-# hypotl.m4 serial 1
-dnl Copyright (C) 2012 Free Software Foundation, Inc.
+# hypotl.m4 serial 5
+dnl Copyright (C) 2012-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_HYPOTL],
[
+ m4_divert_text([DEFAULTS], [gl_hypotl_required=plain])
AC_REQUIRE([gl_MATH_H_DEFAULTS])
AC_REQUIRE([gl_FUNC_HYPOT])
+ dnl Persuade glibc <math.h> to declare hypotl().
+ AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
dnl Test whether hypotl() exists. Assume that hypotl(), if it exists, is
dnl defined in the same library as hypot().
save_LIBS="$LIBS"
LIBS="$save_LIBS"
if test $ac_cv_func_hypotl = yes; then
HYPOTL_LIBM="$HYPOT_LIBM"
+
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $HYPOTL_LIBM"
+ gl_FUNC_HYPOTL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_hypotl_works" in
+ *yes) ;;
+ *) REPLACE_HYPOTL=1 ;;
+ esac
+
+ m4_ifdef([gl_FUNC_HYPOTL_IEEE], [
+ if test $gl_hypotl_required = ieee && test $REPLACE_HYPOTL = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether hypotl works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_hypotl_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $HYPOTL_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (long double x, long double y)
+{
+ return x == y;
+}
+static long double dummy (long double x, long double y) { return 0; }
+long double zero;
+long double one = 1.0L;
+int main (int argc, char *argv[])
+{
+ long double (*my_hypotl) (long double, long double) = argc ? hypotl : dummy;
+ long double f;
+ /* Test hypotl(NaN,Infinity).
+ This test fails on OSF/1 5.1 and native Windows. */
+ f = my_hypotl (zero / zero, one / zero);
+ if (!numeric_equal (f, f))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_hypotl_ieee=yes],
+ [gl_cv_func_hypotl_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_hypotl_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_hypotl_ieee="guessing no" ;;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_hypotl_ieee" in
+ *yes) ;;
+ *) REPLACE_HYPOTL=1 ;;
+ esac
+ fi
+ ])
else
HAVE_HYPOTL=0
+ fi
+ if test $HAVE_HYPOTL = 0 || test $REPLACE_HYPOTL = 1; then
dnl Find libraries needed to link lib/hypotl.c.
if test $HAVE_SAME_LONG_DOUBLE_AS_DOUBLE = 1; then
HYPOTL_LIBM="$HYPOT_LIBM"
fi
AC_SUBST([HYPOTL_LIBM])
])
+
+dnl Test whether hypotl() works.
+dnl On OpenBSD 5.1/SPARC,
+dnl hypotl (2.5541394760659556563446062497337725156L, 7.7893454113437840832487794525518765265L)
+dnl has rounding errors that eat up the last 8 to 9 decimal digits.
+AC_DEFUN([gl_FUNC_HYPOTL_WORKS],
+[
+ AC_REQUIRE([AC_PROG_CC])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether hypotl works], [gl_cv_func_hypotl_works],
+ [
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <float.h>
+#include <math.h>
+static long double
+my_ldexpl (long double x, int d)
+{
+ for (; d > 0; d--)
+ x *= 2.0L;
+ for (; d < 0; d++)
+ x *= 0.5L;
+ return x;
+}
+volatile long double x;
+volatile long double y;
+volatile long double z;
+int main ()
+{
+ long double err;
+
+ x = 2.5541394760659556563446062497337725156L;
+ y = 7.7893454113437840832487794525518765265L;
+ z = hypotl (x, y);
+ err = z * z - (x * x + y * y);
+ err = my_ldexpl (err, LDBL_MANT_DIG);
+ if (err < 0)
+ err = - err;
+ if (err > 1000.0L)
+ return 1;
+ return 0;
+}
+]])],
+ [gl_cv_func_hypotl_works=yes],
+ [gl_cv_func_hypotl_works=no],
+ [case "$host_os" in
+ openbsd*) gl_cv_func_hypotl_works="guessing no";;
+ *) gl_cv_func_hypotl_works="guessing yes";;
+ esac
+ ])
+ ])
+])