Box values of LoadCodeUnits that fall outside of smi range on 32bit platforms.

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 3683 matching lines @@
 // TODO(zerny): Add support for loading into UnboxedInt32x4.
 class LoadCodeUnitsInstr : public TemplateDefinition<2, NoThrow> {
  public:
   LoadCodeUnitsInstr(Value* str,
                      Value* index,
                      intptr_t element_count,
                      intptr_t class_id,
                      intptr_t token_pos)
       : class_id_(class_id),
         token_pos_(token_pos),
-        element_count_(element_count) {
+        element_count_(element_count),
+        representation_(kTagged) {
     ASSERT(element_count == 1 || element_count == 2 || element_count == 4);
     ASSERT(class_id == kOneByteStringCid || class_id == kTwoByteStringCid);
     SetInputAt(0, str);
     SetInputAt(1, index);
   }
 
   intptr_t token_pos() const { return token_pos_; }
 
   DECLARE_INSTRUCTION(LoadCodeUnits)
   virtual CompileType ComputeType() const;
 
   bool IsExternal() const {
     return array()->definition()->representation() == kUntagged;
   }
 
   Value* array() const { return inputs_[0]; }
   Value* index() const { return inputs_[1]; }
   intptr_t index_scale() const { return Instance::ElementSizeFor(class_id_); }
   intptr_t class_id() const { return class_id_; }
   intptr_t element_count() const { return element_count_; }
 
   bool can_pack_into_smi() const {
     return element_count() <= kSmiBits / (index_scale() * kBitsPerByte);
   }
 
   virtual bool CanDeoptimize() const { return false; }
 
-  virtual Representation representation() const;
+  virtual Representation representation() const { return representation_; }
+  void set_representation(Representation repr) { representation_ = repr; }
   virtual void InferRange(RangeAnalysis* analysis, Range* range);
 
   virtual EffectSet Effects() const { return EffectSet::None(); }
 
  private:
   const intptr_t class_id_;
   const intptr_t token_pos_;
   const intptr_t element_count_;
+  Representation representation_;
 
   DISALLOW_COPY_AND_ASSIGN(LoadCodeUnitsInstr);
 };
 
 
 class StringFromCharCodeInstr : public TemplateDefinition<1, NoThrow, Pure> {
  public:
   StringFromCharCodeInstr(Value* char_code, intptr_t cid) : cid_(cid) {
     ASSERT(char_code != NULL);
     ASSERT(char_code->definition()->IsLoadIndexed());
@@ skipping 4226 matching lines @@
       Isolate* isolate, bool opt) const {                                     \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_