https://gcc.gnu.org/g:8cae7cc099f533b2882898dc05528fcbb70ea9f2
commit r16-2658-g8cae7cc099f533b2882898dc05528fcbb70ea9f2
Author: Richard Biener <rguent...@suse.de>
Date: Wed Jul 30 15:05:19 2025 +0200
Disallow scan-store vectorization in epilogues
The following disallows vectorizing epilogues containing scan-stores.
Since code generation works by walking gimple stmts it is not ready
for this when cleaning up epilogue vectorization. I believe
scan-store vectorization needs most of the work done during SLP
discovery to reflect the data flow.
* tree-vect-stmts.cc (check_scan_store): Remove redundant
slp_node check. Disallow epilogue vectorization.
Diff:
---
gcc/tree-vect-stmts.cc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 88a12a1e3189..47a6b6c55893 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -7098,13 +7098,14 @@ check_scan_store (vec_info *vinfo, stmt_vec_info
stmt_info, tree vectype,
tree ref_type;
gcc_assert (STMT_VINFO_SIMD_LANE_ACCESS_P (stmt_info) > 1);
- if ((slp_node && SLP_TREE_LANES (slp_node) > 1)
+ if (SLP_TREE_LANES (slp_node) > 1
|| mask
|| memory_access_type != VMAT_CONTIGUOUS
|| TREE_CODE (DR_BASE_ADDRESS (dr_info->dr)) != ADDR_EXPR
|| !VAR_P (TREE_OPERAND (DR_BASE_ADDRESS (dr_info->dr), 0))
|| loop_vinfo == NULL
|| LOOP_VINFO_FULLY_MASKED_P (loop_vinfo)
+ || LOOP_VINFO_EPILOGUE_P (loop_vinfo)
|| STMT_VINFO_GROUPED_ACCESS (stmt_info)
|| !integer_zerop (get_dr_vinfo_offset (vinfo, dr_info))
|| !integer_zerop (DR_INIT (dr_info->dr))
