Separate the array/string .length load from the bounds check.

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 3090 matching lines @@
   virtual void InferRange();
 
   void set_recognized_kind(MethodRecognizer::Kind kind) {
     recognized_kind_ = kind;
   }
 
   MethodRecognizer::Kind recognized_kind() const {
     return recognized_kind_;
   }
 
+  bool IsImmutableLengthLoad() const;
+
+  virtual Definition* Canonicalize(FlowGraphOptimizer* optimizer);
+
+  static MethodRecognizer::Kind RecognizedKindFromArrayCid(intptr_t cid);
+
  private:
   const intptr_t offset_in_bytes_;
   const AbstractType& type_;
   intptr_t result_cid_;
   const bool immutable_;
 
   MethodRecognizer::Kind recognized_kind_;
 
   DISALLOW_COPY_AND_ASSIGN(LoadFieldInstr);
 };
@@ skipping 1080 matching lines @@
 
   Value* value() const { return inputs_[0]; }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CheckSmiInstr);
 };
 
 
 class CheckArrayBoundInstr : public TemplateInstruction<2> {
  public:
-  CheckArrayBoundInstr(Value* array,
+  CheckArrayBoundInstr(Value* length,
                        Value* index,
                        intptr_t array_type,
                        InstanceCallInstr* instance_call)
       : array_type_(array_type) {
-    ASSERT(array != NULL);
+    ASSERT(length != NULL);
     ASSERT(index != NULL);
-    inputs_[0] = array;
+    inputs_[0] = length;
     inputs_[1] = index;
     deopt_id_ = instance_call->deopt_id();
   }
 
   DECLARE_INSTRUCTION(CheckArrayBound)
   virtual RawAbstractType* CompileType() const;
 
   virtual intptr_t ArgumentCount() const { return 0; }
 
   virtual bool CanDeoptimize() const { return true; }
 
   virtual bool HasSideEffect() const { return false; }
 
   virtual bool AttributesEqual(Instruction* other) const;
 
   virtual bool AffectedBySideEffect() const { return false; }
 
-  Value* array() const { return inputs_[0]; }
+  Value* length() const { return inputs_[0]; }
   Value* index() const { return inputs_[1]; }
 
   intptr_t array_type() const { return array_type_; }
 
   bool IsRedundant(RangeBoundary length);
 
   // Returns the length offset for array and string types.
   static intptr_t LengthOffsetFor(intptr_t class_id);
 
   static bool IsFixedLengthArrayType(intptr_t class_id);
@@ skipping 223 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_