Reorder switch clauses using newly-introduced execution counters in

src/type-info.cc

 // 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 45 matching lines @@
     info = TypeInfo::Unknown();
   }
   return info;
 }
 
 
 TypeFeedbackOracle::TypeFeedbackOracle(Handle<Code> code,
                                        Handle<Context> native_context,
                                        Isolate* isolate,
                                        Zone* zone)
-    : native_context_(native_context),
+    : code_(code),
+      native_context_(native_context),
       isolate_(isolate),
       zone_(zone) {
   BuildDictionary(code);
   ASSERT(dictionary_->IsDictionary());
 }
 
 
 static uint32_t IdToKey(TypeFeedbackId ast_id) {
   return static_cast<uint32_t>(ast_id.ToInt());
 }
@@ skipping 406 matching lines @@
   TypeInfo unknown = TypeInfo::Unknown();
   if (!object->IsCode()) return unknown;
   Handle<Code> code = Handle<Code>::cast(object);
   if (!code->is_compare_ic_stub()) return unknown;
 
   CompareIC::State state = ICCompareStub::CompareState(code->stub_info());
   return TypeFromCompareType(state);
 }
 
 
+int TypeFeedbackOracle::SwitchHitCount(CaseClause* clause) {
+  Handle<Object> object = GetInfo(clause->CounterId());
+  if (!object->IsSmi()) return 0;
+
+  int ret = Smi::cast(*object)->value();
+  if (ret == 0) return ret;
+
+  // Reset counter after observing it
+  // XXX: O(n) for each hit counter
+  Object* raw_info = code_->type_feedback_info();
+  if (raw_info->IsTypeFeedbackInfo()) {
+    Handle<TypeFeedbackCells> cache(
+        TypeFeedbackInfo::cast(raw_info)->type_feedback_cells());
+    for (int i = 0; i < cache->CellCount(); i++) {
+      TypeFeedbackId ast_id = cache->AstId(i);
+      if (ast_id.ToInt() != clause->CounterId().ToInt()) continue;
+
+      *reinterpret_cast<Smi**>(cache->Cell(i)->ValueAddress()) =
+          Smi::FromInt(0);
+    }
+  }
+
+  return ret;
+}
+
+
 TypeInfo TypeFeedbackOracle::IncrementType(CountOperation* expr) {
   Handle<Object> object = GetInfo(expr->CountBinOpFeedbackId());
   TypeInfo unknown = TypeInfo::Unknown();
   if (!object->IsCode()) return unknown;
   Handle<Code> code = Handle<Code>::cast(object);
   if (!code->is_binary_op_stub()) return unknown;
 
   BinaryOpIC::TypeInfo left_type, right_type, unused_result_type;
   BinaryOpStub::decode_types_from_minor_key(code->stub_info(), &left_type,
                                             &right_type, &unused_result_type);
@@ skipping 255 matching lines @@
   USE(maybe_result);
 #ifdef DEBUG
   Object* result = NULL;
   // Dictionary has been allocated with sufficient size for all elements.
   ASSERT(maybe_result->ToObject(&result));
   ASSERT(*dictionary_ == result);
 #endif
 }
 
 } }  // namespace v8::internal