The previous fix breaks in the degenerate case when the discovered
last_stmt is equal to the first stmt in the block since then we
undo a required stmt advancement.
Bootstrap and regtest running on x86_64-unknown-linux-gnu.
PR tree-optimization/115652
* tree-vect-slp.cc (vect_schedule_slp_node): Only insert
at the start of the block if that strictly dominates
the discovered dependent stmt.
---
gcc/tree-vect-slp.cc | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 896ea6dc14c..ce214dd652e 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9752,7 +9752,8 @@ vect_schedule_slp_node (vec_info *vinfo,
{
gimple_stmt_iterator si2
= gsi_after_labels (LOOP_VINFO_LOOP (loop_vinfo)->header);
- if (vect_stmt_dominates_stmt_p (last_stmt, *si2))
+ if (last_stmt != *si2
+ && vect_stmt_dominates_stmt_p (last_stmt, *si2))
si = si2;
}
}
--
2.43.0
