diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index dd7b0b68a72..889e326d324 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2010-02-08  Joern Rennecke  <joern.rennecke@embecosm.com>
+
+	* doc/tm.texi (TARGET_UNWIND_WORD_MODE): Document.
+
 2010-02-07  Adam Nemet  <adambnmet@gmail.com>
 
 	* config/mips/mips.md (*<optab>_trunc<mode>_exts): Fix comment
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index e69b0e16b75..aae27c5f049 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -1424,6 +1424,11 @@ of shift instructions expanded to libgcc calls.  If not defined
 targets.
 @end deftypefn
 
+@deftypefn {Target Hook} {enum machine_mode} TARGET_UNWIND_WORD_MODE (void)
+Return machine mode to be used for @code{_Unwind_Word} type.
+The default is to use @code{word_mode}.
+@end deftypefn
+
 @defmac ROUND_TOWARDS_ZERO
 If defined, this macro should be true if the prevailing rounding
 mode is towards zero.