------- Comment #7 from hjl dot tools at gmail dot com 2010-06-30 22:18 -------
(In reply to comment #6)
> Ok, thanks for investigating. I think we may need something like this:
>
> @@ -17574,6 +17574,7 @@ (define_peephole2
> || GET_MODE (operands[0]) == HImode))
> || GET_MODE (operands[0]) == SImode
> || (TARGET_64BIT && GET_MODE (operands[0]) == DImode))
> + && peep2_reg_dead_p (2, operands[0])
> /* We reorder load and the shift. */
> && !reg_overlap_mentioned_p (operands[0], operands[4])"
> [(set (match_dup 5) (match_dup 4))
>
> Testing now.
>
The old peepgole2 pattern has
/* The intermediate operand 0 must die or be same as output. */
&& (rtx_equal_p (operands[0], operands[5])
|| peep2_reg_dead_p (3, operands[0]))"
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44727
