2 dnl Copyright (C) 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_HYPOT],
9 m4_divert_text([DEFAULTS], [gl_hypot_required=plain])
10 AC_REQUIRE([gl_MATH_H_DEFAULTS])
12 dnl Determine HYPOT_LIBM.
13 gl_COMMON_DOUBLE_MATHFUNC([hypot])
15 m4_ifdef([gl_FUNC_HYPOT_IEEE], [
16 if test $gl_hypot_required = ieee && test $REPLACE_HYPOT = 0; then
17 AC_CACHE_CHECK([whether hypot works according to ISO C 99 with IEC 60559],
18 [gl_cv_func_hypot_ieee],
21 LIBS="$LIBS $HYPOT_LIBM"
24 #ifndef __NO_MATH_INLINES
25 # define __NO_MATH_INLINES 1 /* for glibc */
28 /* Compare two numbers with ==.
29 This is a separate function because IRIX 6.5 "cc -O" miscompiles an
32 numeric_equal (double x, double y)
36 static double dummy (double x, double y) { return 0; }
39 int main (int argc, char *argv[])
41 double (*my_hypot) (double, double) = argc ? hypot : dummy;
43 /* Test hypot(NaN,Infinity).
44 This test fails on OSF/1 5.1 and native Windows. */
45 f = my_hypot (zero / zero, one / zero);
46 if (!numeric_equal (f, f))
51 [gl_cv_func_hypot_ieee=yes],
52 [gl_cv_func_hypot_ieee=no],
53 [gl_cv_func_hypot_ieee="guessing no"])
56 case "$gl_cv_func_hypot_ieee" in
62 if test $REPLACE_HYPOT = 1; then
63 dnl Find libraries needed to link lib/hypot.c.
64 AC_REQUIRE([gl_FUNC_FABS])
65 AC_REQUIRE([gl_FUNC_FREXP])
66 AC_REQUIRE([gl_FUNC_LDEXP])
67 AC_REQUIRE([gl_FUNC_SQRT])
69 dnl Append $FABS_LIBM to HYPOT_LIBM, avoiding gratuitous duplicates.
70 case " $HYPOT_LIBM " in
72 *) HYPOT_LIBM="$HYPOT_LIBM $FABS_LIBM" ;;
74 dnl Append $FREXP_LIBM to HYPOT_LIBM, avoiding gratuitous duplicates.
75 case " $HYPOT_LIBM " in
77 *) HYPOT_LIBM="$HYPOT_LIBM $FREXP_LIBM" ;;
79 dnl Append $LDEXP_LIBM to HYPOT_LIBM, avoiding gratuitous duplicates.
80 case " $HYPOT_LIBM " in
82 *) HYPOT_LIBM="$HYPOT_LIBM $LDEXP_LIBM" ;;
84 dnl Append $SQRT_LIBM to HYPOT_LIBM, avoiding gratuitous duplicates.
85 case " $HYPOT_LIBM " in
87 *) HYPOT_LIBM="$HYPOT_LIBM $SQRT_LIBM" ;;