Use a dictionary-mode code cache on the map rather than a dual system.

src/ic/stub-cache.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/ic/stub-cache.h"
 
 #include "src/base/bits.h"
 #include "src/type-info.h"
 
 namespace v8 {
 namespace internal {
 
 
 StubCache::StubCache(Isolate* isolate) : isolate_(isolate) {}
 
 
 void StubCache::Initialize() {
   DCHECK(base::bits::IsPowerOfTwo32(kPrimaryTableSize));
   DCHECK(base::bits::IsPowerOfTwo32(kSecondaryTableSize));
   Clear();
 }
 
 
 static Code::Flags CommonStubCacheChecks(Name* name, Map* map,
                                          Code::Flags flags) {
-  flags = Code::RemoveTypeAndHolderFromFlags(flags);
+  flags = Code::RemoveHolderFromFlags(flags);
 
   // Validate that the name does not move on scavenge, and that we
   // can use identity checks instead of structural equality checks.
   DCHECK(!name->GetHeap()->InNewSpace(name));
   DCHECK(name->IsUniqueName());
 
   // The state bits are not important to the hash function because the stub
   // cache only contains handlers. Make sure that the bits are the least
   // significant so they will be the ones masked out.
   DCHECK_EQ(Code::HANDLER, Code::ExtractKindFromFlags(flags));
   STATIC_ASSERT((Code::ICStateField::kMask & 1) == 1);
 
-  // Make sure that the code type and cache holder are not included in the hash.
-  DCHECK(Code::ExtractTypeFromFlags(flags) == 0);
+  // Make sure that the cache holder are not included in the hash.
   DCHECK(Code::ExtractCacheHolderFromFlags(flags) == 0);
 
   return flags;
 }
 
 
 Code* StubCache::Set(Name* name, Map* map, Code* code) {
   Code::Flags flags = CommonStubCacheChecks(name, map, code->flags());
 
   // Compute the primary entry.
   int primary_offset = PrimaryOffset(name, flags, map);
   Entry* primary = entry(primary_, primary_offset);
   Code* old_code = primary->value;
 
   // If the primary entry has useful data in it, we retire it to the
   // secondary cache before overwriting it.
   if (old_code != isolate_->builtins()->builtin(Builtins::kIllegal)) {
     Map* old_map = primary->map;
-    Code::Flags old_flags =
-        Code::RemoveTypeAndHolderFromFlags(old_code->flags());
+    Code::Flags old_flags = Code::RemoveHolderFromFlags(old_code->flags());
     int seed = PrimaryOffset(primary->key, old_flags, old_map);
     int secondary_offset = SecondaryOffset(primary->key, old_flags, seed);
     Entry* secondary = entry(secondary_, secondary_offset);
     *secondary = *primary;
   }
 
   // Update primary cache.
   primary->key = name;
   primary->value = code;
   primary->map = map;
@@ skipping 66 matching lines @@
       int offset = SecondaryOffset(*name, flags, primary_offset);
       if (entry(secondary_, offset) == &secondary_[i] &&
           TypeFeedbackOracle::IsRelevantFeedback(map, *native_context)) {
         types->AddMapIfMissing(Handle<Map>(map), zone);
       }
     }
   }
 }
 }  // namespace internal
 }  // namespace v8