make a member an auto_sbitmap

gcc/ChangeLog:

2017-05-13  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* tree-ssa-dse.c (dse_dom_walker): Make m_live_byes a
	auto_sbitmap.

From-SVN: r248024

gcc/ChangeLog

 2017-05-13  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
 
+	* tree-ssa-dse.c (dse_dom_walker): Make m_live_byes a
+	auto_sbitmap.
+
+2017-05-13  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>
+
 	* df-core.c (df_set_blocks): Start using auto_bitmap.
 	(df_compact_blocks): Likewise.
 	* df-problems.c (df_rd_confluence_n): Likewise.

gcc/tree-ssa-dse.c

@@ -601,16 +601,14 @@ class dse_dom_walker : public dom_walker
 {
 public:
   dse_dom_walker (cdi_direction direction)
-    : dom_walker (direction), m_byte_tracking_enabled (false)
-
-  { m_live_bytes = sbitmap_alloc (PARAM_VALUE (PARAM_DSE_MAX_OBJECT_SIZE)); }
-
-  ~dse_dom_walker () { sbitmap_free (m_live_bytes); }
+    : dom_walker (direction),
+    m_live_bytes (PARAM_VALUE (PARAM_DSE_MAX_OBJECT_SIZE)),
+    m_byte_tracking_enabled (false) {}
 
   virtual edge before_dom_children (basic_block);
 
 private:
-  sbitmap m_live_bytes;
+  auto_sbitmap m_live_bytes;
   bool m_byte_tracking_enabled;
   void dse_optimize_stmt (gimple_stmt_iterator *);
 };