Index: configure.in
===================================================================
RCS file: /cvsroot/guile/guile/guile-core/configure.in,v
retrieving revision 1.240
diff -u -r1.240 configure.in
--- configure.in	21 Apr 2004 23:37:22 -0000	1.240
+++ configure.in	23 May 2004 15:16:03 -0000
@@ -861,7 +861,17 @@
 #                                older systems
 #   sincos - GLIBC extension
 #
-AC_CHECK_FUNCS(asinh acosh atanh copysign finite isinf isnan sincos trunc)
+AC_CHECK_FUNCS(asinh acosh atanh copysign finite isnan sincos trunc)
+
+# On HP-UX 11, isinf() is a macro.  We must make sure that math.h is
+# included when checking for isinf().
+AC_MSG_CHECKING([for isinf])
+AC_LINK_IFELSE([AC_LANG_PROGRAM(
+ [[#include <math.h>]],
+ [[isinf (0.0);]])],
+ [AC_MSG_RESULT([yes])
+  AC_DEFINE(HAVE_ISINF, 1, [Define to 1 if you have the `isinf' function/macro.])],
+ [AC_MSG_RESULT([no])])
 
 # When testing for the presence of alloca, we need to add alloca.o
 # explicitly to LIBOBJS to make sure that it is translated to