[PATCH] Improve dump when SLP fails to compute lane extraction insertion points

[Richard Biener]

The following helps debugging.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

        * tree-vect-slp.cc (vect_bb_slp_mark_live_stmts): Enhance
        dumping in the failure case.
---
 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 0bae78678ca..63baa17d09d 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9129,7 +9129,8 @@ vect_bb_slp_mark_live_stmts (bb_vec_info bb_vinfo, 
slp_tree node,
                    if (dump_enabled_p ())
                      dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
                                       "Cannot determine insertion place for "
-                                      "lane extract\n");
+                                      "lane extract of %T at node %p\n",
+                                      DEF_FROM_PTR (def_p), (void *)node);
                    can_insert = false;
                    break;
                  }
-- 
2.51.0