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

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
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@@ skipping 579 matching lines @@
                          DwVfpRegister dst,
                          Register dst1,
                          Register dst2,
                          Register heap_number_map,
                          Register scratch1,
                          Register scratch2,
                          Label* not_number);
 };
 
 
+class StringDictionaryLookupStub: public CodeStub {
+ public:
+  enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
+
+  StringDictionaryLookupStub(LookupMode mode) : mode_(mode) { }
+
+  void Generate(MacroAssembler* masm);
+
+  static void GenerateNegativeLookup(MacroAssembler* masm,
+                                     Label* miss,
+                                     Label* done,
+                                     Register receiver,
+                                     Register properties,
+                                     String* name,
+                                     Register scratch0) ;
+
+  static void GeneratePositiveLookup(MacroAssembler* masm,
+                                     Label* miss,
+                                     Label* done,
+                                     Register elements,
+                                     Register name,
+                                     Register r0,
+                                     Register r1);
+ private:

[Mads Ager (chromium), 2011/05/05 11:54:56]

Could you leave line 623 blank and move this to line 624? :-)

[Vyacheslav Egorov (Chromium), 2011/05/05 12:30:16]

Done.

+
+  static const int kInlinedProbes = 4;
+  static const int kTotalProbes = 20;
+
+  static const int kCapacityOffset =
+      StringDictionary::kHeaderSize +
+      StringDictionary::kCapacityIndex * kPointerSize;
+
+  static const int kElementsStartOffset =
+      StringDictionary::kHeaderSize +
+      StringDictionary::kElementsStartIndex * kPointerSize;
+
+
+#ifdef DEBUG
+  void Print() {
+    PrintF("StringDictionaryLookupStub\n");
+  }
+#endif
+
+  Major MajorKey() { return StringDictionaryNegativeLookup; }
+
+  int MinorKey() {
+    return LookupModeBits::encode(mode_);
+  }
+
+  class LookupModeBits: public BitField<LookupMode, 0, 1> {};
+
+  LookupMode mode_;
+};
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_CODE_STUBS_ARM_H_