Stop overallocating feedback vector slots.

src/type-info.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/ast.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/ic/ic.h"
@@ skipping 88 matching lines @@
   }
 
   // If we can't find an IC, assume we've seen *something*, but we don't know
   // what. PREMONOMORPHIC roughly encodes this meaning.
   return PREMONOMORPHIC;
 }
 
 
 InlineCacheState TypeFeedbackOracle::LoadInlineCacheState(
     FeedbackVectorICSlot slot) {
-  Code::Kind kind = feedback_vector_->GetKind(slot);
-  if (kind == Code::LOAD_IC) {
-    LoadICNexus nexus(feedback_vector_, slot);
-    return nexus.StateFromFeedback();
-  } else if (kind == Code::KEYED_LOAD_IC) {
-    KeyedLoadICNexus nexus(feedback_vector_, slot);
-    return nexus.StateFromFeedback();
+  if (!slot.IsInvalid()) {
+    Code::Kind kind = feedback_vector_->GetKind(slot);
+    if (kind == Code::LOAD_IC) {
+      LoadICNexus nexus(feedback_vector_, slot);
+      return nexus.StateFromFeedback();
+    } else if (kind == Code::KEYED_LOAD_IC) {
+      KeyedLoadICNexus nexus(feedback_vector_, slot);
+      return nexus.StateFromFeedback();
+    }
   }
 
   // If we can't find an IC, assume we've seen *something*, but we don't know
   // what. PREMONOMORPHIC roughly encodes this meaning.
   return PREMONOMORPHIC;
 }
 
 
 bool TypeFeedbackOracle::StoreIsUninitialized(TypeFeedbackId ast_id) {
   Handle<Object> maybe_code = GetInfo(ast_id);
@@ skipping 198 matching lines @@
     all_strings &= receiver_types->at(i)->IsStringMap();
   }
   return all_strings;
 }
 
 
 void TypeFeedbackOracle::PropertyReceiverTypes(FeedbackVectorICSlot slot,
                                                Handle<Name> name,
                                                SmallMapList* receiver_types) {
   receiver_types->Clear();
-  LoadICNexus nexus(feedback_vector_, slot);
-  Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
-  CollectReceiverTypes(&nexus, name, flags, receiver_types);
+  if (!slot.IsInvalid()) {
+    LoadICNexus nexus(feedback_vector_, slot);
+    Code::Flags flags = Code::ComputeHandlerFlags(Code::LOAD_IC);
+    CollectReceiverTypes(&nexus, name, flags, receiver_types);
+  }
 }
 
 
 void TypeFeedbackOracle::KeyedPropertyReceiverTypes(
     FeedbackVectorICSlot slot, SmallMapList* receiver_types, bool* is_string,
     IcCheckType* key_type) {
   receiver_types->Clear();
-  KeyedLoadICNexus nexus(feedback_vector_, slot);
-  CollectReceiverTypes<FeedbackNexus>(&nexus, receiver_types);
-  *is_string = HasOnlyStringMaps(receiver_types);
-  *key_type = nexus.FindFirstName() != NULL ? PROPERTY : ELEMENT;
+  if (slot.IsInvalid()) {
+    *is_string = false;
+    *key_type = ELEMENT;
+  } else {
+    KeyedLoadICNexus nexus(feedback_vector_, slot);
+    CollectReceiverTypes<FeedbackNexus>(&nexus, receiver_types);
+    *is_string = HasOnlyStringMaps(receiver_types);
+    *key_type = nexus.FindFirstName() != NULL ? PROPERTY : ELEMENT;
+  }
 }
 
 
 void TypeFeedbackOracle::AssignmentReceiverTypes(TypeFeedbackId id,
                                                  Handle<Name> name,
                                                  SmallMapList* receiver_types) {
   receiver_types->Clear();
   Code::Flags flags = Code::ComputeHandlerFlags(Code::STORE_IC);
   CollectReceiverTypes(id, name, flags, receiver_types);
 }
@@ skipping 157 matching lines @@
   // Dictionary has been allocated with sufficient size for all elements.
   DisallowHeapAllocation no_need_to_resize_dictionary;
   HandleScope scope(isolate());
   USE(UnseededNumberDictionary::AtNumberPut(
       dictionary_, IdToKey(ast_id), handle(target, isolate())));
 }
 
 
 }  // namespace internal
 }  // namespace v8