1//===- llvm/ADT/DenseMapInfo.h - Type traits for DenseMap -------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines DenseMapInfo traits for DenseMap.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ADT_DENSEMAPINFO_H
15#define LLVM_ADT_DENSEMAPINFO_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/ADT/Hashing.h"
19#include "llvm/ADT/StringRef.h"
20#include "llvm/Support/PointerLikeTypeTraits.h"
21#include <cassert>
22#include <cstddef>
23#include <cstdint>
24#include <utility>
25
26namespace llvm {
27
28template<typename T>
29struct DenseMapInfo {
30 //static inline T getEmptyKey();
31 //static inline T getTombstoneKey();
32 //static unsigned getHashValue(const T &Val);
33 //static bool isEqual(const T &LHS, const T &RHS);
34};
35
36// Provide DenseMapInfo for all pointers.
37template<typename T>
38struct DenseMapInfo<T*> {
39 static inline T* getEmptyKey() {
40 uintptr_t Val = static_cast<uintptr_t>(-1);
41 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
42 return reinterpret_cast<T*>(Val);
43 }
44
45 static inline T* getTombstoneKey() {
46 uintptr_t Val = static_cast<uintptr_t>(-2);
47 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
48 return reinterpret_cast<T*>(Val);
49 }
50
51 static unsigned getHashValue(const T *PtrVal) {
52 return (unsigned((uintptr_t)PtrVal) >> 4) ^
53 (unsigned((uintptr_t)PtrVal) >> 9);
54 }
55
56 static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
57};
58
59// Provide DenseMapInfo for chars.
60template<> struct DenseMapInfo<char> {
61 static inline char getEmptyKey() { return ~0; }
62 static inline char getTombstoneKey() { return ~0 - 1; }
63 static unsigned getHashValue(const char& Val) { return Val * 37U; }
64
65 static bool isEqual(const char &LHS, const char &RHS) {
66 return LHS == RHS;
67 }
68};
69
70// Provide DenseMapInfo for unsigned shorts.
71template <> struct DenseMapInfo<unsigned short> {
72 static inline unsigned short getEmptyKey() { return 0xFFFF; }
73 static inline unsigned short getTombstoneKey() { return 0xFFFF - 1; }
74 static unsigned getHashValue(const unsigned short &Val) { return Val * 37U; }
75
76 static bool isEqual(const unsigned short &LHS, const unsigned short &RHS) {
77 return LHS == RHS;
78 }
79};
80
81// Provide DenseMapInfo for unsigned ints.
82template<> struct DenseMapInfo<unsigned> {
83 static inline unsigned getEmptyKey() { return ~0U; }
84 static inline unsigned getTombstoneKey() { return ~0U - 1; }
85 static unsigned getHashValue(const unsigned& Val) { return Val * 37U; }
86
87 static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
88 return LHS == RHS;
89 }
90};
91
92// Provide DenseMapInfo for unsigned longs.
93template<> struct DenseMapInfo<unsigned long> {
94 static inline unsigned long getEmptyKey() { return ~0UL; }
95 static inline unsigned long getTombstoneKey() { return ~0UL - 1L; }
96
97 static unsigned getHashValue(const unsigned long& Val) {
98 return (unsigned)(Val * 37UL);
99 }
100
101 static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
102 return LHS == RHS;
103 }
104};
105
106// Provide DenseMapInfo for unsigned long longs.
107template<> struct DenseMapInfo<unsigned long long> {
108 static inline unsigned long long getEmptyKey() { return ~0ULL; }
109 static inline unsigned long long getTombstoneKey() { return ~0ULL - 1ULL; }
110
111 static unsigned getHashValue(const unsigned long long& Val) {
112 return (unsigned)(Val * 37ULL);
113 }
114
115 static bool isEqual(const unsigned long long& LHS,
116 const unsigned long long& RHS) {
117 return LHS == RHS;
118 }
119};
120
121// Provide DenseMapInfo for shorts.
122template <> struct DenseMapInfo<short> {
123 static inline short getEmptyKey() { return 0x7FFF; }
124 static inline short getTombstoneKey() { return -0x7FFF - 1; }
125 static unsigned getHashValue(const short &Val) { return Val * 37U; }
126 static bool isEqual(const short &LHS, const short &RHS) { return LHS == RHS; }
127};
128
129// Provide DenseMapInfo for ints.
130template<> struct DenseMapInfo<int> {
131 static inline int getEmptyKey() { return 0x7fffffff; }
132 static inline int getTombstoneKey() { return -0x7fffffff - 1; }
133 static unsigned getHashValue(const int& Val) { return (unsigned)(Val * 37U); }
134
135 static bool isEqual(const int& LHS, const int& RHS) {
136 return LHS == RHS;
137 }
138};
139
140// Provide DenseMapInfo for longs.
141template<> struct DenseMapInfo<long> {
142 static inline long getEmptyKey() {
143 return (1UL << (sizeof(long) * 8 - 1)) - 1UL;
144 }
145
146 static inline long getTombstoneKey() { return getEmptyKey() - 1L; }
147
148 static unsigned getHashValue(const long& Val) {
149 return (unsigned)(Val * 37UL);
150 }
151
152 static bool isEqual(const long& LHS, const long& RHS) {
153 return LHS == RHS;
154 }
155};
156
157// Provide DenseMapInfo for long longs.
158template<> struct DenseMapInfo<long long> {
159 static inline long long getEmptyKey() { return 0x7fffffffffffffffLL; }
160 static inline long long getTombstoneKey() { return -0x7fffffffffffffffLL-1; }
161
162 static unsigned getHashValue(const long long& Val) {
163 return (unsigned)(Val * 37ULL);
164 }
165
166 static bool isEqual(const long long& LHS,
167 const long long& RHS) {
168 return LHS == RHS;
169 }
170};
171
172// Provide DenseMapInfo for all pairs whose members have info.
173template<typename T, typename U>
174struct DenseMapInfo<std::pair<T, U>> {
175 using Pair = std::pair<T, U>;
176 using FirstInfo = DenseMapInfo<T>;
177 using SecondInfo = DenseMapInfo<U>;
178
179 static inline Pair getEmptyKey() {
180 return std::make_pair(FirstInfo::getEmptyKey(),
181 SecondInfo::getEmptyKey());
182 }
183
184 static inline Pair getTombstoneKey() {
185 return std::make_pair(FirstInfo::getTombstoneKey(),
186 SecondInfo::getTombstoneKey());
187 }
188
189 static unsigned getHashValue(const Pair& PairVal) {
190 uint64_t key = (uint64_t)FirstInfo::getHashValue(PairVal.first) << 32
191 | (uint64_t)SecondInfo::getHashValue(PairVal.second);
192 key += ~(key << 32);
193 key ^= (key >> 22);
194 key += ~(key << 13);
195 key ^= (key >> 8);
196 key += (key << 3);
197 key ^= (key >> 15);
198 key += ~(key << 27);
199 key ^= (key >> 31);
200 return (unsigned)key;
201 }
202
203 static bool isEqual(const Pair &LHS, const Pair &RHS) {
204 return FirstInfo::isEqual(LHS.first, RHS.first) &&
205 SecondInfo::isEqual(LHS.second, RHS.second);
206 }
207};
208
209// Provide DenseMapInfo for StringRefs.
210template <> struct DenseMapInfo<StringRef> {
211 static inline StringRef getEmptyKey() {
212 return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)),
213 0);
214 }
215
216 static inline StringRef getTombstoneKey() {
217 return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
218 0);
219 }
220
221 static unsigned getHashValue(StringRef Val) {
222 assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
223 assert(Val.data() != getTombstoneKey().data() &&
224 "Cannot hash the tombstone key!");
225 return (unsigned)(hash_value(Val));
226 }
227
228 static bool isEqual(StringRef LHS, StringRef RHS) {
229 if (RHS.data() == getEmptyKey().data())
230 return LHS.data() == getEmptyKey().data();
231 if (RHS.data() == getTombstoneKey().data())
232 return LHS.data() == getTombstoneKey().data();
233 return LHS == RHS;
234 }
235};
236
237// Provide DenseMapInfo for ArrayRefs.
238template <typename T> struct DenseMapInfo<ArrayRef<T>> {
239 static inline ArrayRef<T> getEmptyKey() {
240 return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(0)),
241 size_t(0));
242 }
243
244 static inline ArrayRef<T> getTombstoneKey() {
245 return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(1)),
246 size_t(0));
247 }
248
249 static unsigned getHashValue(ArrayRef<T> Val) {
250 assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
251 assert(Val.data() != getTombstoneKey().data() &&
252 "Cannot hash the tombstone key!");
253 return (unsigned)(hash_value(Val));
254 }
255
256 static bool isEqual(ArrayRef<T> LHS, ArrayRef<T> RHS) {
257 if (RHS.data() == getEmptyKey().data())
258 return LHS.data() == getEmptyKey().data();
259 if (RHS.data() == getTombstoneKey().data())
260 return LHS.data() == getTombstoneKey().data();
261 return LHS == RHS;
262 }
263};
264
265template <> struct DenseMapInfo<hash_code> {
266 static inline hash_code getEmptyKey() { return hash_code(-1); }
267 static inline hash_code getTombstoneKey() { return hash_code(-2); }
268 static unsigned getHashValue(hash_code val) { return val; }
269 static bool isEqual(hash_code LHS, hash_code RHS) { return LHS == RHS; }
270};
271
272} // end namespace llvm
273
274#endif // LLVM_ADT_DENSEMAPINFO_H
275