diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index bdec047edf3..aa49b15bad4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2007-02-23  DJ Delorie  <dj@redhat.com>
+
+	* doc/tm.h (BIGGEST_ALIGNMENT): Clarify the purpose of this macro.
+
 2007-02-23  Mike Stump  <mrs@apple.com>
 
 	* tlink.c (scan_linker_output): Parse linker messages from
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index ad179099869..4ebdcfb83b0 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -1068,7 +1068,9 @@ Alignment required for a function entry point, in bits.
 @end defmac
 
 @defmac BIGGEST_ALIGNMENT
-Biggest alignment that any data type can require on this machine, in bits.
+Biggest alignment that any data type can require on this machine, in
+bits.  Note that this is not the biggest alignment that is supported,
+just the biggest alignment that, when violated, may cause a fault.
 @end defmac
 
 @defmac MINIMUM_ATOMIC_ALIGNMENT