1 //===- llvm/ADT/DenseMapInfo.h - Type traits for DenseMap -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines DenseMapInfo traits for DenseMap.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ADT_DENSEMAPINFO_H
15 #define LLVM_ADT_DENSEMAPINFO_H
17 #include "llvm/Support/PointerLikeTypeTraits.h"
18 #include "llvm/Support/type_traits.h"
24 //static inline T getEmptyKey();
25 //static inline T getTombstoneKey();
26 //static unsigned getHashValue(const T &Val);
27 //static bool isEqual(const T &LHS, const T &RHS);
30 // Provide DenseMapInfo for all pointers.
32 struct DenseMapInfo<T*> {
33 static inline T* getEmptyKey() {
35 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
36 return reinterpret_cast<T*>(Val);
38 static inline T* getTombstoneKey() {
40 Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
41 return reinterpret_cast<T*>(Val);
43 static unsigned getHashValue(const T *PtrVal) {
44 return (unsigned((uintptr_t)PtrVal) >> 4) ^
45 (unsigned((uintptr_t)PtrVal) >> 9);
47 static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
50 // Provide DenseMapInfo for chars.
51 template<> struct DenseMapInfo<char> {
52 static inline char getEmptyKey() { return ~0; }
53 static inline char getTombstoneKey() { return ~0 - 1; }
54 static unsigned getHashValue(const char& Val) { return Val * 37; }
55 static bool isEqual(const char &LHS, const char &RHS) {
60 // Provide DenseMapInfo for unsigned ints.
61 template<> struct DenseMapInfo<unsigned> {
62 static inline unsigned getEmptyKey() { return ~0; }
63 static inline unsigned getTombstoneKey() { return ~0U - 1; }
64 static unsigned getHashValue(const unsigned& Val) { return Val * 37; }
65 static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
70 // Provide DenseMapInfo for unsigned longs.
71 template<> struct DenseMapInfo<unsigned long> {
72 static inline unsigned long getEmptyKey() { return ~0UL; }
73 static inline unsigned long getTombstoneKey() { return ~0UL - 1L; }
74 static unsigned getHashValue(const unsigned long& Val) {
75 return (unsigned)(Val * 37UL);
77 static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
82 // Provide DenseMapInfo for unsigned long longs.
83 template<> struct DenseMapInfo<unsigned long long> {
84 static inline unsigned long long getEmptyKey() { return ~0ULL; }
85 static inline unsigned long long getTombstoneKey() { return ~0ULL - 1ULL; }
86 static unsigned getHashValue(const unsigned long long& Val) {
87 return (unsigned)(Val * 37ULL);
89 static bool isEqual(const unsigned long long& LHS,
90 const unsigned long long& RHS) {
95 // Provide DenseMapInfo for long longs.
96 template<> struct DenseMapInfo<long long> {
97 static inline long long getEmptyKey() { return 0x7fffffffffffffffLL; }
98 static inline long long getTombstoneKey() { return -0x7fffffffffffffffLL-1; }
99 static unsigned getHashValue(const long long& Val) {
100 return (unsigned)(Val * 37LL);
102 static bool isEqual(const long long& LHS,
103 const long long& RHS) {
108 // Provide DenseMapInfo for all pairs whose members have info.
109 template<typename T, typename U>
110 struct DenseMapInfo<std::pair<T, U> > {
111 typedef std::pair<T, U> Pair;
112 typedef DenseMapInfo<T> FirstInfo;
113 typedef DenseMapInfo<U> SecondInfo;
115 static inline Pair getEmptyKey() {
116 return std::make_pair(FirstInfo::getEmptyKey(),
117 SecondInfo::getEmptyKey());
119 static inline Pair getTombstoneKey() {
120 return std::make_pair(FirstInfo::getTombstoneKey(),
121 SecondInfo::getEmptyKey());
123 static unsigned getHashValue(const Pair& PairVal) {
124 uint64_t key = (uint64_t)FirstInfo::getHashValue(PairVal.first) << 32
125 | (uint64_t)SecondInfo::getHashValue(PairVal.second);
134 return (unsigned)key;
136 static bool isEqual(const Pair& LHS, const Pair& RHS) { return LHS == RHS; }
139 } // end namespace llvm