diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 21d08056ee1..3630a10d720 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-11-13  Eric Botcazou  <ebotcazou@libertysurf.fr>
+
+	* doc/md.texi (constraints) <% modifier>: Mention that it is
+	useless when the two alternatives are strictly identical.
+
 2004-11-13  Richard Henderson  <rth@redhat.com>
 
 	* expmed.c (extract_split_bit_field): Temporarily disable call to
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index adf9fe5d195..9d7771c2770 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -1550,7 +1550,9 @@ instruction is defined:
 @end smallexample
 @end ifset
 GCC can only handle one commutative pair in an asm; if you use more,
-the compiler may fail.
+the compiler may fail.  Note that you need not use the modifier if
+the two alternatives are strictly identical; this would only waste
+time in the reload pass.
 
 @cindex @samp{#} in constraint
 @item #