2 dnl Copyright (C) 2010-2012 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_EXP2L],
9 m4_divert_text([DEFAULTS], [gl_exp2l_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 AC_REQUIRE([gl_LONG_DOUBLE_VS_DOUBLE])
12 AC_REQUIRE([gl_FUNC_EXP2])
14 dnl Persuade glibc <math.h> to declare exp2l().
15 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
17 dnl Test whether exp2l() exists. Assume that exp2l(), if it exists, is
18 dnl defined in the same library as exp2().
20 LIBS="$LIBS $EXP2_LIBM"
21 AC_CHECK_FUNCS([exp2l])
23 if test $ac_cv_func_exp2l = yes; then
25 EXP2L_LIBM="$EXP2_LIBM"
26 dnl Also check whether it's declared.
27 dnl IRIX 6.5 has exp2l() in libm but doesn't declare it in <math.h>.
28 AC_CHECK_DECL([exp2l], , [HAVE_DECL_EXP2L=0], [[#include <math.h>]])
29 m4_ifdef([gl_FUNC_EXP2L_IEEE], [
30 if test $gl_exp2l_required = ieee && test $REPLACE_EXP2L = 0; then
31 AC_CACHE_CHECK([whether exp2l works according to ISO C 99 with IEC 60559],
32 [gl_cv_func_exp2l_ieee],
35 LIBS="$LIBS $EXP2L_LIBM"
38 #ifndef __NO_MATH_INLINES
39 # define __NO_MATH_INLINES 1 /* for glibc */
47 long double exp2l (long double);
48 static long double dummy (long double x) { return 0; }
49 static long double zero;
50 int main (int argc, char *argv[])
52 long double (*my_exp2l) (long double) = argc ? exp2l : dummy;
54 /* This test fails on OpenBSD 4.9, where exp2l(NaN) = 0.0. */
55 if (exp2l (zero / zero) == 0.0L)
57 /* This test fails on IRIX 6.5, where exp2l(-Inf) = 1.0. */
58 if (!(exp2l (-1.0L / zero) == 0.0L))
63 [gl_cv_func_exp2l_ieee=yes],
64 [gl_cv_func_exp2l_ieee=no],
65 [gl_cv_func_exp2l_ieee="guessing no"])
68 case "$gl_cv_func_exp2l_ieee" in
78 if test $HAVE_EXP2L = 0 || test $REPLACE_EXP2L = 1; then
79 dnl Find libraries needed to link lib/exp2l.c.
80 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
81 EXP2L_LIBM="$EXP2_LIBM"
83 AC_REQUIRE([gl_FUNC_ISNANL])
84 AC_REQUIRE([gl_FUNC_ROUNDL])
85 AC_REQUIRE([gl_FUNC_LDEXPL])
87 dnl Append $ISNANL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates.
88 case " $EXP2L_LIBM " in
89 *" $ISNANL_LIBM "*) ;;
90 *) EXP2L_LIBM="$EXP2L_LIBM $ISNANL_LIBM" ;;
92 dnl Append $ROUNDL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates.
93 case " $EXP2L_LIBM " in
94 *" $ROUNDL_LIBM "*) ;;
95 *) EXP2L_LIBM="$EXP2L_LIBM $ROUNDL_LIBM" ;;
97 dnl Append $LDEXPL_LIBM to EXP2L_LIBM, avoiding gratuitous duplicates.
98 case " $EXP2L_LIBM " in
99 *" $LDEXPL_LIBM "*) ;;
100 *) EXP2L_LIBM="$EXP2L_LIBM $LDEXPL_LIBM" ;;
104 AC_SUBST([EXP2L_LIBM])