--- a/ChangeLog	Wed Dec 15 18:34:02 2004 +0000
+++ b/ChangeLog	Sat Dec 18 15:04:20 2004 +0000
@@ -1,3 +1,11 @@
+2004-12-17  John W. Eaton  <jwe@octave.org>
+
+	* configure.in: Use AC_GNU_SOURCE.
+
+2004-12-17  Orion Poplawski  <orion@cora.nwra.com>
+
+	* configure.in: Also check for signbit decl.
+
 2004-12-03  John W. Eaton  <jwe@octave.org>
 
 	* aclocal.m4 (OCTAVE_PROG_GPERF): Check with -L C++, not -L ANSI_C.

--- a/configure.in	Wed Dec 15 18:34:02 2004 +0000
+++ b/configure.in	Sat Dec 18 15:04:20 2004 +0000
@@ -29,7 +29,7 @@
 EXTERN_CXXFLAGS="$CXXFLAGS"
 
 AC_INIT
-AC_REVISION($Revision: 1.458 $)
+AC_REVISION($Revision: 1.459 $)
 AC_PREREQ(2.57)
 AC_CONFIG_SRCDIR([src/octave.cc])
 AC_CONFIG_HEADER(config.h)
@@ -38,6 +38,8 @@
   
 OCTAVE_HOST_TYPE
 
+AC_GNU_SOURCE
+
 AC_AIX
 AC_MINIX
 AC_ISC_POSIX
@@ -1153,6 +1155,7 @@
   ;;
   *)
     AC_CHECK_FUNCS(finite isnan isinf copysign signbit)
+    AC_CHECK_DECLS(signbit, , , [#include <math.h>])
   ;;
 esac
 

--- a/liboctave/ChangeLog	Wed Dec 15 18:34:02 2004 +0000
+++ b/liboctave/ChangeLog	Sat Dec 18 15:04:20 2004 +0000
@@ -1,3 +1,10 @@
+2004-12-17  John W. Eaton  <jwe@octave.org>
+
+	* lo-cieee.c (lo_ieee_signbit): New function.
+	* lo-ieee.h: Provide decl.
+	Don't define lo_ieee_signbit as a macro here.
+	From Orion Poplawski <orion@cora.nwra.com>.
+
 2004-11-18  John W. Eaton  <jwe@octave.org>
 
 	* int32NDArray.cc (pow): Delete instantiation.

--- a/liboctave/lo-cieee.c	Wed Dec 15 18:34:02 2004 +0000
+++ b/liboctave/lo-cieee.c	Sat Dec 18 15:04:20 2004 +0000
@@ -153,6 +153,30 @@
   return octave_NaN;
 }
 
+#if ! (defined (signbit) || defined (HAVE_DECL_SIGNBIT)) && defined (HAVE_SIGNBIT)
+extern int signbit (double);
+#endif
+
+int
+lo_ieee_signbit (double x)
+{
+/* In the following definitions, only check x < 0 explicitly to avoid
+   a function call when it looks like signbit or copysign are actually
+   functions.  */
+
+#if defined (signbit)
+  return signbit (x);
+#elif defined (HAVE_SIGNBIT)
+  return (x < 0 || signbit (x));
+#elif defined (copysign)
+  return (copysign (1.0, x) < 0);
+#elif defined (HAVE_COPYSIGN)
+  return (x < 0 || copysign (1.0, x) < 0);
+#else
+  return x < 0;
+#endif
+}
+
 /*
 ;;; Local Variables: ***
 ;;; mode: C++ ***

--- a/liboctave/lo-ieee.h	Wed Dec 15 18:34:02 2004 +0000
+++ b/liboctave/lo-ieee.h	Sat Dec 18 15:04:20 2004 +0000
@@ -66,24 +66,7 @@
 extern double lo_ieee_na_value (void);
 extern double lo_ieee_nan_value (void);
 
-/* In the following definitions, only check x < 0 explicitly to avoid
-   a function call when it looks like signbit or copysign are actually
-   functions.  */
-
-#if defined (signbit)
-#define lo_ieee_signbit(x) signbit (x)
-#elif defined (HAVE_SIGNBIT)
-#if defined (__MINGW32__)
-extern int signbit (double);
-#endif
-#define lo_ieee_signbit(x) (x < 0 || signbit (x))
-#elif defined (copysign)
-#define lo_ieee_signbit(x) (copysign (1.0, x) < 0)
-#elif defined (HAVE_COPYSIGN)
-#define lo_ieee_signbit(x) (x < 0 || copysign (1.0, x) < 0)
-#else
-#define lo_ieee_signbit(x) 0
-#endif
+extern int lo_ieee_signbit (double);
 
 #ifdef	__cplusplus
 }