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

src/frames.h

Index: src/frames.h
diff --git a/src/frames.h b/src/frames.h
index 30f7e1f00e552575295b074b08d5bb4396461cbb..76d4991a020d45dc3c380b55542b37ea068f76de 100644
--- a/src/frames.h
+++ b/src/frames.h
@@ -86,14 +86,19 @@ class 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> {};
@@ -105,6 +110,9 @@ class StackHandler BASE_EMBEDDED {
   // 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;
 
@@ -118,6 +126,7 @@ class StackHandler BASE_EMBEDDED {
   inline bool is_js_entry() const;
   inline bool is_catch() const;
   inline bool is_finally() const;
+  inline bool is_optimized() const;
 
  private:
   // Accessors.