1//===- llvm/ADT/DenseMapInfo.h - Type traits for DenseMap -------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines DenseMapInfo traits for DenseMap.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_ADT_DENSEMAPINFO_H
14#define LLVM_ADT_DENSEMAPINFO_H
15
16#include "llvm/ADT/ArrayRef.h"
17#include "llvm/ADT/Hashing.h"
18#include "llvm/ADT/StringRef.h"
19#include "llvm/Support/PointerLikeTypeTraits.h"
20#include <cassert>
21#include <cstddef>
22#include <cstdint>
23#include <utility>
24
25namespace llvm {
26
27template<typename T>
28struct DenseMapInfo {
29 //static inline T getEmptyKey();
30 //static inline T getTombstoneKey();
31 //static unsigned getHashValue(const T &Val);
32 //static bool isEqual(const T &LHS, const T &RHS);
33};
34
35// Provide DenseMapInfo for all pointers.
36template<typename T>
37struct DenseMapInfo<T*> {
38 static inline T* getEmptyKey() {
39 uintptr_t Val = static_cast<uintptr_t>(-1);
40 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
41 return reinterpret_cast<T*>(Val);
42 }
43
44 static inline T* getTombstoneKey() {
45 uintptr_t Val = static_cast<uintptr_t>(-2);
46 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
47 return reinterpret_cast<T*>(Val);
48 }
49
50 static unsigned getHashValue(const T *PtrVal) {
51 return (unsigned((uintptr_t)PtrVal) >> 4) ^
52 (unsigned((uintptr_t)PtrVal) >> 9);
53 }
54
55 static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
56};
57
58// Provide DenseMapInfo for chars.
59template<> struct DenseMapInfo<char> {
60 static inline char getEmptyKey() { return ~0; }
61 static inline char getTombstoneKey() { return ~0 - 1; }
62 static unsigned getHashValue(const char& Val) { return Val * 37U; }
63
64 static bool isEqual(const char &LHS, const char &RHS) {
65 return LHS == RHS;
66 }
67};
68
69// Provide DenseMapInfo for unsigned shorts.
70template <> struct DenseMapInfo<unsigned short> {
71 static inline unsigned short getEmptyKey() { return 0xFFFF; }
72 static inline unsigned short getTombstoneKey() { return 0xFFFF - 1; }
73 static unsigned getHashValue(const unsigned short &Val) { return Val * 37U; }
74
75 static bool isEqual(const unsigned short &LHS, const unsigned short &RHS) {
76 return LHS == RHS;
77 }
78};
79
80// Provide DenseMapInfo for unsigned ints.
81template<> struct DenseMapInfo<unsigned> {
82 static inline unsigned getEmptyKey() { return ~0U; }
83 static inline unsigned getTombstoneKey() { return ~0U - 1; }
84 static unsigned getHashValue(const unsigned& Val) { return Val * 37U; }
85
86 static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
87 return LHS == RHS;
88 }
89};
90
91// Provide DenseMapInfo for unsigned longs.
92template<> struct DenseMapInfo<unsigned long> {
93 static inline unsigned long getEmptyKey() { return ~0UL; }
94 static inline unsigned long getTombstoneKey() { return ~0UL - 1L; }
95
96 static unsigned getHashValue(const unsigned long& Val) {
97 return (unsigned)(Val * 37UL);
98 }
99
100 static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
101 return LHS == RHS;
102 }
103};
104
105// Provide DenseMapInfo for unsigned long longs.
106template<> struct DenseMapInfo<unsigned long long> {
107 static inline unsigned long long getEmptyKey() { return ~0ULL; }
108 static inline unsigned long long getTombstoneKey() { return ~0ULL - 1ULL; }
109
110 static unsigned getHashValue(const unsigned long long& Val) {
111 return (unsigned)(Val * 37ULL);
112 }
113
114 static bool isEqual(const unsigned long long& LHS,
115 const unsigned long long& RHS) {
116 return LHS == RHS;
117 }
118};
119
120// Provide DenseMapInfo for shorts.
121template <> struct DenseMapInfo<short> {
122 static inline short getEmptyKey() { return 0x7FFF; }
123 static inline short getTombstoneKey() { return -0x7FFF - 1; }
124 static unsigned getHashValue(const short &Val) { return Val * 37U; }
125 static bool isEqual(const short &LHS, const short &RHS) { return LHS == RHS; }
126};
127
128// Provide DenseMapInfo for ints.
129template<> struct DenseMapInfo<int> {
130 static inline int getEmptyKey() { return 0x7fffffff; }
131 static inline int getTombstoneKey() { return -0x7fffffff - 1; }
132 static unsigned getHashValue(const int& Val) { return (unsigned)(Val * 37U); }
133
134 static bool isEqual(const int& LHS, const int& RHS) {
135 return LHS == RHS;
136 }
137};
138
139// Provide DenseMapInfo for longs.
140template<> struct DenseMapInfo<long> {
141 static inline long getEmptyKey() {
142 return (1UL << (sizeof(long) * 8 - 1)) - 1UL;
143 }
144
145 static inline long getTombstoneKey() { return getEmptyKey() - 1L; }
146
147 static unsigned getHashValue(const long& Val) {
148 return (unsigned)(Val * 37UL);
149 }
150
151 static bool isEqual(const long& LHS, const long& RHS) {
152 return LHS == RHS;
153 }
154};
155
156// Provide DenseMapInfo for long longs.
157template<> struct DenseMapInfo<long long> {
158 static inline long long getEmptyKey() { return 0x7fffffffffffffffLL; }
159 static inline long long getTombstoneKey() { return -0x7fffffffffffffffLL-1; }
160
161 static unsigned getHashValue(const long long& Val) {
162 return (unsigned)(Val * 37ULL);
163 }
164
165 static bool isEqual(const long long& LHS,
166 const long long& RHS) {
167 return LHS == RHS;
168 }
169};
170
171// Provide DenseMapInfo for all pairs whose members have info.
172template<typename T, typename U>
173struct DenseMapInfo<std::pair<T, U>> {
174 using Pair = std::pair<T, U>;
175 using FirstInfo = DenseMapInfo<T>;
176 using SecondInfo = DenseMapInfo<U>;
177
178 static inline Pair getEmptyKey() {
179 return std::make_pair(FirstInfo::getEmptyKey(),
180 SecondInfo::getEmptyKey());
181 }
182
183 static inline Pair getTombstoneKey() {
184 return std::make_pair(FirstInfo::getTombstoneKey(),
185 SecondInfo::getTombstoneKey());
186 }
187
188 static unsigned getHashValue(const Pair& PairVal) {
189 uint64_t key = (uint64_t)FirstInfo::getHashValue(PairVal.first) << 32
190 | (uint64_t)SecondInfo::getHashValue(PairVal.second);
191 key += ~(key << 32);
192 key ^= (key >> 22);
193 key += ~(key << 13);
194 key ^= (key >> 8);
195 key += (key << 3);
196 key ^= (key >> 15);
197 key += ~(key << 27);
198 key ^= (key >> 31);
199 return (unsigned)key;
200 }
201
202 static bool isEqual(const Pair &LHS, const Pair &RHS) {
203 return FirstInfo::isEqual(LHS.first, RHS.first) &&
204 SecondInfo::isEqual(LHS.second, RHS.second);
205 }
206};
207
208// Provide DenseMapInfo for StringRefs.
209template <> struct DenseMapInfo<StringRef> {
210 static inline StringRef getEmptyKey() {
211 return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)),
212 0);
213 }
214
215 static inline StringRef getTombstoneKey() {
216 return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
217 0);
218 }
219
220 static unsigned getHashValue(StringRef Val) {
221 assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
222 assert(Val.data() != getTombstoneKey().data() &&
223 "Cannot hash the tombstone key!");
224 return (unsigned)(hash_value(Val));
225 }
226
227 static bool isEqual(StringRef LHS, StringRef RHS) {
228 if (RHS.data() == getEmptyKey().data())
229 return LHS.data() == getEmptyKey().data();
230 if (RHS.data() == getTombstoneKey().data())
231 return LHS.data() == getTombstoneKey().data();
232 return LHS == RHS;
233 }
234};
235
236// Provide DenseMapInfo for ArrayRefs.
237template <typename T> struct DenseMapInfo<ArrayRef<T>> {
238 static inline ArrayRef<T> getEmptyKey() {
239 return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(0)),
240 size_t(0));
241 }
242
243 static inline ArrayRef<T> getTombstoneKey() {
244 return ArrayRef<T>(reinterpret_cast<const T *>(~static_cast<uintptr_t>(1)),
245 size_t(0));
246 }
247
248 static unsigned getHashValue(ArrayRef<T> Val) {
249 assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
250 assert(Val.data() != getTombstoneKey().data() &&
251 "Cannot hash the tombstone key!");
252 return (unsigned)(hash_value(Val));
253 }
254
255 static bool isEqual(ArrayRef<T> LHS, ArrayRef<T> RHS) {
256 if (RHS.data() == getEmptyKey().data())
257 return LHS.data() == getEmptyKey().data();
258 if (RHS.data() == getTombstoneKey().data())
259 return LHS.data() == getTombstoneKey().data();
260 return LHS == RHS;
261 }
262};
263
264template <> struct DenseMapInfo<hash_code> {
265 static inline hash_code getEmptyKey() { return hash_code(-1); }
266 static inline hash_code getTombstoneKey() { return hash_code(-2); }
267 static unsigned getHashValue(hash_code val) { return val; }
268 static bool isEqual(hash_code LHS, hash_code RHS) { return LHS == RHS; }
269};
270
271} // end namespace llvm
272
273#endif // LLVM_ADT_DENSEMAPINFO_H
274