diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e8efead7ffd..ac76ef869bd 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2012-02-28  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR tree-optimization/53207
+	* doc/invoke.texi: Document as experimental and relying on graphite.
+
 2012-02-28  Georg-Johann Lay  <avr@gjlay.de>
 
 	* config/avr/avr-devices.c (avr_mcu_type): Adjust NULL part
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 7d4926abf3c..d69f1fb93dd 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -7289,8 +7289,12 @@ dead code elimination in loops.
 @item -floop-flatten
 @opindex floop-flatten
 Removes the loop nesting structure: transforms the loop nest into a
-single loop.  This transformation can be useful to vectorize all the
-levels of the loop nest.
+single loop.  This transformation can be useful as an enablement
+transform for vectorization and parallelization.  This feature
+is experimental.
+To use this code transformation, GCC has to be configured
+with @option{--with-ppl} and @option{--with-cloog} to enable the
+Graphite loop transformation infrastructure.
 
 @item -floop-parallelize-all
 @opindex floop-parallelize-all