math/test-math-iszero.cc

   1 /* Test for the C++ implementation of iszero.
   2    Copyright (C) 2016-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define _GNU_SOURCE 1
  20 #include <math.h>
  21 #include <stdio.h>
  22
  23 #include <limits>
  24
  25 /* Support for _Float128 in std::numeric_limits is limited.
  26    Include ieee754_float128.h and use the bitfields in the union
  27    ieee854_float128.ieee_nan to build corner-case inputs.  */
  28 #if __HAVE_DISTINCT_FLOAT128
  29 # include <ieee754_float128.h>
  30 #endif
  31
  32 static bool errors;
  33
  34 static void
  35 check (int actual, int expected, const char *actual_expr, int line)
  36 {
  37   if (actual != expected)
  38     {
  39       errors = true;
  40       printf ("%s:%d: error: %s\n", __FILE__, line, actual_expr);
  41       printf ("%s:%d:   expected: %d\n", __FILE__, line, expected);
  42       printf ("%s:%d:   actual: %d\n", __FILE__, line, actual);
  43     }
  44 }
  45
  46 #define CHECK(actual, expected) \
  47   check ((actual), (expected), #actual, __LINE__)
  48
  49 template <class T>
  50 static void
  51 check_type ()
  52 {
  53   typedef std::numeric_limits<T> limits;
  54   CHECK (iszero (T{}), 1);
  55   CHECK (iszero (T{0}), 1);
  56   CHECK (iszero (T{-0.0}), 1);
  57   CHECK (iszero (T{1}), 0);
  58   CHECK (iszero (T{-1}), 0);
  59   CHECK (iszero (limits::min ()), 0);
  60   CHECK (iszero (-limits::min ()), 0);
  61   CHECK (iszero (limits::max ()), 0);
  62   CHECK (iszero (-limits::max ()), 0);
  63   if (limits::has_infinity)
  64     {
  65       CHECK (iszero (limits::infinity ()), 0);
  66       CHECK (iszero (-limits::infinity ()), 0);
  67     }
  68   CHECK (iszero (limits::epsilon ()), 0);
  69   CHECK (iszero (-limits::epsilon ()), 0);
  70   if (limits::has_quiet_NaN)
  71     CHECK (iszero (limits::quiet_NaN ()), 0);
  72   if (limits::has_signaling_NaN)
  73     CHECK (iszero (limits::signaling_NaN ()), 0);
  74   if (limits::has_signaling_NaN)
  75     CHECK (iszero (limits::signaling_NaN ()), 0);
  76   CHECK (iszero (limits::denorm_min ()),
  77          std::numeric_limits<T>::has_denorm == std::denorm_absent);
  78   CHECK (iszero (-limits::denorm_min ()),
  79          std::numeric_limits<T>::has_denorm == std::denorm_absent);
  80 }
  81
  82 #if __HAVE_DISTINCT_FLOAT128
  83 static void
  84 check_float128 ()
  85 {
  86   ieee854_float128 q;
  87
  88   q.d = 0.0Q;
  89   CHECK (iszero (q.d), 1);
  90   q.d = -0.0Q;
  91   CHECK (iszero (q.d), 1);
  92   q.d = 1.0Q;
  93   CHECK (iszero (q.d), 0);
  94   q.d = -1.0Q;
  95   CHECK (iszero (q.d), 0);
  96
  97   /* Normal min.  */
  98   q.ieee.negative = 0;
  99   q.ieee.exponent = 0x0001;
 100   q.ieee.mantissa0 = 0x0000;
 101   q.ieee.mantissa1 = 0x00000000;
 102   q.ieee.mantissa2 = 0x00000000;
 103   q.ieee.mantissa3 = 0x00000000;
 104   CHECK (iszero (q.d), 0);
 105   q.ieee.negative = 1;
 106   CHECK (iszero (q.d), 0);
 107
 108   /* Normal max.  */
 109   q.ieee.negative = 0;
 110   q.ieee.exponent = 0x7FFE;
 111   q.ieee.mantissa0 = 0xFFFF;
 112   q.ieee.mantissa1 = 0xFFFFFFFF;
 113   q.ieee.mantissa2 = 0xFFFFFFFF;
 114   q.ieee.mantissa3 = 0xFFFFFFFF;
 115   CHECK (iszero (q.d), 0);
 116   q.ieee.negative = 1;
 117   CHECK (iszero (q.d), 0);
 118
 119   /* Infinity.  */
 120   q.ieee.negative = 0;
 121   q.ieee.exponent = 0x7FFF;
 122   q.ieee.mantissa0 = 0x0000;
 123   q.ieee.mantissa1 = 0x00000000;
 124   q.ieee.mantissa2 = 0x00000000;
 125   q.ieee.mantissa3 = 0x00000000;
 126   CHECK (iszero (q.d), 0);
 127
 128   /* Quiet NaN.  */
 129   q.ieee_nan.quiet_nan = 1;
 130   q.ieee_nan.mantissa0 = 0x0000;
 131   CHECK (iszero (q.d), 0);
 132
 133   /* Signaling NaN.  */
 134   q.ieee_nan.quiet_nan = 0;
 135   q.ieee_nan.mantissa0 = 0x4000;
 136   CHECK (iszero (q.d), 0);
 137
 138   /* Denormal min.  */
 139   q.ieee.negative = 0;
 140   q.ieee.exponent = 0x0000;
 141   q.ieee.mantissa0 = 0x0000;
 142   q.ieee.mantissa1 = 0x00000000;
 143   q.ieee.mantissa2 = 0x00000000;
 144   q.ieee.mantissa3 = 0x00000001;
 145   CHECK (iszero (q.d), 0);
 146   q.ieee.negative = 1;
 147   CHECK (iszero (q.d), 0);
 148 }
 149 #endif
 150
 151 static int
 152 do_test (void)
 153 {
 154   check_type<float> ();
 155   check_type<double> ();
 156   check_type<long double> ();
 157 #if __HAVE_DISTINCT_FLOAT128
 158   check_float128 ();
 159 #endif
 160   return errors;
 161 }
 162
 163 #define TEST_FUNCTION do_test ()
 164 #include "../test-skeleton.c"