Simple iterative liveness analysis over SSA.

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"
@@ skipping 24 matching lines @@
 
   // Each try in this function gets its own try index.
   intptr_t AllocateTryIndex() { return ++last_used_try_index_; }
 
   // Manage the currently active try index.
   void set_try_index(intptr_t value) { try_index_ = value; }
   intptr_t try_index() const { return try_index_; }
 
   void AddCatchEntry(TargetEntryInstr* entry);
 
+  intptr_t current_ssa_temp_index() const {
+    return current_ssa_temp_index_;
+  }
+
  private:
   void ComputeDominators(GrowableArray<BlockEntryInstr*>* preorder,
                          GrowableArray<intptr_t>* parent,
                          GrowableArray<BitVector*>* dominance_frontier);
 
   void CompressPath(intptr_t start_index,
                     intptr_t current_index,
                     GrowableArray<intptr_t>* parent,
                     GrowableArray<intptr_t>* label);
 
@@ skipping 266 matching lines @@
   // Output parameters.
   TargetEntryInstr** true_successor_address_;
   TargetEntryInstr** false_successor_address_;
 
   intptr_t condition_token_index_;
 };
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_BUILDER_H_