===================================================================
@@ -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",