On Wed, Apr 14, 2021 at 02:47:59PM -0500, Segher Boessenkool wrote:
> On Wed, Apr 14, 2021 at 09:45:35PM +0200, Jakub Jelinek wrote:
> > On Wed, Apr 14, 2021 at 02:42:54PM -0500, Segher Boessenkool wrote:
> > > > provably doesn't (that is from the splitter I wrote for the non-hard
> > > > regs),
> > > > nor
> > > > [(set (match_operand:GPI 0 "register_operand")
> > > > (LOGICAL:GPI
> > > > (and:GPI (ashift:GPI (match_operand:GPI 1 "register_operand")
> > > > (match_operand:QI 2
> > > > "aarch64_shift_imm_<mode>"))
> > > > (match_operand:GPI 3 "const_int_operand"))
> > > > (zero_extend:GPI (subreg (match_dup 1) 0))))]
> > > > works (and it is unclear how I'd find out the mode of the subreg even
> > > > if it
> > > > worked).
> > >
> > > Just
> > > (subreg:QI (match_dup 1) 0)
> > > should work?
> >
> > That doesn't work either.
>
> Why not? What goes wrong with that?
It just doesn't match and therefore doesn't split it.
Jakub
