+Thu Oct 25 12:21:58 2001 Jeffrey A Law (law@cygnus.com)
+
+ * doc/md.texi (movMM): Clarify semantics of storing into a
+ non-paradoxical SUBREG.
+
2001-10-25 Zack Weinberg <zack@codesourcery.com>
* langhooks.c (lang_hook_default_clear_binding_stack): New.
If operand 0 is a @code{subreg} with mode @var{m} of a register whose
own mode is wider than @var{m}, the effect of this instruction is
to store the specified value in the part of the register that corresponds
-to mode @var{m}. The effect on the rest of the register is undefined.
+to mode @var{m}. Bits outside of @var{m}, but which are within the
+same target word as the @code{subreg} are undefined. Bits which are
+outside the target word are left unchanged.
This class of patterns is special in several ways. First of all, each
of these names up to and including full word size @emph{must} be defined,