Reapply "Incrementally recompute dominators when inlining."

runtime/vm/flow_graph_builder.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_FLOW_GRAPH_BUILDER_H_
 #define VM_FLOW_GRAPH_BUILDER_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
 #include "vm/intermediate_language.h"
 
 namespace dart {
 
 class FlowGraph;
 class Instruction;
 class ParsedFunction;
 
 // An InliningContext collects the exits from an inlined function during
 // graph construction so they can be plugged into the caller's flow graph.
 class InliningContext: public ValueObject {
  public:
-  InliningContext() : exits_(4) { }
+  InliningContext(FlowGraph* caller_graph, Definition* call)
+      : caller_graph_(caller_graph), call_(call), exits_(4) { }
 
   void AddExit(ReturnInstr* exit);
 
   // Inline a flow graph at a call site.
   //
   // Assumes the callee graph was computed by BuildGraph with an inlining
   // context and transformed to SSA with ComputeSSA with a correct virtual
   // register number, and that the use lists have been correctly computed.
   //
-  // After inlining the caller graph will correctly have adjusted the
-  // pre/post orders, the dominator tree and the use lists.
-  void ReplaceCall(FlowGraph* caller_graph,
-                   Definition* call,
-                   FlowGraph* callee_graph);
+  // After inlining the caller graph will have correctly adjusted the use
+  // lists.  The block orders will need to be recomputed, and the dominator
+  // tree will need to be recomputed if it is marked invalid in the caller
+  // graph.
+  void ReplaceCall(FlowGraph* callee_graph);
 
  private:
   struct Data {
     BlockEntryInstr* exit_block;
     ReturnInstr* exit_return;
   };
 
-  static void PrepareGraphs(FlowGraph* caller_graph,
-                            Definition* call,
-                            FlowGraph* callee_graph);
+  void PrepareGraphs(FlowGraph* caller_graph);
 
   BlockEntryInstr* ExitBlockAt(intptr_t i) const {
     ASSERT(exits_[i].exit_block != NULL);
     return exits_[i].exit_block;
   }
   Instruction* LastInstructionAt(intptr_t i) const {
     return exits_[i].exit_return->previous();
   }
   Value* ValueAt(intptr_t i) const {
     return exits_[i].exit_return->value();
   }
 
   static int LowestBlockIdFirst(const Data* a, const Data* b);
   void SortExits();
 
+  Definition* JoinReturns(BlockEntryInstr** exit_block,
+                          Instruction** last_instruction);
+
+  FlowGraph* caller_graph_;
+  Definition* call_;
   GrowableArray<Data> exits_;
 };
 
 
 // Build a flow graph from a parsed function's AST.
 class FlowGraphBuilder: public ValueObject {
  public:
   // The inlining context is NULL if not inlining.
   FlowGraphBuilder(const ParsedFunction& parsed_function,
                    InliningContext* inlining_context);
@@ skipping 374 matching lines @@
   // Output parameters.
   GrowableArray<TargetEntryInstr**> true_successor_addresses_;
   GrowableArray<TargetEntryInstr**> false_successor_addresses_;
 
   intptr_t condition_token_pos_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_