Hi!
On Fri, Feb 17, 2023 at 05:55:04PM +0800, Kewen.Lin wrote:
> As PR108807 exposes, the current handling in function
> rs6000_expand_vector_set_var_p9 doesn't take care of big
> endianness. Currently the function is to rotate the
> target vector by moving element to-be-set to element 0,
> set element 0 with the given val, then rotate back. To
> get the permutation control vector for the rotation, it
> makes use of lvsr and lvsl, but the element ordering is
> different for BE and LE (like element 0 is the most
> significant one on BE while the least significant one on
> LE), this patch is to add consideration for BE and make
> sure permutation control vectors for rotations are expected.
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -7235,22 +7235,26 @@ rs6000_expand_vector_set_var_p9 (rtx target, rtx val,
> rtx idx)
>
> machine_mode shift_mode;
> rtx (*gen_ashl)(rtx, rtx, rtx);
> - rtx (*gen_lvsl)(rtx, rtx);
> - rtx (*gen_lvsr)(rtx, rtx);
> + rtx (*gen_pcvr1)(rtx, rtx);
> + rtx (*gen_pcvr2)(rtx, rtx);
Space before "(" btw, you can fix that at the same time? :-)
What does "pcvr" mean? You could put that in a short comment?
> + /* Generate one permutation control vector used for rotating the element
Ah. Yeah just "/* Permutation control vector */" for the above one
prevents all mysteries :-)
Patch looks good. Thanks!
Segher
