[PATCH] Handle patterns as SLP roots of only live stmts

[Richard Biener]

gcc.dg/vect/vect-live-2.c shows it's important to handle live but
otherwise unused pattern stmts.

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

        * tree-vect-slp.cc (vect_analyze_slp): Lookup patterns when
        discovering from only-live roots.
---
 gcc/tree-vect-slp.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index c8af4d320eb..9c817de18bd 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -4723,6 +4723,7 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
            if (TREE_CODE (def) == SSA_NAME
                && !virtual_operand_p (def)
                && (stmt_info = loop_vinfo->lookup_def (def))
+               && ((stmt_info = vect_stmt_to_vectorize (stmt_info)), true)
                && STMT_VINFO_RELEVANT (stmt_info) == vect_used_only_live
                && STMT_VINFO_LIVE_P (stmt_info)
                && (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def
-- 
2.43.0