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# atanl.m4 serial 9
dnl Copyright (C) 2010-2023 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_ATANL],
[
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
dnl Persuade glibc <math.h> to declare atanl().
AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
ATANL_LIBM=
AC_CACHE_CHECK([whether atanl() can be used without linking with libm],
[gl_cv_func_atanl_no_libm],
[
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
long double (* volatile funcptr) (long double) = atanl;
long double x;]],
[[return funcptr (x) > 1
|| atanl (x) > 1;]])],
[gl_cv_func_atanl_no_libm=yes],
[gl_cv_func_atanl_no_libm=no])
])
if test $gl_cv_func_atanl_no_libm = no; then
AC_CACHE_CHECK([whether atanl() can be used with libm],
[gl_cv_func_atanl_in_libm],
[
save_LIBS="$LIBS"
LIBS="$LIBS -lm"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#ifndef __NO_MATH_INLINES
# define __NO_MATH_INLINES 1 /* for glibc */
#endif
#include <math.h>
long double (* volatile funcptr) (long double) = atanl;
long double x;]],
[[return funcptr (x) > 1
|| atanl (x) > 1;]])],
[gl_cv_func_atanl_in_libm=yes],
[gl_cv_func_atanl_in_libm=no])
LIBS="$save_LIBS"
])
if test $gl_cv_func_atanl_in_libm = yes; then
ATANL_LIBM=-lm
fi
fi
if test $gl_cv_func_atanl_no_libm = yes \
|| test $gl_cv_func_atanl_in_libm = yes; then
dnl Also check whether it's declared.
dnl Mac OS X 10.3 has atanl() in libc but doesn't declare it in <math.h>.
AC_CHECK_DECL([atanl], , [HAVE_DECL_ATANL=0], [[#include <math.h>]])
else
HAVE_DECL_ATANL=0
HAVE_ATANL=0
dnl Find libraries needed to link lib/atanl.c.
if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
AC_REQUIRE([gl_FUNC_ATAN])
ATANL_LIBM="$ATAN_LIBM"
else
AC_REQUIRE([gl_FUNC_ISNANL])
dnl Append $ISNANL_LIBM to ATANL_LIBM, avoiding gratuitous duplicates.
case " $ATANL_LIBM " in
*" $ISNANL_LIBM "*) ;;
*) ATANL_LIBM="$ATANL_LIBM $ISNANL_LIBM" ;;
esac
fi
fi
AC_SUBST([ATANL_LIBM])
])
|
