https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68917
--- Comment #2 from Chen Gang <gang.chen.5i5j at gmail dot com> ---
(In reply to Bernd Edlinger from comment #1)
> does something like this help?
>
Oh, sorry for replying late.
I shall try to give a test within this month.
Thanks. :-)
> Index: tilegx.md
> ===================================================================
> --- tilegx.md (Revision 231696)
> +++ tilegx.md (Arbeitskopie)
> @@ -1799,13 +1799,16 @@
>
> (define_expand "clzsi2"
> [(set (match_dup 2)
> - (ashift:DI (match_operand:SI 1 "reg_or_0_operand" "")
> + (zero_extend:DI (match_operand:SI 1 "reg_or_0_operand" "")))
> + (set (match_dup 2)
> + (ashift:DI (match_dup 2)
> (const_int 32)))
> - (set (subreg:DI (match_operand:SI 0 "register_operand" "") 0)
> - (clz:DI (match_dup 2)))]
> + (set (match_dup 2)
> + (clz:DI (match_dup 2)))
> + (set (match_operand:SI 0 "register_operand" "")
> + (subreg:SI (match_dup 2) 0))]
> ""
> {
> - operands[1] = simplify_gen_subreg (DImode, operands[1], SImode, 0);
> operands[2] = gen_reg_rtx (DImode);
> })
