1 // Copyright 2016 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "src/lookup-cache.h" 6 7 #include "src/objects-inl.h" 8 9 namespace v8 { 10 namespace internal { 11 12 // static 13 int DescriptorLookupCache::Hash(Object* source, Name* name) { 14 DCHECK(name->IsUniqueName()); 15 // Uses only lower 32 bits if pointers are larger. 16 uint32_t source_hash = 17 static_cast<uint32_t>(reinterpret_cast<uintptr_t>(source)) >> 18 kPointerSizeLog2; 19 uint32_t name_hash = name->hash_field(); 20 return (source_hash ^ name_hash) % kLength; 21 } 22 23 int DescriptorLookupCache::Lookup(Map* source, Name* name) { 24 int index = Hash(source, name); 25 Key& key = keys_[index]; 26 if ((key.source == source) && (key.name == name)) return results_[index]; 27 return kAbsent; 28 } 29 30 void DescriptorLookupCache::Update(Map* source, Name* name, int result) { 31 DCHECK(result != kAbsent); 32 int index = Hash(source, name); 33 Key& key = keys_[index]; 34 key.source = source; 35 key.name = name; 36 results_[index] = result; 37 } 38 39 } // namespace internal 40 } // namespace v8 41
