Elements kind conversion in generated code (ia32).

src/code-stubs.h

 // Copyright 2011 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 51 matching lines @@
   V(ToNumber)                            \
   V(CounterOp)                           \
   V(ArgumentsAccess)                     \
   V(RegExpConstructResult)               \
   V(NumberToString)                      \
   V(CEntry)                              \
   V(JSEntry)                             \
   V(KeyedLoadElement)                    \
   V(KeyedStoreElement)                   \
   V(DebuggerStatement)                   \
-  V(StringDictionaryLookup)
+  V(StringDictionaryLookup)              \
+  V(FastElementsConversion)
 
 // List of code stubs only used on ARM platforms.
 #ifdef V8_TARGET_ARCH_ARM
 #define CODE_STUB_LIST_ARM(V)  \
   V(GetProperty)               \
   V(SetProperty)               \
   V(InvokeBuiltin)             \
   V(RegExpCEntry)              \
   V(DirectCEntry)
 #else
@@ skipping 935 matching lines @@
   void CheckOddball(MacroAssembler* masm,
                     Type type,
                     Heap::RootListIndex value,
                     bool result);
   void GenerateTypeTransition(MacroAssembler* masm);
 
   Register tos_;
   Types types_;
 };
 
+
+class FastElementsConversionStub : public CodeStub {
+ public:
+  FastElementsConversionStub(ElementsKind from,
+                             ElementsKind to,
+                             bool is_jsarray,
+                             StrictModeFlag strict_mode)
+      : from_(from),
+        to_(to),
+        is_jsarray_(is_jsarray),
+        strict_mode_(strict_mode) {}
+
+ private:

[Jakob Kummerow, 2011/10/13 09:15:59]

nit: classes, then methods, then data members. (see
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Declar...)

[Yang, 2011/10/13 09:58:53]

Done.

+  ElementsKind from_;
+  ElementsKind to_;
+  bool is_jsarray_;
+  StrictModeFlag strict_mode_;
+
+  class FromBits:       public BitField<ElementsKind,    0, 8> {};
+  class ToBits:         public BitField<ElementsKind,    8, 8> {};
+  class IsJSArrayBits:  public BitField<bool,           16, 8> {};
+  class StrictModeBits: public BitField<StrictModeFlag, 24, 8> {};
+
+  Major MajorKey() { return FastElementsConversion; }
+  int MinorKey() {
+    return FromBits::encode(from_) |
+        ToBits::encode(to_) |
+        IsJSArrayBits::encode(is_jsarray_) |
+        StrictModeBits::encode(strict_mode_);
+  }
+
+  void Generate(MacroAssembler* masm);
+  static void GenerateSmiOnlyToObject(MacroAssembler* masm);
+  static void GenerateSmiOnlyToDouble(MacroAssembler* masm,
+                                      StrictModeFlag strict_mode);
+  static void GenerateDoubleToObject(MacroAssembler* masm,
+                                     StrictModeFlag strict_mode);
+
+  DISALLOW_COPY_AND_ASSIGN(FastElementsConversionStub);
+};
+
 } }  // namespace v8::internal
 
 #endif  // V8_CODE_STUBS_H_