ARM native string addition.

src/arm/codegen-arm.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 519 matching lines @@
 #endif
 };
 
 
 class StringStubBase: public CodeStub {
  public:
   // Generate code for copying characters using a simple loop. This should only
   // be used in places where the number of characters is small and the
   // additional setup and checking in GenerateCopyCharactersLong adds too much
   // overhead. Copying of overlapping regions is not supported.
+  // Dest register ends at the position after the last character written.
   void GenerateCopyCharacters(MacroAssembler* masm,
                               Register dest,
                               Register src,
                               Register count,
                               Register scratch,
                               bool ascii);
 
   // Generate code for copying a large number of characters. This function
   // is allowed to spend extra time setting up conditions to make copying
   // faster. Copying of overlapping regions is not supported.
+  // Dest register ends at the position after the last character written.
   void GenerateCopyCharactersLong(MacroAssembler* masm,
                                   Register dest,
                                   Register src,
                                   Register count,
                                   Register scratch1,
                                   Register scratch2,
                                   Register scratch3,
                                   Register scratch4,
                                   Register scratch5,
                                   int flags);
 };
 
 
 // Flag that indicates how to generate code for the stub StringAddStub.
 enum StringAddFlags {
   NO_STRING_ADD_FLAGS = 0,
   NO_STRING_CHECK_IN_STUB = 1 << 0  // Omit string check in stub.
 };
 
 
+class StringAddStub: public StringStubBase {
+ public:
+  explicit StringAddStub(StringAddFlags flags) {
+    string_check_ = ((flags & NO_STRING_CHECK_IN_STUB) == 0);
+  }
+
+ private:
+  Major MajorKey() { return StringAdd; }
+  int MinorKey() { return string_check_ ? 0 : 1; }
+
+  void Generate(MacroAssembler* masm);
+
+  // Should the stub check whether arguments are strings?
+  bool string_check_;
+};
+
+
 class SubStringStub: public StringStubBase {
  public:
   SubStringStub() {}
 
  private:
   Major MajorKey() { return SubString; }
   int MinorKey() { return 0; }
 
   void Generate(MacroAssembler* masm);
 };
@@ skipping 18 matching lines @@
   Major MajorKey() { return StringCompare; }
   int MinorKey() { return 0; }
 
   void Generate(MacroAssembler* masm);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_CODEGEN_ARM_H_