===================================================================
@@ -22456,6 +22456,10 @@
case GCC falls back to generating multiple accesses rather than code that
will fault or truncate the result at run time.
+Note: Due to restrictions of the C/C++11 memory model, write accesses are
+not allowed to touch non bit-field members. It is therefore recommended
+to define all bits of the field's type as bit-field members.
+
The default value of this option is determined by the application binary
interface for the target processor.