Inline [] operator on one-byte strings.

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 20 matching lines @@
 // TODO(srdjan): Add _ByteArrayBase, get:length.
 
 #define RECOGNIZED_LIST(V)                                                     \
   V(_ObjectArray, get:length, ObjectArrayLength)                               \
   V(_ImmutableArray, get:length, ImmutableArrayLength)                         \
   V(_GrowableObjectArray, get:length, GrowableArrayLength)                     \
   V(_GrowableObjectArray, get:capacity, GrowableArrayCapacity)                 \
   V(_StringBase, get:length, StringBaseLength)                                 \
   V(_StringBase, get:isEmpty, StringBaseIsEmpty)                               \
   V(_StringBase, charCodeAt, StringBaseCharCodeAt)                             \
+  V(_StringBase, [], StringBaseCharAt)                                         \
   V(_IntegerImplementation, toDouble, IntegerToDouble)                         \
   V(_Double, toInt, DoubleToInteger)                                           \
   V(::, sqrt, MathSqrt)                                                        \
 
 // Class that recognizes the name and owner of a function and returns the
 // corresponding enum. See RECOGNIZED_LIST above for list of recognizable
 // functions.
 class MethodRecognizer : public AllStatic {
  public:
   enum Kind {
@@ skipping 206 matching lines @@
   M(MathSqrt)                                                                  \
   M(UnboxDouble)                                                               \
   M(BoxDouble)                                                                 \
   M(UnboxInteger)                                                              \
   M(BoxInteger)                                                                \
   M(BinaryMintOp)                                                              \
   M(ShiftMintOp)                                                               \
   M(UnaryMintOp)                                                               \
   M(CheckArrayBound)                                                           \
   M(Constraint)                                                                \
-  M(StringCharCodeAt)
+  M(StringCharCodeAt)                                                          \
+  M(StringFromCharCode)
 
 
 #define FORWARD_DECLARATION(type) class type##Instr;
 FOR_EACH_INSTRUCTION(FORWARD_DECLARATION)
 #undef FORWARD_DECLARATION
 
 
 // Functions required in all concrete instruction classes.
 #define DECLARE_INSTRUCTION(type)                                              \
   virtual Tag tag() const { return k##type; }                                  \
@@ skipping 2397 matching lines @@
 
   virtual bool AffectedBySideEffect() const { return true; }
 
  private:
   const intptr_t class_id_;
 
   DISALLOW_COPY_AND_ASSIGN(StringCharCodeAtInstr);
 };
 
 
+class StringFromCharCodeInstr : public TemplateDefinition<1> {
+ public:
+  explicit StringFromCharCodeInstr(Value* char_code) {
+    ASSERT(char_code != NULL);
+    ASSERT(char_code->definition()->IsStringCharCodeAt() &&
+           (char_code->definition()->AsStringCharCodeAt()->class_id() ==
+            kOneByteStringCid));
+    inputs_[0] = char_code;
+  }
+
+  DECLARE_INSTRUCTION(StringFromCharCode)
+  virtual RawAbstractType* CompileType() const;
+
+  Value* char_code() const { return inputs_[0]; }
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual bool HasSideEffect() const { return false; }
+
+  virtual intptr_t ResultCid() const;
+
+  virtual bool AttributesEqual(Instruction* other) const { return true; }
+
+  virtual bool AffectedBySideEffect() const { return false; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(StringFromCharCodeInstr);
+};
+
+
 class LoadIndexedInstr : public TemplateDefinition<2> {
  public:
   LoadIndexedInstr(Value* array, Value* index, intptr_t class_id)
       : class_id_(class_id) {
     ASSERT(array != NULL);
     ASSERT(index != NULL);
     inputs_[0] = array;
     inputs_[1] = index;
   }
 
@@ skipping 1546 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_