Unroll more StringDictionary lookup probes both for positive and negative dictionary lookups.

src/ia32/code-stubs-ia32.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 406 matching lines @@
 
   const char* GetName() { return "NumberToStringStub"; }
 
 #ifdef DEBUG
   void Print() {
     PrintF("NumberToStringStub\n");
   }
 #endif
 };
 
+
+
+class StringDictionaryLookupStub: public CodeStub {
+ public:
+  enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
+
+  StringDictionaryLookupStub(Register dictionary,
+                             Register result,
+                             Register index,
+                             LookupMode mode)
+      : dictionary_(dictionary), result_(result), index_(index), mode_(mode) { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("StringDictionaryLookupStub\n");
+  }
+#endif
+
+  Major MajorKey() { return StringDictionaryNegativeLookup; }
+
+  int MinorKey() {
+    return DictionaryBits::encode(dictionary_.code()) |
+        ResultBits::encode(result_.code()) |
+        IndexBits::encode(index_.code()) |
+        LookupModeBits::encode(mode_);
+  }
+
+  class DictionaryBits: public BitField<int, 0, 3> {};
+  class ResultBits: public BitField<int, 3, 3> {};
+  class IndexBits: public BitField<int, 6, 3> {};
+  class LookupModeBits: public BitField<LookupMode, 9, 1> {};
+
+  Register dictionary_;
+  Register result_;
+  Register index_;
+  LookupMode mode_;
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_CODE_STUBS_IA32_H_