tests/test-snan-1.c

   1 /* Tests of signalling not-a-number.
   2    Copyright (C) 2023-2025 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program 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
  15    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Bruno Haible <bruno@clisp.org>, 2023.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include "snan.h"
  23
  24 #if defined __GLIBC__ && defined __arm__ && defined __SOFTFP__
  25
  26 # include <stdio.h>
  27
  28 /* The arm software floating-point emulation (used e.g. on armv5) does not set
  29    the floating-point exception bits.  */
  30
  31 int
  32 main ()
  33 {
  34   fputs ("Skipping test: software floating-point emulation\n", stderr);
  35   return 77;
  36 }
  37
  38 #else
  39
  40 # include <fenv.h>
  41
  42 # include "macros.h"
  43
  44 float volatile resultf;
  45 double volatile resultd;
  46 long double volatile resultl;
  47
  48 int
  49 main ()
  50 {
  51   /* Fetch the NaN values before we start watching out for FE_INVALID
  52      exceptions, because the division 0.0 / 0.0 itself also raises an
  53      FE_INVALID exception.
  54      The use of 'volatile' prevents the compiler from doing constant-folding
  55      optimizations on these values.  An alternative, for GCC only, would be
  56      the command-line option '-fsignaling-nans'.  */
  57   _GL_UNUSED float volatile nanf = SNaNf ();
  58   _GL_UNUSED double volatile nand = SNaNd ();
  59   _GL_UNUSED long double volatile nanl = SNaNl ();
  60
  61   /* Check that the values are really signalling.  */
  62   /* These tests do not work on 32-bit x86 processors, as well as
  63      on x86_64 processors with CC="gcc -mfpmath=387", because loading SNaNf()
  64      or SNaNd() into a 387 FPU register already converted it to a quiet NaN.
  65      See <https://lists.gnu.org/archive/html/bug-gnulib/2023-10/msg00060.html>
  66      for details.  */
  67   #if !((defined __i386 || defined _M_IX86) \
  68         || ((defined __x86_64__ || defined _M_X64) && __FLT_EVAL_METHOD__ == 2))
  69   /* This test does not work on AIX 7.1 with the xlc compiler, even with
  70      the compiler options -qfloat=fenv -qfloat=nans -qfloat=spnans.  */
  71   #if !(defined _AIX && defined __xlC__)
  72   {
  73     feclearexcept (FE_INVALID);
  74     resultf = nanf + 42.0f;
  75     ASSERT (fetestexcept (FE_INVALID));
  76   }
  77   #endif
  78   {
  79     feclearexcept (FE_INVALID);
  80     resultd = nand + 42.0;
  81     ASSERT (fetestexcept (FE_INVALID));
  82   }
  83   #endif
  84   /* This test does not work on eglibc 2.13/mips64
  85      (bug in libc function __addtf3).
  86      This test does not work on FreeBSD/arm64 and OpenBSD/mips64
  87      (bug in libc function __addtf3).
  88      This test does not work on FreeBSD/sparc64 and NetBSD/sparc64
  89      (bug in libc function _Qp_add).
  90      This test does not work on MSVC/i386, because of the general IA-32
  91      problem (see above) and 'long double' == 'double'.  */
  92   #if !((((__GLIBC__ == 2 && __GLIBC_MINOR__ < 19 && defined __mips64) \
  93           || ((defined __FreeBSD__ || defined __NetBSD__ || defined __OpenBSD__) && (defined __aarch64__ || defined __mips64__ || defined __sparc__))) \
  94          && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE) \
  95         || ((defined __i386 || defined _M_IX86) && HAVE_SAME_LONG_DOUBLE_AS_DOUBLE))
  96   {
  97     feclearexcept (FE_INVALID);
  98     resultl = nanl + 42.0L;
  99     ASSERT (fetestexcept (FE_INVALID));
 100   }
 101   #endif
 102
 103   return test_exit_status;
 104 }
 105
 106 #endif