Copy propagated type info when inserting conversion.

runtime/vm/intermediate_language.h

 // Copyright (c) 2013, 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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 206 matching lines @@
     void Advance() {
       // Pre-fetch next on advance and cache it.
       current_ = next_;
       if (next_ != NULL) next_ = next_->next_use();
     }
    private:
     Value* current_;
     Value* next_;
   };
 
-  explicit Value(Definition* definition)
+  explicit Value(Definition* definition, CompileType* type = NULL)
       : definition_(definition),
         previous_use_(NULL),
         next_use_(NULL),
         instruction_(NULL),
         use_index_(-1),
-        reaching_type_(NULL) { }
+        reaching_type_(type) { }
 
   Definition* definition() const { return definition_; }
   void set_definition(Definition* definition) { definition_ = definition; }
 
   Value* previous_use() const { return previous_use_; }
   void set_previous_use(Value* previous) { previous_use_ = previous; }
 
   Value* next_use() const { return next_use_; }
   void set_next_use(Value* next) { next_use_ = next; }
 
   Instruction* instruction() const { return instruction_; }
   void set_instruction(Instruction* instruction) { instruction_ = instruction; }
 
   intptr_t use_index() const { return use_index_; }
   void set_use_index(intptr_t index) { use_index_ = index; }
 
   static void AddToList(Value* value, Value** list);
   void RemoveFromUseList();
 
-  Value* Copy() { return new Value(definition_); }
+  Value* Copy() {return new Value(definition_); }
+
+  Value* CopyWithType() {return new Value(definition_, reaching_type_); }

[Vyacheslav Egorov (Google), 2013/02/19 14:45:49]

Please add a comment here that CopyWithType should only be used when one can
guarantee that it'll not be hoisted beyound the guard that guaranteed reaching
type.

[Florian Schneider, 2013/02/19 15:02:06]

Done.

 
   CompileType* Type();
 
   void SetReachingType(CompileType* type) {
     reaching_type_ = type;
   }
 
   void PrintTo(BufferFormatter* f) const;
 
   const char* DebugName() const { return "Value"; }
@@ skipping 4200 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_