diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 94e8f94c18eb..4ad5bda34fc1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2004-12-03  Paolo Bonzini  <bonzini@gnu.org>
+
+	* doc/tm.texi (Misc): Document TARGET_FOLD_BUILTIN.
+
 2004-12-03  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* mklibgcc.in: Put back the default set of EXTRA_MULTILIB_PART.
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 788bc420fc62..dfc1878d69cf 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -9339,6 +9339,15 @@ ignored.  This function should return the result of the call to the
 built-in function.
 @end deftypefn
 
+@deftypefn {Target Hook} tree TARGET_FOLD_BUILTIN (tree @var{exp}, bool @var{ignore})
+
+Expand a call to a machine specific built-in function that was set up by
+@samp{TARGET_INIT_BUILTINS}.  @var{exp} is the expression for the
+function call; the result is another tree containing a simplified
+expression for the call's result.  If @var{ignore} is true the
+value will be ignored.
+@end deftypefn
+
 @defmac MD_CAN_REDIRECT_BRANCH (@var{branch1}, @var{branch2})
 
 Take a branch insn in @var{branch1} and another in @var{branch2}.