Bootstrapped and tested on x86 and aarch64. This only assumes that the
mode of what simplify_replace_rtx returns is the same with its first
argument.
Thanks,
Manolis
On Tue, Nov 21, 2023 at 8:04 PM Manolis Tsamis <manolis.tsa...@vrull.eu> wrote:
>
> This code used to handle SUBREG for register replacement when ifcvt was doing
> the replacements manually. This special handling is not needed anymore
> because simplify_replace_rtx is used for the replacements and it properly
> handles these cases.
>
> gcc/ChangeLog:
>
> * ifcvt.cc (noce_convert_multiple_sets_1): Remove old code.
>
> Signed-off-by: Manolis Tsamis <manolis.tsa...@vrull.eu>
> ---
>
> Changes in v2:
> - Made standalone patch.
>
> gcc/ifcvt.cc | 38 --------------------------------------
> 1 file changed, 38 deletions(-)
>
> diff --git a/gcc/ifcvt.cc b/gcc/ifcvt.cc
> index a0af553b9ff..be42609a848 100644
> --- a/gcc/ifcvt.cc
> +++ b/gcc/ifcvt.cc
> @@ -3492,44 +3492,6 @@ noce_convert_multiple_sets_1 (struct noce_if_info
> *if_info,
> if (if_info->then_else_reversed)
> std::swap (old_val, new_val);
>
> -
> - /* We allow simple lowpart register subreg SET sources in
> - bb_ok_for_noce_convert_multiple_sets. Be careful when processing
> - sequences like:
> - (set (reg:SI r1) (reg:SI r2))
> - (set (reg:HI r3) (subreg:HI (r1)))
> - For the second insn new_val or old_val (r1 in this example) will be
> - taken from the temporaries and have the wider mode which will not
> - match with the mode of the other source of the conditional move, so
> - we'll end up trying to emit r4:HI = cond ? (r1:SI) : (r3:HI).
> - Wrap the two cmove operands into subregs if appropriate to prevent
> - that. */
> -
> - if (!CONSTANT_P (new_val)
> - && GET_MODE (new_val) != GET_MODE (temp))
> - {
> - machine_mode src_mode = GET_MODE (new_val);
> - machine_mode dst_mode = GET_MODE (temp);
> - if (!partial_subreg_p (dst_mode, src_mode))
> - {
> - end_sequence ();
> - return false;
> - }
> - new_val = lowpart_subreg (dst_mode, new_val, src_mode);
> - }
> - if (!CONSTANT_P (old_val)
> - && GET_MODE (old_val) != GET_MODE (temp))
> - {
> - machine_mode src_mode = GET_MODE (old_val);
> - machine_mode dst_mode = GET_MODE (temp);
> - if (!partial_subreg_p (dst_mode, src_mode))
> - {
> - end_sequence ();
> - return false;
> - }
> - old_val = lowpart_subreg (dst_mode, old_val, src_mode);
> - }
> -
> /* Try emitting a conditional move passing the backend the
> canonicalized comparison. The backend is then able to
> recognize expressions like
> --
> 2.34.1
>
