Optimize one byte string comparisons.

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 651 matching lines @@
   M(UnboxFloat32x4)                                                            \
   M(BoxInt32x4)                                                                \
   M(UnboxInt32x4)                                                              \
   M(UnboxInteger)                                                              \
   M(BoxInteger)                                                                \
   M(BinaryMintOp)                                                              \
   M(ShiftMintOp)                                                               \
   M(UnaryMintOp)                                                               \
   M(CheckArrayBound)                                                           \
   M(Constraint)                                                                \
+  M(StringToCharCode)                                                          \
   M(StringFromCharCode)                                                        \
   M(StringInterpolate)                                                         \
   M(InvokeMathCFunction)                                                       \
   M(MergedMath)                                                                \
   M(GuardField)                                                                \
   M(IfThenElse)                                                                \
   M(BinaryFloat32x4Op)                                                         \
   M(Simd32x4Shuffle)                                                           \
   M(Simd32x4ShuffleMix)                                                        \
   M(Simd32x4GetSignMask)                                                       \
@@ skipping 3008 matching lines @@
 
   virtual bool MayThrow() const { return false; }
 
  private:
   const intptr_t cid_;
 
   DISALLOW_COPY_AND_ASSIGN(StringFromCharCodeInstr);
 };
 
 
+class StringToCharCodeInstr : public TemplateDefinition<1> {
+ public:
+  StringToCharCodeInstr(Value* str, intptr_t cid) : cid_(cid) {
+    ASSERT(str != NULL);
+    SetInputAt(0, str);
+  }
+
+  DECLARE_INSTRUCTION(StringToCharCode)
+  virtual CompileType ComputeType() const;
+
+  Value* str() const { return inputs_[0]; }
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual bool AllowsCSE() const { return true; }
+  virtual EffectSet Effects() const { return EffectSet::None(); }
+  virtual EffectSet Dependencies() const { return EffectSet::None(); }
+  virtual bool AttributesEqual(Instruction* other) const {
+    return other->AsStringToCharCode()->cid_ == cid_;
+  }
+
+  virtual bool MayThrow() const { return false; }
+
+ private:
+  const intptr_t cid_;
+
+  DISALLOW_COPY_AND_ASSIGN(StringToCharCodeInstr);
+};
+
+
 class StringInterpolateInstr : public TemplateDefinition<1> {
  public:
   StringInterpolateInstr(Value* value, intptr_t token_pos)
       : token_pos_(token_pos), function_(Function::Handle()) {
     SetInputAt(0, value);
   }
 
   Value* value() const { return inputs_[0]; }
   intptr_t token_pos() const { return token_pos_; }
 
@@ skipping 3344 matching lines @@
   ForwardInstructionIterator* current_iterator_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_