2 dnl Copyright (C) 2012-2017 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_HYPOTL],
9 m4_divert_text([DEFAULTS], [gl_hypotl_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
11 AC_REQUIRE([gl_FUNC_HYPOT])
13 dnl Persuade glibc <math.h> to declare hypotl().
14 AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
16 dnl Test whether hypotl() exists. Assume that hypotl(), if it exists, is
17 dnl defined in the same library as hypot().
19 LIBS="$LIBS $HYPOT_LIBM"
20 AC_CHECK_FUNCS([hypotl])
22 if test $ac_cv_func_hypotl = yes; then
23 HYPOTL_LIBM="$HYPOT_LIBM"
26 LIBS="$LIBS $HYPOTL_LIBM"
29 case "$gl_cv_func_hypotl_works" in
31 *) REPLACE_HYPOTL=1 ;;
34 m4_ifdef([gl_FUNC_HYPOTL_IEEE], [
35 if test $gl_hypotl_required = ieee && test $REPLACE_HYPOTL = 0; then
36 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
37 AC_CACHE_CHECK([whether hypotl works according to ISO C 99 with IEC 60559],
38 [gl_cv_func_hypotl_ieee],
41 LIBS="$LIBS $HYPOTL_LIBM"
44 #ifndef __NO_MATH_INLINES
45 # define __NO_MATH_INLINES 1 /* for glibc */
48 /* Compare two numbers with ==.
49 This is a separate function because IRIX 6.5 "cc -O" miscompiles an
52 numeric_equal (long double x, long double y)
56 static long double dummy (long double x, long double y) { return 0; }
58 long double one = 1.0L;
59 int main (int argc, char *argv[])
61 long double (*my_hypotl) (long double, long double) = argc ? hypotl : dummy;
63 /* Test hypotl(NaN,Infinity).
64 This test fails on OSF/1 5.1 and native Windows. */
65 f = my_hypotl (zero / zero, one / zero);
66 if (!numeric_equal (f, f))
71 [gl_cv_func_hypotl_ieee=yes],
72 [gl_cv_func_hypotl_ieee=no],
74 # Guess yes on glibc systems.
75 *-gnu*) gl_cv_func_hypotl_ieee="guessing yes" ;;
76 # If we don't know, assume the worst.
77 *) gl_cv_func_hypotl_ieee="guessing no" ;;
82 case "$gl_cv_func_hypotl_ieee" in
84 *) REPLACE_HYPOTL=1 ;;
90 dnl If the function is declared but does not appear to exist, it may be
91 dnl defined as an inline function. In order to avoid a conflict, we have
92 dnl to define rpl_hypotl, not hypotl.
93 AC_CHECK_DECLS([hypotl], [REPLACE_HYPOTL=1], , [[#include <math.h>]])
95 if test $HAVE_HYPOTL = 0 || test $REPLACE_HYPOTL = 1; then
96 dnl Find libraries needed to link lib/hypotl.c.
97 if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
98 HYPOTL_LIBM="$HYPOT_LIBM"
100 AC_REQUIRE([gl_FUNC_FABSL])
101 AC_REQUIRE([gl_FUNC_FREXPL])
102 AC_REQUIRE([gl_FUNC_LDEXPL])
103 AC_REQUIRE([gl_FUNC_SQRTL])
105 dnl Append $FABSL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates.
106 case " $HYPOTL_LIBM " in
107 *" $FABSL_LIBM "*) ;;
108 *) HYPOTL_LIBM="$HYPOTL_LIBM $FABSL_LIBM" ;;
110 dnl Append $FREXPL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates.
111 case " $HYPOTL_LIBM " in
112 *" $FREXPL_LIBM "*) ;;
113 *) HYPOTL_LIBM="$HYPOTL_LIBM $FREXPL_LIBM" ;;
115 dnl Append $LDEXPL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates.
116 case " $HYPOTL_LIBM " in
117 *" $LDEXPL_LIBM "*) ;;
118 *) HYPOTL_LIBM="$HYPOTL_LIBM $LDEXPL_LIBM" ;;
120 dnl Append $SQRTL_LIBM to HYPOTL_LIBM, avoiding gratuitous duplicates.
121 case " $HYPOTL_LIBM " in
122 *" $SQRTL_LIBM "*) ;;
123 *) HYPOTL_LIBM="$HYPOTL_LIBM $SQRTL_LIBM" ;;
127 AC_SUBST([HYPOTL_LIBM])
130 dnl Test whether hypotl() works.
131 dnl On OpenBSD 5.1/SPARC,
132 dnl hypotl (2.5541394760659556563446062497337725156L, 7.7893454113437840832487794525518765265L)
133 dnl has rounding errors that eat up the last 8 to 9 decimal digits.
134 AC_DEFUN([gl_FUNC_HYPOTL_WORKS],
136 AC_REQUIRE([AC_PROG_CC])
137 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
138 AC_CACHE_CHECK([whether hypotl works], [gl_cv_func_hypotl_works],
145 my_ldexpl (long double x, int d)
153 volatile long double x;
154 volatile long double y;
155 volatile long double z;
160 x = 2.5541394760659556563446062497337725156L;
161 y = 7.7893454113437840832487794525518765265L;
163 err = z * z - (x * x + y * y);
164 err = my_ldexpl (err, LDBL_MANT_DIG);
172 [gl_cv_func_hypotl_works=yes],
173 [gl_cv_func_hypotl_works=no],
175 openbsd*) gl_cv_func_hypotl_works="guessing no";;
176 *) gl_cv_func_hypotl_works="guessing yes";;