+ m4_ifdef([gl_FUNC_FMODL_IEEE], [
+ if test $gl_fmodl_required = ieee && test $REPLACE_FMODL = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether fmodl works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_fmodl_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $FMODL_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (long double x, long double y)
+{
+ return x == y;
+}
+static long double dummy (long double x, long double y) { return 0; }
+int main (int argc, char *argv[])
+{
+ long double (*my_fmodl) (long double, long double) = argc ? fmodl : dummy;
+ long double f;
+ /* Test fmodl(...,0.0L).
+ This test fails on OSF/1 5.1. */
+ f = my_fmodl (2.0L, 0.0L);
+ if (numeric_equal (f, f))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_fmodl_ieee=yes],
+ [gl_cv_func_fmodl_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_fmodl_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_fmodl_ieee="guessing no" ;;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_fmodl_ieee" in
+ *yes) ;;
+ *) REPLACE_FMODL=1 ;;
+ esac
+ fi
+ ])