| // Copyright 2014 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/compiler/node-cache.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| #define INITIAL_SIZE 16 |
| #define LINEAR_PROBE 5 |
| |
| template <typename Key> |
| int32_t NodeCacheHash(Key key) { |
| UNIMPLEMENTED(); |
| return 0; |
| } |
| |
| template <> |
| inline int32_t NodeCacheHash(int32_t key) { |
| return ComputeIntegerHash(key, 0); |
| } |
| |
| |
| template <> |
| inline int32_t NodeCacheHash(int64_t key) { |
| return ComputeLongHash(key); |
| } |
| |
| |
| template <> |
| inline int32_t NodeCacheHash(double key) { |
| return ComputeLongHash(bit_cast<int64_t>(key)); |
| } |
| |
| |
| template <> |
| inline int32_t NodeCacheHash(void* key) { |
| return ComputePointerHash(key); |
| } |
| |
| |
| template <typename Key> |
| bool NodeCache<Key>::Resize(Zone* zone) { |
| if (size_ >= max_) return false; // Don't grow past the maximum size. |
| |
| // Allocate a new block of entries 4x the size. |
| Entry* old_entries = entries_; |
| int old_size = size_ + LINEAR_PROBE; |
| size_ = size_ * 4; |
| int num_entries = size_ + LINEAR_PROBE; |
| entries_ = zone->NewArray<Entry>(num_entries); |
| memset(entries_, 0, sizeof(Entry) * num_entries); |
| |
| // Insert the old entries into the new block. |
| for (int i = 0; i < old_size; i++) { |
| Entry* old = &old_entries[i]; |
| if (old->value_ != NULL) { |
| int hash = NodeCacheHash(old->key_); |
| int start = hash & (size_ - 1); |
| int end = start + LINEAR_PROBE; |
| for (int j = start; j < end; j++) { |
| Entry* entry = &entries_[j]; |
| if (entry->value_ == NULL) { |
| entry->key_ = old->key_; |
| entry->value_ = old->value_; |
| break; |
| } |
| } |
| } |
| } |
| return true; |
| } |
| |
| |
| template <typename Key> |
| Node** NodeCache<Key>::Find(Zone* zone, Key key) { |
| int32_t hash = NodeCacheHash(key); |
| if (entries_ == NULL) { |
| // Allocate the initial entries and insert the first entry. |
| int num_entries = INITIAL_SIZE + LINEAR_PROBE; |
| entries_ = zone->NewArray<Entry>(num_entries); |
| size_ = INITIAL_SIZE; |
| memset(entries_, 0, sizeof(Entry) * num_entries); |
| Entry* entry = &entries_[hash & (INITIAL_SIZE - 1)]; |
| entry->key_ = key; |
| return &entry->value_; |
| } |
| |
| while (true) { |
| // Search up to N entries after (linear probing). |
| int start = hash & (size_ - 1); |
| int end = start + LINEAR_PROBE; |
| for (int i = start; i < end; i++) { |
| Entry* entry = &entries_[i]; |
| if (entry->key_ == key) return &entry->value_; |
| if (entry->value_ == NULL) { |
| entry->key_ = key; |
| return &entry->value_; |
| } |
| } |
| |
| if (!Resize(zone)) break; // Don't grow past the maximum size. |
| } |
| |
| // If resized to maximum and still didn't find space, overwrite an entry. |
| Entry* entry = &entries_[hash & (size_ - 1)]; |
| entry->key_ = key; |
| entry->value_ = NULL; |
| return &entry->value_; |
| } |
| |
| |
| template class NodeCache<int64_t>; |
| template class NodeCache<int32_t>; |
| template class NodeCache<void*>; |
| } |
| } |
| } // namespace v8::internal::compiler |