, 1, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
  37        20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 32, 31, -0., -0.25, -0.5, -1,
  38        -3, -4, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15, -16, -17, -18,
  39        -19, -20, -21, -22, -23, -24, -25, -26, -27, -28, -29, -32, -31,
  40 #if __GCC_IEC_559 >= 2
  41        denorm_min, -denorm_min, norm_min / 2, -norm_min / 2,
  42 #endif
  43        max, -max, max * 0.123f, -max * 0.123f},
  44       [](const V input) {
  45         V expectedFraction;
  46         const int_v expectedExponent([&](auto i) {
  47           int exp;
  48           expectedFraction[i] = std::frexp(input[i], &exp);
  49           return exp;
  50         });
  51         int_v exponent = {};
  52         const V fraction = frexp(input, &exponent);
  53         COMPARE(fraction, expectedFraction) << ", input = " << input
  54           << ", delta: " << fraction - expectedFraction;
  55         COMPARE(exponent, expectedExponent)
  56           << "\ninput: " << input << ", fraction: " << fraction;
  57       });
  58 #ifdef __STDC_IEC_559__
  59     test_values<V>(
  60       // If x is a NaN, a NaN is returned, and the value of *exp is unspecified.
  61       //
  62       // If x is positive  infinity  (negative  infinity),  positive  infinity
  63       // (negative infinity) is returned, and the value of *exp is unspecified.
  64       // This behavior is only guaranteed with C's Annex F when __STDC_IEC_559__
  65       // is defined.
  66       {nan, inf, -inf, denorm_min, denorm_min * 1.72, -denorm_min,
  67        -denorm_min * 1.72, 0., -0., 1, -1},
  68       [](const V input) {
  69         const V expectedFraction([&](auto i) {
  70           int exp;
  71           return std::frexp(input[i], &exp);
  72         });
  73         int_v exponent = {};
  74         const V fraction = frexp(input, &exponent);
  75         COMPARE(isnan(fraction), isnan(expectedFraction))
  76           << fraction << ", input = " << input
  77           << ", delta: " << fraction - expectedFraction;
  78         COMPARE(isinf(fraction), isinf(expectedFraction))
  79           << fraction << ", input = " << input
  80           << ", delta: " << fraction - expectedFraction;
  81         COMPARE(signbit(fraction), signbit(expectedFraction))
  82           << fraction << ", input = " << input
  83           << ", delta: " << fraction - expectedFraction;
  84       });
  85 #endif
  86   }