| # atanl.m4 serial 9 |
| dnl Copyright (C) 2010-2020 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]) |
| ]) |