See $subj. Committed.
* config/rl78/rl78.c (move_elim_pass): Don't optimize away
volatile memory references.
Index: config/rl78/rl78.c
===================================================================
--- config/rl78/rl78.c (revision 220150)
+++ config/rl78/rl78.c (working copy)
@@ -222,7 +222,12 @@
can eliminate the second SET. */
if (prev
&& rtx_equal_p (SET_DEST (prev), SET_SRC (set))
- && rtx_equal_p (SET_DEST (set), SET_SRC (prev)))
+ && rtx_equal_p (SET_DEST (set), SET_SRC (prev))
+ /* ... and none of the operands are volatile. */
+ && ! volatile_refs_p (SET_SRC (prev))
+ && ! volatile_refs_p (SET_DEST (prev))
+ && ! volatile_refs_p (SET_SRC (set))
+ && ! volatile_refs_p (SET_DEST (set)))
{
if (dump_file)
fprintf (dump_file, " Delete insn %d because it is redundant\n",
