Implement a simple register allocator that tries to keep instruction results in registers.

runtime/vm/intermediate_language.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_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 1235 matching lines @@
 
   DECLARE_COMPUTATION(CreateArray)
 
   intptr_t token_index() const { return token_index_; }
   intptr_t try_index() const { return try_index_; }
   intptr_t ElementCount() const { return elements_->length(); }
   Value* ElementAt(intptr_t i) const { return (*elements_)[i]; }
   Value* element_type() const { return inputs_[0]; }
 
   virtual intptr_t InputCount() const;
-  virtual Value* InputAt(intptr_t i) const { return ElementAt(i); }
+  virtual Value* InputAt(intptr_t i) const;
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
  private:
   const intptr_t token_index_;
   const intptr_t try_index_;
   ZoneGrowableArray<Value*>* const elements_;
 
   DISALLOW_COPY_AND_ASSIGN(CreateArrayComp);
 };
@@ skipping 1153 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_