Make range_from_dom more effective.

Add modes to range_from_dom such that we can simply query, or adjust the
cache and deal with multiple predecessor blocks.

	* gimple-range-cache.cc (ranger_cache::ranger_cache): Start with
	worlist truncated.
	(ranger_cache::entry_range): Add rfd_mode parameter.
	(ranger_cache::exit_range): Ditto.
	(ranger_cache::edge_range): New.  Incorporate from range_on_edge.
	(ranger_cache::range_of_expr): Adjust call to entry_range.
	(ranger_cache::range_on_edge): Split to edge_range and call.
	(ranger_cache::fill_block_cache): Always invoke range_from_dom.
	(ranger_cache::range_from_dom): Make reentrant, add search mode, handle
	mutiple predecessors.
	(ranger_cache::update_to_nonnull): Adjust call to exit_range.
	* gimple-range-cache.h (ranger_cache): Add enum rfd_mode.  Adjust
	prototypes.

1 files changed, 10 insertions, 3 deletions

diff --git a/gcc/gimple-range-cache.h b/gcc/gimple-range-cache.h
index a0244e4..560403b 100644
--- a/gcc/gimple-range-cache.h
+++ b/gcc/gimple-range-cache.h
@@ -129,7 +129,6 @@ public:
   virtual bool range_of_expr (irange &r, tree name, gimple *stmt);
   virtual bool range_on_edge (irange &r, edge e, tree expr);
   bool block_range (irange &r, basic_block bb, tree name, bool calc = true);
-  bool range_from_dom (irange &r, tree name, basic_block bb);
 
   bool get_global_range (irange &r, tree name) const;
   bool get_global_range (irange &r, tree name, bool &current_p);
@@ -151,9 +150,17 @@ private:
   void fill_block_cache (tree name, basic_block bb, basic_block def_bb);
   void propagate_cache (tree name);
 
+  enum rfd_mode
+    {
+      RFD_NONE,		// Only look at current block cache.
+      RFD_READ_ONLY,	// Scan DOM tree, do not write to cache.
+      RFD_FILL		// Scan DOM tree, updating important nodes.
+    };
+  bool range_from_dom (irange &r, tree name, basic_block bb, enum rfd_mode);
   void range_of_def (irange &r, tree name, basic_block bb = NULL);
-  void entry_range (irange &r, tree expr, basic_block bb);
-  void exit_range (irange &r, tree expr, basic_block bb);
+  void entry_range (irange &r, tree expr, basic_block bb, enum rfd_mode);
+  void exit_range (irange &r, tree expr, basic_block bb, enum rfd_mode);
+  bool edge_range (irange &r, edge e, tree name, enum rfd_mode);
 
   vec<basic_block> m_workback;
   class update_list *m_update;