+ dnl Also check whether it's declared.
+ dnl IRIX 6.5 has remainderl() in libm but doesn't declare it in <math.h>.
+ AC_CHECK_DECLS([remainderl], , [HAVE_DECL_REMAINDERL=0], [[#include <math.h>]])
+
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $REMAINDERL_LIBM"
+ gl_FUNC_REMAINDERL_WORKS
+ LIBS="$save_LIBS"
+ case "$gl_cv_func_remainderl_works" in
+ *yes) ;;
+ *) REPLACE_REMAINDERL=1 ;;
+ esac
+
+ m4_ifdef([gl_FUNC_REMAINDERL_IEEE], [
+ if test $gl_remainderl_required = ieee && test $REPLACE_REMAINDERL = 0; then
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CACHE_CHECK([whether remainderl works according to ISO C 99 with IEC 60559],
+ [gl_cv_func_remainderl_ieee],
+ [
+ save_LIBS="$LIBS"
+ LIBS="$LIBS $REMAINDERL_LIBM"
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#ifndef __NO_MATH_INLINES
+# define __NO_MATH_INLINES 1 /* for glibc */
+#endif
+#include <math.h>
+extern
+#ifdef __cplusplus
+"C"
+#endif
+long double remainderl (long double, long double);
+/* Compare two numbers with ==.
+ This is a separate function because IRIX 6.5 "cc -O" miscompiles an
+ 'x == x' test. */
+static int
+numeric_equal (long double x, long double y)
+{
+ return x == y;
+}
+static long double dummy (long double x, long double y) { return 0; }
+int main (int argc, char *argv[])
+{
+ long double (*my_remainderl) (long double, long double) = argc ? remainderl : dummy;
+ long double f;
+ /* Test remainderl(...,0.0L).
+ This test fails on OSF/1 5.1. */
+ f = my_remainderl (2.0L, 0.0L);
+ if (numeric_equal (f, f))
+ return 1;
+ return 0;
+}
+ ]])],
+ [gl_cv_func_remainderl_ieee=yes],
+ [gl_cv_func_remainderl_ieee=no],
+ [case "$host_os" in
+ # Guess yes on glibc systems.
+ *-gnu*) gl_cv_func_remainderl_ieee="guessing yes" ;;
+ # If we don't know, assume the worst.
+ *) gl_cv_func_remainderl_ieee="guessing no" ;;
+ esac
+ ])
+ LIBS="$save_LIBS"
+ ])
+ case "$gl_cv_func_remainderl_ieee" in
+ *yes) ;;
+ *) REPLACE_REMAINDERL=1 ;;
+ esac
+ fi
+ ])