Merge from trunk revision 104c05c5284b7822d770ee51a7d91946c7e56d50.

1 files changed, 96 insertions, 11 deletions

diff --git a/gcc/tree-ssa-threadupdate.h b/gcc/tree-ssa-threadupdate.h
index 5f49b1a..94c9bc8 100644
--- a/gcc/tree-ssa-threadupdate.h
+++ b/gcc/tree-ssa-threadupdate.h
@@ -21,32 +21,114 @@ along with GCC; see the file COPYING3.  If not see
 #ifndef _TREE_SSA_THREADUPDATE_H
 #define _TREE_SSA_THREADUPDATE_H 1
 
-/* In tree-ssa-threadupdate.c.  */
-extern bool thread_through_all_blocks (bool);
 enum jump_thread_edge_type
 {
   EDGE_START_JUMP_THREAD,
-  EDGE_FSM_THREAD,
   EDGE_COPY_SRC_BLOCK,
   EDGE_COPY_SRC_JOINER_BLOCK,
   EDGE_NO_COPY_SRC_BLOCK
 };
 
+// We keep the registered jump threading opportunities in this
+// vector as edge pairs (original_edge, target_edge).
+
 class jump_thread_edge
 {
 public:
-  jump_thread_edge (edge e, enum jump_thread_edge_type type)
-    : e (e), type (type) {}
+  jump_thread_edge (edge e, jump_thread_edge_type t) : e (e), type (t) {}
 
   edge e;
-  enum jump_thread_edge_type type;
+  jump_thread_edge_type type;
+};
+
+class jump_thread_path_allocator
+{
+public:
+  jump_thread_path_allocator ();
+  ~jump_thread_path_allocator ();
+  jump_thread_edge *allocate_thread_edge (edge, jump_thread_edge_type);
+  vec<jump_thread_edge *> *allocate_thread_path ();
+private:
+  DISABLE_COPY_AND_ASSIGN (jump_thread_path_allocator);
+  obstack m_obstack;
+};
+
+// Abstract class for the jump thread registry.
+//
+// When all candidates have been registered with
+// register_jump_thread(), thread_through_all_blocks() is called to
+// update the CFG.
+
+class jt_path_registry
+{
+public:
+  jt_path_registry (bool backedge_threads);
+  virtual ~jt_path_registry ();
+  bool register_jump_thread (vec<jump_thread_edge *> *);
+  bool thread_through_all_blocks (bool peel_loop_headers);
+  jump_thread_edge *allocate_thread_edge (edge e, jump_thread_edge_type t);
+  vec<jump_thread_edge *> *allocate_thread_path ();
+  void debug ();
+protected:
+  void debug_path (FILE *, int pathno);
+  vec<vec<jump_thread_edge *> *> m_paths;
+  unsigned long m_num_threaded_edges;
+private:
+  virtual bool update_cfg (bool peel_loop_headers) = 0;
+  jump_thread_path_allocator m_allocator;
+  // True if threading through back edges is allowed.  This is only
+  // allowed in the generic copier in the backward threader.
+  bool m_backedge_threads;
+  DISABLE_COPY_AND_ASSIGN (jt_path_registry);
+};
+
+// Forward threader path registry using a custom BB copier.
+
+class fwd_jt_path_registry : public jt_path_registry
+{
+public:
+  fwd_jt_path_registry ();
+  ~fwd_jt_path_registry ();
+  void remove_jump_threads_including (edge);
+private:
+  bool update_cfg (bool peel_loop_headers) override;
+  void mark_threaded_blocks (bitmap threaded_blocks);
+  bool thread_block_1 (basic_block, bool noloop_only, bool joiners);
+  bool thread_block (basic_block, bool noloop_only);
+  bool thread_through_loop_header (class loop *loop,
+				   bool may_peel_loop_headers);
+  class redirection_data *lookup_redirection_data (edge e, enum insert_option);
+
+  hash_table<struct removed_edges> *m_removed_edges;
+
+  // Main data structure to hold information for duplicates of BB.
+  hash_table<redirection_data> *m_redirection_data;
+};
+
+// Backward threader path registry using a generic BB copier.
+
+class back_jt_path_registry : public jt_path_registry
+{
+public:
+  back_jt_path_registry ();
+private:
+  bool update_cfg (bool peel_loop_headers) override;
+  void adjust_paths_after_duplication (unsigned curr_path_num);
+  bool duplicate_thread_path (edge entry, edge exit, basic_block *region,
+			      unsigned n_region, unsigned current_path_no);
+  bool rewire_first_differing_edge (unsigned path_num, unsigned edge_num);
+};
+
+// Rather than search all the edges in jump thread paths each time DOM
+// is able to simply if control statement, we build a hash table with
+// the deleted edges.  We only care about the address of the edge, not
+// its contents.
+struct removed_edges : nofree_ptr_hash<edge_def>
+{
+  static hashval_t hash (edge e) { return htab_hash_pointer (e); }
+  static bool equal (edge e1, edge e2) { return e1 == e2; }
 };
 
-extern void register_jump_thread (vec <class jump_thread_edge *> *);
-extern void remove_jump_threads_including (edge);
-extern void delete_jump_thread_path (vec <class jump_thread_edge *> *);
-extern void remove_ctrl_stmt_and_useless_edges (basic_block, basic_block);
-extern void free_dom_edge_info (edge);
 extern unsigned int estimate_threading_killed_stmts (basic_block);
 
 enum bb_dom_status
@@ -61,4 +143,7 @@ enum bb_dom_status
 
 enum bb_dom_status determine_bb_domination_status (class loop *, basic_block);
 
+// In tree-ssa-dom.c.
+extern void free_dom_edge_info (edge);
+
 #endif