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Diffstat (limited to 'deps/v8/src/compiler/node-cache.cc')
-rw-r--r-- | deps/v8/src/compiler/node-cache.cc | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/deps/v8/src/compiler/node-cache.cc b/deps/v8/src/compiler/node-cache.cc new file mode 100644 index 000000000..c3ee58c5a --- /dev/null +++ b/deps/v8/src/compiler/node-cache.cc @@ -0,0 +1,120 @@ +// 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(BitCast<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 |