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dd36ce77 | 1 | # ldexp.m4 serial 1 |
f0007cad | 2 | dnl Copyright (C) 2010-2012 Free Software Foundation, Inc. |
dd36ce77 MW |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | AC_DEFUN([gl_FUNC_LDEXP], | |
8 | [ | |
9 | AC_REQUIRE([gl_CHECK_LDEXP_NO_LIBM]) | |
10 | LDEXP_LIBM= | |
11 | if test $gl_cv_func_ldexp_no_libm = no; then | |
12 | AC_CACHE_CHECK([whether ldexp() can be used with libm], | |
13 | [gl_cv_func_ldexp_in_libm], | |
14 | [ | |
15 | save_LIBS="$LIBS" | |
16 | LIBS="$LIBS -lm" | |
17 | AC_LINK_IFELSE( | |
18 | [AC_LANG_PROGRAM([[#ifndef __NO_MATH_INLINES | |
19 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
20 | #endif | |
21 | #include <math.h> | |
22 | double (*funcptr) (double, int) = ldexp; | |
23 | double x;]], | |
24 | [[return ldexp (x, -1) > 0;]])], | |
25 | [gl_cv_func_ldexp_in_libm=yes], | |
26 | [gl_cv_func_ldexp_in_libm=no]) | |
27 | LIBS="$save_LIBS" | |
28 | ]) | |
29 | if test $gl_cv_func_ldexp_in_libm = yes; then | |
30 | LDEXP_LIBM=-lm | |
31 | fi | |
32 | fi | |
33 | AC_SUBST([LDEXP_LIBM]) | |
34 | ]) | |
35 | ||
36 | dnl Test whether ldexp() can be used without linking with libm. | |
37 | dnl Set gl_cv_func_ldexp_no_libm to 'yes' or 'no' accordingly. | |
38 | AC_DEFUN([gl_CHECK_LDEXP_NO_LIBM], | |
39 | [ | |
40 | AC_CACHE_CHECK([whether ldexp() can be used without linking with libm], | |
41 | [gl_cv_func_ldexp_no_libm], | |
42 | [ | |
43 | AC_LINK_IFELSE( | |
44 | [AC_LANG_PROGRAM([[#ifndef __NO_MATH_INLINES | |
45 | # define __NO_MATH_INLINES 1 /* for glibc */ | |
46 | #endif | |
47 | #include <math.h> | |
48 | double (*funcptr) (double, int) = ldexp; | |
49 | double x;]], | |
50 | [[return ldexp (x, -1) > 0;]])], | |
51 | [gl_cv_func_ldexp_no_libm=yes], | |
52 | [gl_cv_func_ldexp_no_libm=no]) | |
53 | ]) | |
54 | ]) |