Extract common code in string compare loops.

src/arm/code-stubs-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 328 matching lines @@
   // Compares two flat ASCII strings for equality and returns result
   // in r0.
   static void GenerateFlatAsciiStringEquals(MacroAssembler* masm,
                                             Register left,
                                             Register right,
                                             Register scratch1,
                                             Register scratch2,
                                             Register scratch3);
 
  private:
-  Major MajorKey() { return StringCompare; }
-  int MinorKey() { return 0; }
+  virtual Major MajorKey() { return StringCompare; }
+  virtual int MinorKey() { return 0; }
+  virtual void Generate(MacroAssembler* masm);
 
-  void Generate(MacroAssembler* masm);
+  static void GenerateAsciiCharsCompareLoop(MacroAssembler* masm,
+                                            Register left,
+                                            Register right,
+                                            Register length,
+                                            Register scratch1,
+                                            Register scratch2,
+                                            Label* chars_not_equal);
 };
 
 
 // This stub can convert a signed int32 to a heap number (double).  It does
 // not work for int32s that are in Smi range!  No GC occurs during this stub
 // so you don't have to set up the frame.
 class WriteInt32ToHeapNumberStub : public CodeStub {
  public:
   WriteInt32ToHeapNumberStub(Register the_int,
                              Register the_heap_number,
@@ skipping 238 matching lines @@
                          Register heap_number_map,
                          Register scratch1,
                          Register scratch2,
                          Label* not_number);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_CODE_STUBS_ARM_H_