https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94541
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|middle-end |target
--- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to H.J. Lu from comment #12)
>
> But
>
> (insn 13 12 14 3 (set (reg:SI 4 si)
> (subreg:SI (reg/v:DI 4 si [orig:85 b ] [85]) 0)) "y.i":14:14 67
> {*movsi_internal}
> (expr_list:REG_DEAD (reg/v:DI 4 si [orig:85 b ] [85])
> (nil)))
>
> isn't useless and shouldn't be removed.
It is useless because TARGET_TRULY_NOOP_TRUNCATION is true. So the problem is
you don't have a zero_extend in the RTL in the first place where you needed it
to be.
THIS IS NOT A BUG in the middle-end.
