diff options
Diffstat (limited to 'deps/v8/src/ast/context-slot-cache.cc')
-rw-r--r-- | deps/v8/src/ast/context-slot-cache.cc | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/deps/v8/src/ast/context-slot-cache.cc b/deps/v8/src/ast/context-slot-cache.cc new file mode 100644 index 0000000000..43bd6d6b19 --- /dev/null +++ b/deps/v8/src/ast/context-slot-cache.cc @@ -0,0 +1,91 @@ +// Copyright 2016 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/ast/context-slot-cache.h" + +#include <stdlib.h> + +#include "src/ast/scopes.h" +#include "src/bootstrapper.h" + +namespace v8 { +namespace internal { + +int ContextSlotCache::Hash(Object* data, String* name) { + // Uses only lower 32 bits if pointers are larger. + uintptr_t addr_hash = + static_cast<uint32_t>(reinterpret_cast<uintptr_t>(data)) >> 2; + return static_cast<int>((addr_hash ^ name->Hash()) % kLength); +} + +int ContextSlotCache::Lookup(Object* data, String* name, VariableMode* mode, + InitializationFlag* init_flag, + MaybeAssignedFlag* maybe_assigned_flag) { + int index = Hash(data, name); + Key& key = keys_[index]; + if ((key.data == data) && key.name->Equals(name)) { + Value result(values_[index]); + if (mode != nullptr) *mode = result.mode(); + if (init_flag != nullptr) *init_flag = result.initialization_flag(); + if (maybe_assigned_flag != nullptr) + *maybe_assigned_flag = result.maybe_assigned_flag(); + return result.index() + kNotFound; + } + return kNotFound; +} + +void ContextSlotCache::Update(Handle<Object> data, Handle<String> name, + VariableMode mode, InitializationFlag init_flag, + MaybeAssignedFlag maybe_assigned_flag, + int slot_index) { + DisallowHeapAllocation no_gc; + Handle<String> internalized_name; + DCHECK(slot_index > kNotFound); + if (StringTable::InternalizeStringIfExists(name->GetIsolate(), name) + .ToHandle(&internalized_name)) { + int index = Hash(*data, *internalized_name); + Key& key = keys_[index]; + key.data = *data; + key.name = *internalized_name; + // Please note value only takes a uint as index. + values_[index] = + Value(mode, init_flag, maybe_assigned_flag, slot_index - kNotFound) + .raw(); +#ifdef DEBUG + ValidateEntry(data, name, mode, init_flag, maybe_assigned_flag, slot_index); +#endif + } +} + +void ContextSlotCache::Clear() { + for (int index = 0; index < kLength; index++) keys_[index].data = nullptr; +} + +#ifdef DEBUG + +void ContextSlotCache::ValidateEntry(Handle<Object> data, Handle<String> name, + VariableMode mode, + InitializationFlag init_flag, + MaybeAssignedFlag maybe_assigned_flag, + int slot_index) { + DisallowHeapAllocation no_gc; + Handle<String> internalized_name; + if (StringTable::InternalizeStringIfExists(name->GetIsolate(), name) + .ToHandle(&internalized_name)) { + int index = Hash(*data, *name); + Key& key = keys_[index]; + DCHECK(key.data == *data); + DCHECK(key.name->Equals(*name)); + Value result(values_[index]); + DCHECK(result.mode() == mode); + DCHECK(result.initialization_flag() == init_flag); + DCHECK(result.maybe_assigned_flag() == maybe_assigned_flag); + DCHECK(result.index() + kNotFound == slot_index); + } +} + +#endif // DEBUG + +} // namespace internal +} // namespace v8 |