From 6293272e9a47e6e7debe4acd8195a2ae2d9ef0df Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Wed, 16 Oct 2024 11:37:31 +0200
Subject: [PATCH] Fix gcc.dg/vect/vect-early-break_39.c FAIL with forced SLP
The testcases shows single-element interleaving of size three
being exempted from permutation lowering via heuristics
(see also PR116973). But it wasn't supposed to apply to
non-power-of-two sizes so this amends the check to ensure
the sub-group is aligned even when the number of lanes is one.
* tree-vect-slp.cc (vect_lower_load_permutations): Avoid
exempting non-power-of-two group sizes from lowering.
---
gcc/tree-vect-slp.cc | 1 +
1 file changed, 1 insertion(+)
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 629c4b433ab5..d35c2ea02dce 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -4427,6 +4427,7 @@ vect_lower_load_permutations (loop_vec_info loop_vinfo,
&& contiguous
&& (SLP_TREE_LANES (load) > 1 || loads.size () == 1)
&& pow2p_hwi (SLP_TREE_LANES (load))
+ && pow2p_hwi (group_lanes)
&& SLP_TREE_LOAD_PERMUTATION (load)[0] % SLP_TREE_LANES (load) == 0
&& group_lanes % SLP_TREE_LANES (load) == 0)
{
--
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