tree-optimization/115652 - amend last fix

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.

	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.

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 1f5b3fccf41aa1efde0f91e1bb31dcfb39fc4038..1252b613125be86fdecf0344c4d9da9601684bee 100644 (file)
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9747,7 +9747,8 @@ 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;
              }
        }