2 dnl Copyright (C) 2007 Free Software Foundation, Inc.
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.
7 AC_DEFUN([gl_FUNC_ROUNDL],
9 AC_REQUIRE([gl_MATH_H_DEFAULTS])
10 dnl Persuade glibc <math.h> to declare roundl().
11 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
12 dnl Test whether roundl() is declared.
13 gl_CHECK_LIBM_FUNC([roundl], [x = roundl(x);], [], [
14 dnl No. Are both floorl() and ceill() available? If so then we can use
15 dnl them to implement roundl(), on the assumption that they're fast.
16 gl_CHECK_LIBM_FUNC([floorl], [x = floorl(x);], [
17 AC_CHECK_DECL([ceill],
18 [dnl Yes. Both are declared. Link against the necessary library.
19 ROUNDL_LIBM="$FLOORL_LIBM"],
20 [: dnl No. We will use an implementation that doesn't need them.