llvm-6502/include/llvm/ADT/DenseMapInfo.h
Dan Gohman fb3af88ba7 Split DenseMapInfo into a separate header file, so that it can be
included separately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77693 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-31 18:18:19 +00:00

122 lines
3.9 KiB
C++

//===- llvm/ADT/DenseMapInfo.h - Type traits for DenseMap -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines DenseMapInfo traits for DenseMap.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_DENSEMAPINFO_H
#define LLVM_ADT_DENSEMAPINFO_H
#include "llvm/Support/PointerLikeTypeTraits.h"
#include <utility>
namespace llvm {
template<typename T>
struct DenseMapInfo {
//static inline T getEmptyKey();
//static inline T getTombstoneKey();
//static unsigned getHashValue(const T &Val);
//static bool isEqual(const T &LHS, const T &RHS);
//static bool isPod()
};
// Provide DenseMapInfo for all pointers.
template<typename T>
struct DenseMapInfo<T*> {
static inline T* getEmptyKey() {
intptr_t Val = -1;
Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
return reinterpret_cast<T*>(Val);
}
static inline T* getTombstoneKey() {
intptr_t Val = -2;
Val <<= PointerLikeTypeTraits<T*>::NumLowBitsAvailable;
return reinterpret_cast<T*>(Val);
}
static unsigned getHashValue(const T *PtrVal) {
return (unsigned((uintptr_t)PtrVal) >> 4) ^
(unsigned((uintptr_t)PtrVal) >> 9);
}
static bool isEqual(const T *LHS, const T *RHS) { return LHS == RHS; }
static bool isPod() { return true; }
};
// Provide DenseMapInfo for chars.
template<> struct DenseMapInfo<char> {
static inline char getEmptyKey() { return ~0; }
static inline char getTombstoneKey() { return ~0 - 1; }
static unsigned getHashValue(const char& Val) { return Val * 37; }
static bool isPod() { return true; }
static bool isEqual(const char &LHS, const char &RHS) {
return LHS == RHS;
}
};
// Provide DenseMapInfo for unsigned ints.
template<> struct DenseMapInfo<unsigned> {
static inline unsigned getEmptyKey() { return ~0; }
static inline unsigned getTombstoneKey() { return ~0 - 1; }
static unsigned getHashValue(const unsigned& Val) { return Val * 37; }
static bool isPod() { return true; }
static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
return LHS == RHS;
}
};
// Provide DenseMapInfo for unsigned longs.
template<> struct DenseMapInfo<unsigned long> {
static inline unsigned long getEmptyKey() { return ~0L; }
static inline unsigned long getTombstoneKey() { return ~0L - 1L; }
static unsigned getHashValue(const unsigned long& Val) {
return (unsigned)(Val * 37L);
}
static bool isPod() { return true; }
static bool isEqual(const unsigned long& LHS, const unsigned long& RHS) {
return LHS == RHS;
}
};
// Provide DenseMapInfo for all pairs whose members have info.
template<typename T, typename U>
struct DenseMapInfo<std::pair<T, U> > {
typedef std::pair<T, U> Pair;
typedef DenseMapInfo<T> FirstInfo;
typedef DenseMapInfo<U> SecondInfo;
static inline Pair getEmptyKey() {
return std::make_pair(FirstInfo::getEmptyKey(),
SecondInfo::getEmptyKey());
}
static inline Pair getTombstoneKey() {
return std::make_pair(FirstInfo::getTombstoneKey(),
SecondInfo::getEmptyKey());
}
static unsigned getHashValue(const Pair& PairVal) {
uint64_t key = (uint64_t)FirstInfo::getHashValue(PairVal.first) << 32
| (uint64_t)SecondInfo::getHashValue(PairVal.second);
key += ~(key << 32);
key ^= (key >> 22);
key += ~(key << 13);
key ^= (key >> 8);
key += (key << 3);
key ^= (key >> 15);
key += ~(key << 27);
key ^= (key >> 31);
return (unsigned)key;
}
static bool isEqual(const Pair& LHS, const Pair& RHS) { return LHS == RHS; }
static bool isPod() { return FirstInfo::isPod() && SecondInfo::isPod(); }
};
} // end namespace llvm
#endif