+dnl finite is BSD, isfinite is C99, so prefer the latter
+AC_CACHE_CHECK([whether isfinite is broken],[have_broken_isfinite],[
+AC_TRY_RUN([
+#ifdef HAVE_MATH_H
+#include <math.h>
+#endif
+#ifdef HAVE_FLOAT_H
+#include <float.h>
+#endif
+int main ()
+{
+#ifdef isfinite
+#ifdef LDBL_MAX
+ if (!isfinite(LDBL_MAX)) return 1;
+#endif
+#ifdef DBL_MAX
+ if (!isfinite(DBL_MAX)) return 1;
+#endif
+#endif
+return 0;
+}],[
+have_broken_isfinite=no],have_broken_isfinite=yes,[
+case "${target}" in
+ hppa*-*-hpux*) have_broken_isfinite=yes ;;
+ *) have_broken_isfinite=no ;;
+esac])
+])
+if test "x$have_broken_isfinite" = "xno"; then
+ AC_DEFINE(HAVE_ISFINITE)
+else
+AC_CHECK_FUNCS(finite,[],
+ [AC_CHECK_FUNCS(isfinite,[],
+ [AC_MSG_CHECKING(for isfinite with <math.h>)
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <math.h>
+volatile int x;volatile float f; ]],[[x = isfinite(f)]])],[AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_ISFINITE)],[AC_MSG_RESULT(no)])])])
+fi
+