[PATCH] Assert we properly soft-fail SLP nodes during discovery

[Richard Biener]

With delaying soft-failing of SLP discovery we should make sure
the SLP discovery cache never ends up with non-failed nodes that
would need splitting.

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

        * tree-vect-slp.cc (vect_build_slp_tree): Assert successful
        discovered nodes do not require splitting.
---
 gcc/tree-vect-slp.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 88368b5b86c..3f88449cd1d 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -2030,6 +2030,10 @@ vect_build_slp_tree (vec_info *vinfo,
       gcc_assert (res_ == res);
       /* Keep a reference for the bst_map use.  */
       SLP_TREE_REF_COUNT (res)++;
+      /* For BB vectorization nodes that need splitting should be failed.  */
+      gcc_assert (!is_a <bb_vec_info> (vinfo)
+                 || multiple_p (group_size,
+                                TYPE_VECTOR_SUBPARTS (res->vectype)));
     }
   return res_;
 }
-- 
2.51.0