/usr/include/llvm-3.9/llvm/ADT/PointerIntPair.h is in llvm-3.9-dev 1:3.9.1-19ubuntu1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 | //===- llvm/ADT/PointerIntPair.h - Pair for pointer and int -----*- 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 the PointerIntPair class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_POINTERINTPAIR_H
#define LLVM_ADT_POINTERINTPAIR_H
#include "llvm/Support/Compiler.h"
#include "llvm/Support/PointerLikeTypeTraits.h"
#include <cassert>
#include <limits>
namespace llvm {
template <typename T> struct DenseMapInfo;
template <typename PointerT, unsigned IntBits, typename PtrTraits>
struct PointerIntPairInfo;
/// PointerIntPair - This class implements a pair of a pointer and small
/// integer. It is designed to represent this in the space required by one
/// pointer by bitmangling the integer into the low part of the pointer. This
/// can only be done for small integers: typically up to 3 bits, but it depends
/// on the number of bits available according to PointerLikeTypeTraits for the
/// type.
///
/// Note that PointerIntPair always puts the IntVal part in the highest bits
/// possible. For example, PointerIntPair<void*, 1, bool> will put the bit for
/// the bool into bit #2, not bit #0, which allows the low two bits to be used
/// for something else. For example, this allows:
/// PointerIntPair<PointerIntPair<void*, 1, bool>, 1, bool>
/// ... and the two bools will land in different bits.
///
template <typename PointerTy, unsigned IntBits, typename IntType = unsigned,
typename PtrTraits = PointerLikeTypeTraits<PointerTy>,
typename Info = PointerIntPairInfo<PointerTy, IntBits, PtrTraits>>
class PointerIntPair {
intptr_t Value;
public:
PointerIntPair() : Value(0) {}
PointerIntPair(PointerTy PtrVal, IntType IntVal) {
setPointerAndInt(PtrVal, IntVal);
}
explicit PointerIntPair(PointerTy PtrVal) { initWithPointer(PtrVal); }
PointerTy getPointer() const { return Info::getPointer(Value); }
IntType getInt() const {
return (IntType)Info::getInt(Value);
}
void setPointer(PointerTy PtrVal) {
Value = Info::updatePointer(Value, PtrVal);
}
void setInt(IntType IntVal) {
Value = Info::updateInt(Value, static_cast<intptr_t>(IntVal));
}
void initWithPointer(PointerTy PtrVal) {
Value = Info::updatePointer(0, PtrVal);
}
void setPointerAndInt(PointerTy PtrVal, IntType IntVal) {
Value = Info::updateInt(Info::updatePointer(0, PtrVal),
static_cast<intptr_t>(IntVal));
}
PointerTy const *getAddrOfPointer() const {
return const_cast<PointerIntPair *>(this)->getAddrOfPointer();
}
PointerTy *getAddrOfPointer() {
assert(Value == reinterpret_cast<intptr_t>(getPointer()) &&
"Can only return the address if IntBits is cleared and "
"PtrTraits doesn't change the pointer");
return reinterpret_cast<PointerTy *>(&Value);
}
void *getOpaqueValue() const { return reinterpret_cast<void *>(Value); }
void setFromOpaqueValue(void *Val) {
Value = reinterpret_cast<intptr_t>(Val);
}
static PointerIntPair getFromOpaqueValue(void *V) {
PointerIntPair P;
P.setFromOpaqueValue(V);
return P;
}
// Allow PointerIntPairs to be created from const void * if and only if the
// pointer type could be created from a const void *.
static PointerIntPair getFromOpaqueValue(const void *V) {
(void)PtrTraits::getFromVoidPointer(V);
return getFromOpaqueValue(const_cast<void *>(V));
}
bool operator==(const PointerIntPair &RHS) const {
return Value == RHS.Value;
}
bool operator!=(const PointerIntPair &RHS) const {
return Value != RHS.Value;
}
bool operator<(const PointerIntPair &RHS) const { return Value < RHS.Value; }
bool operator>(const PointerIntPair &RHS) const { return Value > RHS.Value; }
bool operator<=(const PointerIntPair &RHS) const {
return Value <= RHS.Value;
}
bool operator>=(const PointerIntPair &RHS) const {
return Value >= RHS.Value;
}
};
template <typename PointerT, unsigned IntBits, typename PtrTraits>
struct PointerIntPairInfo {
static_assert(PtrTraits::NumLowBitsAvailable <
std::numeric_limits<uintptr_t>::digits,
"cannot use a pointer type that has all bits free");
static_assert(IntBits <= PtrTraits::NumLowBitsAvailable,
"PointerIntPair with integer size too large for pointer");
enum : uintptr_t {
/// PointerBitMask - The bits that come from the pointer.
PointerBitMask =
~(uintptr_t)(((intptr_t)1 << PtrTraits::NumLowBitsAvailable) - 1),
/// IntShift - The number of low bits that we reserve for other uses, and
/// keep zero.
IntShift = (uintptr_t)PtrTraits::NumLowBitsAvailable - IntBits,
/// IntMask - This is the unshifted mask for valid bits of the int type.
IntMask = (uintptr_t)(((intptr_t)1 << IntBits) - 1),
// ShiftedIntMask - This is the bits for the integer shifted in place.
ShiftedIntMask = (uintptr_t)(IntMask << IntShift)
};
static PointerT getPointer(intptr_t Value) {
return PtrTraits::getFromVoidPointer(
reinterpret_cast<void *>(Value & PointerBitMask));
}
static intptr_t getInt(intptr_t Value) {
return (Value >> IntShift) & IntMask;
}
static intptr_t updatePointer(intptr_t OrigValue, PointerT Ptr) {
intptr_t PtrWord =
reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
assert((PtrWord & ~PointerBitMask) == 0 &&
"Pointer is not sufficiently aligned");
// Preserve all low bits, just update the pointer.
return PtrWord | (OrigValue & ~PointerBitMask);
}
static intptr_t updateInt(intptr_t OrigValue, intptr_t Int) {
intptr_t IntWord = static_cast<intptr_t>(Int);
assert((IntWord & ~IntMask) == 0 && "Integer too large for field");
// Preserve all bits other than the ones we are updating.
return (OrigValue & ~ShiftedIntMask) | IntWord << IntShift;
}
};
template <typename T> struct isPodLike;
template <typename PointerTy, unsigned IntBits, typename IntType>
struct isPodLike<PointerIntPair<PointerTy, IntBits, IntType>> {
static const bool value = true;
};
// Provide specialization of DenseMapInfo for PointerIntPair.
template <typename PointerTy, unsigned IntBits, typename IntType>
struct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType>> {
typedef PointerIntPair<PointerTy, IntBits, IntType> Ty;
static Ty getEmptyKey() {
uintptr_t Val = static_cast<uintptr_t>(-1);
Val <<= PointerLikeTypeTraits<Ty>::NumLowBitsAvailable;
return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
}
static Ty getTombstoneKey() {
uintptr_t Val = static_cast<uintptr_t>(-2);
Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
return Ty::getFromOpaqueValue(reinterpret_cast<void *>(Val));
}
static unsigned getHashValue(Ty V) {
uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue());
return unsigned(IV) ^ unsigned(IV >> 9);
}
static bool isEqual(const Ty &LHS, const Ty &RHS) { return LHS == RHS; }
};
// Teach SmallPtrSet that PointerIntPair is "basically a pointer".
template <typename PointerTy, unsigned IntBits, typename IntType,
typename PtrTraits>
class PointerLikeTypeTraits<
PointerIntPair<PointerTy, IntBits, IntType, PtrTraits>> {
public:
static inline void *
getAsVoidPointer(const PointerIntPair<PointerTy, IntBits, IntType> &P) {
return P.getOpaqueValue();
}
static inline PointerIntPair<PointerTy, IntBits, IntType>
getFromVoidPointer(void *P) {
return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
}
static inline PointerIntPair<PointerTy, IntBits, IntType>
getFromVoidPointer(const void *P) {
return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P);
}
enum { NumLowBitsAvailable = PtrTraits::NumLowBitsAvailable - IntBits };
};
} // end namespace llvm
#endif
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