On Tue, 16 Feb 2016, Jakub Jelinek wrote:
> On Mon, Feb 15, 2016 at 08:43:22PM +0100, Richard Biener wrote:
> > On February 15, 2016 7:15:35 PM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
> > wrote:
> > >On Mon, Feb 15, 2016 at 06:58:45PM +0100, Richard Biener wrote:
> > >> We could also force_reg those at expansion or apply
> > >SHIFT_COUNT_TRUNCATED to those invalid constants there.
> > >
> > >Sure, but for force_reg we'd still need the gen_int_mode anyway.
> > >As for SHIFT_COUNT_TRUNCATED, it should have been applied already from
> > >the
> > >caller - expand_shift_1.
> >
> > But then no out of bound values should remain.
> > Until we get 256bit ints where your workaround wouldn't work either?
>
> Of course it would work, because in that case mode would be OImode, not
> QImode, and thus the code would ensure the shift count is valid OImode
> constant.
Ah, yes - here we're still using op0 mode. For OImode wouldn't we
get a CONST_DOUBLE or CONST_WIDE_INT though?
> Anyway, the patch I've posted has been broken for vector shifts,
> the last argument to gen_int_mode should have been GET_MODE_INNER (mode).
>
> Here is a variant of that patch with force_reg, seems to work on
> aarch64 and x86_64.
Works for me.
Thanks,
Richard.
> 2016-02-16 Jakub Jelinek <ja...@redhat.com>
>
> PR rtl-optimization/69764
> PR rtl-optimization/69771
> * optabs.c (expand_binop): Ensure for shift optabs invalid CONST_INT
> op1 is valid for GET_MODE_INNER (mode) and force it into a reg.
>
> --- gcc/optabs.c.jj 2016-02-15 22:22:46.161674598 +0100
> +++ gcc/optabs.c 2016-02-16 08:20:01.206889067 +0100
> @@ -1125,6 +1125,16 @@ expand_binop (machine_mode mode, optab b
> op1 = negate_rtx (mode, op1);
> binoptab = add_optab;
> }
> + /* For shifts, constant invalid op1 might be expanded from different
> + mode than MODE. As those are invalid, force them to a register
> + to avoid further problems during expansion. */
> + else if (CONST_INT_P (op1)
> + && shift_optab_p (binoptab)
> + && UINTVAL (op1) >= GET_MODE_BITSIZE (GET_MODE_INNER (mode)))
> + {
> + op1 = gen_int_mode (INTVAL (op1), GET_MODE_INNER (mode));
> + op1 = force_reg (GET_MODE_INNER (mode), op1);
> + }
>
> /* Record where to delete back to if we backtrack. */
> last = get_last_insn ();
>
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
