On Wed, 22 May 2024, Manolis Tsamis wrote:
> The match.pd patterns to merge two vector permutes into one fail when a
> potentially no-op view convert expressions is between the two permutes.
> This change lifts this restriction.
>
> gcc/ChangeLog:
>
> * match.pd: Allow no-op view_convert between permutes.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/fold-perm-2.c: New test.
>
> Signed-off-by: Manolis Tsamis <manolis.tsa...@vrull.eu>
> ---
>
> gcc/match.pd | 14 ++++++++------
> gcc/testsuite/gcc.dg/fold-perm-2.c | 16 ++++++++++++++++
> 2 files changed, 24 insertions(+), 6 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/fold-perm-2.c
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 07e743ae464..cbb3c5d86e0 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -10039,19 +10039,21 @@ and,
> d = VEC_PERM_EXPR <a, b, NEW_VCST>; */
>
> (simplify
> - (vec_perm (vec_perm@0 @1 @2 VECTOR_CST@3) @0 VECTOR_CST@4)
> + (vec_perm (view_convert?@0 (vec_perm@1 @2 @3 VECTOR_CST@4)) @0 VECTOR_CST@5)
> (if (TYPE_VECTOR_SUBPARTS (type).is_constant ())
> (with
> {
> machine_mode result_mode = TYPE_MODE (type);
> - machine_mode op_mode = TYPE_MODE (TREE_TYPE (@1));
> + machine_mode op_mode = TYPE_MODE (TREE_TYPE (@2));
> int nelts = TYPE_VECTOR_SUBPARTS (type).to_constant ();
> vec_perm_builder builder0;
> vec_perm_builder builder1;
> vec_perm_builder builder2 (nelts, nelts, 1);
> }
> - (if (tree_to_vec_perm_builder (&builder0, @3)
> - && tree_to_vec_perm_builder (&builder1, @4))
> + (if (tree_to_vec_perm_builder (&builder0, @4)
> + && tree_to_vec_perm_builder (&builder1, @5)
> + && element_precision (TREE_TYPE (@0))
> + == element_precision (TREE_TYPE (@1)))
I think you want to check TYPE_SIZE (TREE_TYPE (@0/@1)) for equality
instead.
Otherwise OK.
Thanks,
Richard.
> (with
> {
> vec_perm_indices sel0 (builder0, 2, nelts);
> @@ -10073,10 +10075,10 @@ and,
> ? (!can_vec_perm_const_p (result_mode, op_mode, sel0, false)
> || !can_vec_perm_const_p (result_mode, op_mode, sel1, false))
> : !can_vec_perm_const_p (result_mode, op_mode, sel1, false)))
> - op0 = vec_perm_indices_to_tree (TREE_TYPE (@4), sel2);
> + op0 = vec_perm_indices_to_tree (TREE_TYPE (@5), sel2);
> }
> (if (op0)
> - (vec_perm @1 @2 { op0; })))))))
> + (view_convert (vec_perm @2 @3 { op0; }))))))))
>
> /* Merge
> c = VEC_PERM_EXPR <a, b, VCST0>;
> diff --git a/gcc/testsuite/gcc.dg/fold-perm-2.c
> b/gcc/testsuite/gcc.dg/fold-perm-2.c
> new file mode 100644
> index 00000000000..1a4ab4065de
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/fold-perm-2.c
> @@ -0,0 +1,16 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-fre1" } */
> +
> +typedef int veci __attribute__ ((vector_size (4 * sizeof (int))));
> +typedef unsigned int vecu __attribute__ ((vector_size (4 * sizeof (unsigned
> int))));
> +
> +void fun (veci *a, veci *b, veci *c)
> +{
> + veci r1 = __builtin_shufflevector (*a, *b, 0, 5, 2, 7);
> + vecu r2 = __builtin_convertvector (r1, vecu);
> + vecu r3 = __builtin_shufflevector (r2, r2, 2, 3, 1, 0);
> + *c = __builtin_convertvector (r3, veci);
> +}
> +
> +/* { dg-final { scan-tree-dump "VEC_PERM_EXPR.*{ 2, 7, 5, 0 }" "fre1" } } */
> +/* { dg-final { scan-tree-dump-times "VEC_PERM_EXPR" 1 "fre1" } } */
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)
