Partial ia32 implementation of optimized try/catch (by Kevin Millikin)

src/frames.h

 // Copyright 2012 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 68 matching lines @@
 
   static const int kInnerPointerToCodeCacheSize = 1024;
   InnerPointerToCodeCacheEntry cache_[kInnerPointerToCodeCacheSize];
 
   DISALLOW_COPY_AND_ASSIGN(InnerPointerToCodeCache);
 };
 
 
 class StackHandler BASE_EMBEDDED {
  public:
+  // Generated code in MacroAssembler::Throw relies on the bit patterns of
+  // the Kinds.  Low-order bit determines if the handler is for optimized
+  // code.
   enum Kind {
-    JS_ENTRY,
-    CATCH,
+    JS_ENTRY,   // Non-optimized.
+    CATCH = 2,  // Non-optimized,
+    OPTIMIZED_CATCH,
     FINALLY,
     LAST_KIND = FINALLY
   };
+  static const int kIsOptimizedMask = 1;
 
-  static const int kKindWidth = 2;
+  static const int kKindWidth = 3;
   STATIC_ASSERT(LAST_KIND < (1 << kKindWidth));
   static const int kIndexWidth = 32 - kKindWidth;
   class KindField: public BitField<StackHandler::Kind, 0, kKindWidth> {};
   class IndexField: public BitField<unsigned, kKindWidth, kIndexWidth> {};
 
   // Get the address of this stack handler.
   inline Address address() const;
 
   // Get the next stack handler in the chain.
   inline StackHandler* next() const;
 
+  inline Code* code() const;
+  inline int index() const;
+
   // Tells whether the given address is inside this handler.
   inline bool includes(Address address) const;
 
   // Garbage collection support.
   inline void Iterate(ObjectVisitor* v, Code* holder) const;
 
   // Conversion support.
   static inline StackHandler* FromAddress(Address address);
 
   // Testers
   inline bool is_js_entry() const;
   inline bool is_catch() const;
   inline bool is_finally() const;
+  inline bool is_optimized() const;
 
  private:
   // Accessors.
   inline Kind kind() const;
 
   inline Object** context_address() const;
   inline Object** code_address() const;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StackHandler);
 };
@@ skipping 762 matching lines @@
 };
 
 
 // Reads all frames on the current stack and copies them into the current
 // zone memory.
 Vector<StackFrame*> CreateStackMap(Zone* zone);
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_