https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98694
--- Comment #6 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to Hongtao.liu from comment #5)
> and rewritten pattern
> (define_insn "*vec_dupv4hi"
> [(set (match_operand:V4HI 0 "register_operand" "=y,xYw")
> (vec_duplicate:V4HI
> (truncate:HI
> (match_operand:SI 1 "register_operand" "0,xYw"))))]
> to
>
> (define_insn "*vec_dupv4hi"
> [(set (match_operand:V4HI 0 "register_operand" "=y,xYw")
> (vec_duplicate:V4HI
> (vecTselect:HI
> (match_operand:V4HI 1 "register_operand" "0,xYw")
> (parallel [(const_int 0)]))))]
>
> could avoid this issue.
Oh, not workable.
---
if (MAYBE_SSE_CLASS_P (regclass) || MAYBE_MMX_CLASS_P (regclass))
{
/* Vector registers do not support QI or HImode loads. If we don't
disallow a change to these modes, reload will assume it's ok to
drop the subreg from (subreg:SI (reg:HI 100) 0). This affects
the vec_dupv4hi pattern. */
if (GET_MODE_SIZE (from) < 4)
return
---
