# isnanl.m4 serial 20

dnl Copyright (C) 2007-2018 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_ISNANL],

[

  AC_REQUIRE([gl_MATH_H_DEFAULTS])

  ISNANL_LIBM=

  gl_HAVE_ISNANL_NO_LIBM

  if test $gl_cv_func_isnanl_no_libm = no; then

    gl_HAVE_ISNANL_IN_LIBM

    if test $gl_cv_func_isnanl_in_libm = yes; then

      ISNANL_LIBM=-lm

    fi

  fi

  dnl The variable gl_func_isnanl set here is used by isnan.m4.

  if test $gl_cv_func_isnanl_no_libm = yes \

     || test $gl_cv_func_isnanl_in_libm = yes; then

    save_LIBS="$LIBS"

    LIBS="$LIBS $ISNANL_LIBM"

    gl_FUNC_ISNANL_WORKS

    LIBS="$save_LIBS"

    case "$gl_cv_func_isnanl_works" in

      *yes) gl_func_isnanl=yes ;;

      *)    gl_func_isnanl=no; ISNANL_LIBM= ;;

    esac

  else

    gl_func_isnanl=no

  fi

  if test $gl_func_isnanl != yes; then

    HAVE_ISNANL=0

  fi

  AC_SUBST([ISNANL_LIBM])

])

AC_DEFUN([gl_FUNC_ISNANL_NO_LIBM],

[

  gl_HAVE_ISNANL_NO_LIBM

  gl_func_isnanl_no_libm=$gl_cv_func_isnanl_no_libm

  if test $gl_func_isnanl_no_libm = yes; then

    gl_FUNC_ISNANL_WORKS

    case "$gl_cv_func_isnanl_works" in

      *yes) ;;

      *)    gl_func_isnanl_no_libm=no ;;

    esac

  fi

  if test $gl_func_isnanl_no_libm = yes; then

    AC_DEFINE([HAVE_ISNANL_IN_LIBC], [1],

      [Define if the isnan(long double) function is available in libc.])

  fi

])

dnl Prerequisites of replacement isnanl definition. It does not need -lm.

AC_DEFUN([gl_PREREQ_ISNANL],

[

  gl_LONG_DOUBLE_EXPONENT_LOCATION

  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])

])

dnl Test whether isnanl() can be used without libm.

AC_DEFUN([gl_HAVE_ISNANL_NO_LIBM],

[

  AC_CACHE_CHECK([whether isnan(long double) can be used without linking with libm],

    [gl_cv_func_isnanl_no_libm],

    [

      AC_LINK_IFELSE(

        [AC_LANG_PROGRAM(

           [[#include <math.h>

             #if __GNUC__ >= 4

             # undef isnanl

             # define isnanl(x) __builtin_isnanl ((long double)(x))

             #elif defined isnan

             # undef isnanl

             # define isnanl(x) isnan ((long double)(x))

             #endif

             long double x;]],

           [[return isnanl (x);]])],

        [gl_cv_func_isnanl_no_libm=yes],

        [gl_cv_func_isnanl_no_libm=no])

    ])

])

dnl Test whether isnanl() can be used with libm.

AC_DEFUN([gl_HAVE_ISNANL_IN_LIBM],

[

  AC_CACHE_CHECK([whether isnan(long double) can be used with libm],

    [gl_cv_func_isnanl_in_libm],

    [

      save_LIBS="$LIBS"

      LIBS="$LIBS -lm"

      AC_LINK_IFELSE(

        [AC_LANG_PROGRAM(

           [[#include <math.h>

             #if __GNUC__ >= 4

             # undef isnanl

             # define isnanl(x) __builtin_isnanl ((long double)(x))

             #elif defined isnan

             # undef isnanl

             # define isnanl(x) isnan ((long double)(x))

             #endif

             long double x;]],

           [[return isnanl (x);]])],

        [gl_cv_func_isnanl_in_libm=yes],

        [gl_cv_func_isnanl_in_libm=no])

      LIBS="$save_LIBS"

    ])

])

dnl Test whether isnanl() recognizes all canonical numbers which are neither

dnl finite nor infinite.

AC_DEFUN([gl_FUNC_ISNANL_WORKS],

[

  AC_REQUIRE([AC_PROG_CC])

  AC_REQUIRE([gl_BIGENDIAN])

  AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])

  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

  AC_CACHE_CHECK([whether isnanl works], [gl_cv_func_isnanl_works],

    [

      AC_RUN_IFELSE(

        [AC_LANG_SOURCE([[

#include <float.h>

#include <limits.h>

#include <math.h>

#if __GNUC__ >= 4

# undef isnanl

# define isnanl(x) __builtin_isnanl ((long double)(x))

#elif defined isnan

# undef isnanl

# define isnanl(x) isnan ((long double)(x))

#endif

#define NWORDS \

  ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))

typedef union { unsigned int word[NWORDS]; long double value; }

        memory_long_double;

/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the

   runtime type conversion.  */

#ifdef __sgi

static long double NaNl ()

{

  double zero = 0.0;

  return zero / zero;

}

#else

# define NaNl() (0.0L / 0.0L)

#endif

int main ()

{

  int result = 0;

  if (!isnanl (NaNl ()))

    result |= 1;

  {

    memory_long_double m;

    unsigned int i;

    /* The isnanl function should be immune against changes in the sign bit and

       in the mantissa bits.  The xor operation twiddles a bit that can only be

       a sign bit or a mantissa bit (since the exponent never extends to

       bit 31).  */

    m.value = NaNl ();

    m.word[NWORDS / 2] ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);

    for (i = 0; i < NWORDS; i++)

      m.word[i] |= 1;

    if (!isnanl (m.value))

      result |= 1;

  }

#if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE

/* Representation of an 80-bit 'long double' as an initializer for a sequence

   of 'unsigned int' words.  */

# ifdef WORDS_BIGENDIAN

#  define LDBL80_WORDS(exponent,manthi,mantlo) \

     { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \

       ((unsigned int) (manthi) << 16) | ((unsigned int) (mantlo) >> 16),   \

       (unsigned int) (mantlo) << 16                                        \

     }

# else

#  define LDBL80_WORDS(exponent,manthi,mantlo) \

     { mantlo, manthi, exponent }

# endif

  { /* Quiet NaN.  */

    static memory_long_double x =

      { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) };

    if (!isnanl (x.value))

      result |= 2;

  }

  {

    /* Signalling NaN.  */

    static memory_long_double x =

      { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) };

    if (!isnanl (x.value))

      result |= 2;

  }

  /* isnanl should return something even for noncanonical values.  */

  { /* Pseudo-NaN.  */

    static memory_long_double x =

      { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) };

    if (isnanl (x.value) && !isnanl (x.value))

      result |= 4;

  }

  { /* Pseudo-Infinity.  */

    static memory_long_double x =

      { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) };

    if (isnanl (x.value) && !isnanl (x.value))

      result |= 8;

  }

  { /* Pseudo-Zero.  */

    static memory_long_double x =

      { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) };

    if (isnanl (x.value) && !isnanl (x.value))

      result |= 16;

  }

  { /* Unnormalized number.  */

    static memory_long_double x =

      { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) };

    if (isnanl (x.value) && !isnanl (x.value))

      result |= 32;

  }

  { /* Pseudo-Denormal.  */

    static memory_long_double x =

      { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) };

    if (isnanl (x.value) && !isnanl (x.value))

      result |= 64;

  }

#endif

  return result;

}]])],

        [gl_cv_func_isnanl_works=yes],

        [gl_cv_func_isnanl_works=no],

        [case "$host_os" in

           mingw*) # Guess yes on mingw, no on MSVC.

             AC_EGREP_CPP([Known], [

#ifdef __MINGW32__

 Known

#endif

               ],

               [gl_cv_func_isnanl_works="guessing yes"],

               [gl_cv_func_isnanl_works="guessing no"])

             ;;

           *) gl_cv_func_isnanl_works="guessing yes" ;;

         esac

        ])

    ])

])