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/v8.h"
9 
10 #include "src/compiler/node.h"
11 
12 namespace v8 {
13 namespace internal {
14 namespace compiler {
15 
16 // A cache for nodes based on a key. Useful for implementing canonicalization of
17 // nodes such as constants, parameters, etc.
18 template <typename Key>
19 class NodeCache {
20  public:
entries_(NULL)21   explicit NodeCache(int max = 256) : entries_(NULL), size_(0), max_(max) {}
22 
23   // Search for node associated with {key} and return a pointer to a memory
24   // location in this cache that stores an entry for the key. If the location
25   // returned by this method contains a non-NULL node, the caller can use that
26   // node. Otherwise it is the responsibility of the caller to fill the entry
27   // with a new node.
28   // Note that a previous cache entry may be overwritten if the cache becomes
29   // too full or encounters too many hash collisions.
30   Node** Find(Zone* zone, Key key);
31 
32  private:
33   struct Entry {
34     Key key_;
35     Node* value_;
36   };
37 
38   Entry* entries_;  // lazily-allocated hash entries.
39   int32_t size_;
40   int32_t max_;
41 
42   bool Resize(Zone* zone);
43 };
44 
45 // Various default cache types.
46 typedef NodeCache<int64_t> Int64NodeCache;
47 typedef NodeCache<int32_t> Int32NodeCache;
48 typedef NodeCache<void*> PtrNodeCache;
49 }
50 }
51 }  // namespace v8::internal::compiler
52 
53 #endif  // V8_COMPILER_NODE_CACHE_H_
54