1// Copyright 2014 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#ifndef V8_COMPILER_NODE_CACHE_H_
6#define V8_COMPILER_NODE_CACHE_H_
7
8#include "src/base/functional.h"
9#include "src/base/macros.h"
10
11namespace v8 {
12namespace internal {
13
14// Forward declarations.
15class Zone;
16template <typename>
17class ZoneVector;
18
19
20namespace compiler {
21
22// Forward declarations.
23class Node;
24
25
26// A cache for nodes based on a key. Useful for implementing canonicalization of
27// nodes such as constants, parameters, etc.
28template <typename Key, typename Hash = base::hash<Key>,
29          typename Pred = std::equal_to<Key> >
30class NodeCache final {
31 public:
32  explicit NodeCache(unsigned max = 256)
33      : entries_(nullptr), size_(0), max_(max) {}
34  ~NodeCache() {}
35
36  // Search for node associated with {key} and return a pointer to a memory
37  // location in this cache that stores an entry for the key. If the location
38  // returned by this method contains a non-nullptr node, the caller can use
39  // that
40  // node. Otherwise it is the responsibility of the caller to fill the entry
41  // with a new node.
42  // Note that a previous cache entry may be overwritten if the cache becomes
43  // too full or encounters too many hash collisions.
44  Node** Find(Zone* zone, Key key);
45
46  // Appends all nodes from this cache to {nodes}.
47  void GetCachedNodes(ZoneVector<Node*>* nodes);
48
49 private:
50  struct Entry;
51
52  Entry* entries_;  // lazily-allocated hash entries.
53  size_t size_;
54  size_t max_;
55  Hash hash_;
56  Pred pred_;
57
58  bool Resize(Zone* zone);
59
60  DISALLOW_COPY_AND_ASSIGN(NodeCache);
61};
62
63// Various default cache types.
64typedef NodeCache<int32_t> Int32NodeCache;
65typedef NodeCache<int64_t> Int64NodeCache;
66
67// All we want is the numeric value of the RelocInfo::Mode enum. We typedef
68// below to avoid pulling in assembler.h
69typedef char RelocInfoMode;
70typedef std::pair<int32_t, RelocInfoMode> RelocInt32Key;
71typedef std::pair<int64_t, RelocInfoMode> RelocInt64Key;
72typedef NodeCache<RelocInt32Key> RelocInt32NodeCache;
73typedef NodeCache<RelocInt64Key> RelocInt64NodeCache;
74#if V8_HOST_ARCH_32_BIT
75typedef Int32NodeCache IntPtrNodeCache;
76#else
77typedef Int64NodeCache IntPtrNodeCache;
78#endif
79
80}  // namespace compiler
81}  // namespace internal
82}  // namespace v8
83
84#endif  // V8_COMPILER_NODE_CACHE_H_
85