1193323Sed//===- llvm/ADT/PointerIntPair.h - Pair for pointer and int -----*- C++ -*-===// 2193323Sed// 3193323Sed// The LLVM Compiler Infrastructure 4193323Sed// 5193323Sed// This file is distributed under the University of Illinois Open Source 6193323Sed// License. See LICENSE.TXT for details. 7193323Sed// 8193323Sed//===----------------------------------------------------------------------===// 9193323Sed// 10193323Sed// This file defines the PointerIntPair class. 11193323Sed// 12193323Sed//===----------------------------------------------------------------------===// 13193323Sed 14193323Sed#ifndef LLVM_ADT_POINTERINTPAIR_H 15193323Sed#define LLVM_ADT_POINTERINTPAIR_H 16193323Sed 17193323Sed#include "llvm/Support/PointerLikeTypeTraits.h" 18193323Sed#include <cassert> 19193323Sed 20193323Sednamespace llvm { 21193323Sed 22193323Sedtemplate<typename T> 23193323Sedstruct DenseMapInfo; 24193323Sed 25193323Sed/// PointerIntPair - This class implements a pair of a pointer and small 26193323Sed/// integer. It is designed to represent this in the space required by one 27193323Sed/// pointer by bitmangling the integer into the low part of the pointer. This 28193323Sed/// can only be done for small integers: typically up to 3 bits, but it depends 29193323Sed/// on the number of bits available according to PointerLikeTypeTraits for the 30193323Sed/// type. 31193323Sed/// 32251662Sdim/// Note that PointerIntPair always puts the IntVal part in the highest bits 33193323Sed/// possible. For example, PointerIntPair<void*, 1, bool> will put the bit for 34193323Sed/// the bool into bit #2, not bit #0, which allows the low two bits to be used 35193323Sed/// for something else. For example, this allows: 36193323Sed/// PointerIntPair<PointerIntPair<void*, 1, bool>, 1, bool> 37193323Sed/// ... and the two bools will land in different bits. 38193323Sed/// 39193323Sedtemplate <typename PointerTy, unsigned IntBits, typename IntType=unsigned, 40193323Sed typename PtrTraits = PointerLikeTypeTraits<PointerTy> > 41193323Sedclass PointerIntPair { 42193323Sed intptr_t Value; 43193323Sed enum { 44193323Sed /// PointerBitMask - The bits that come from the pointer. 45193323Sed PointerBitMask = 46193323Sed ~(uintptr_t)(((intptr_t)1 << PtrTraits::NumLowBitsAvailable)-1), 47193323Sed 48193323Sed /// IntShift - The number of low bits that we reserve for other uses, and 49193323Sed /// keep zero. 50193323Sed IntShift = (uintptr_t)PtrTraits::NumLowBitsAvailable-IntBits, 51193323Sed 52193323Sed /// IntMask - This is the unshifted mask for valid bits of the int type. 53193323Sed IntMask = (uintptr_t)(((intptr_t)1 << IntBits)-1), 54193323Sed 55193323Sed // ShiftedIntMask - This is the bits for the integer shifted in place. 56193323Sed ShiftedIntMask = (uintptr_t)(IntMask << IntShift) 57193323Sed }; 58193323Sedpublic: 59193323Sed PointerIntPair() : Value(0) {} 60251662Sdim PointerIntPair(PointerTy PtrVal, IntType IntVal) { 61193323Sed assert(IntBits <= PtrTraits::NumLowBitsAvailable && 62193323Sed "PointerIntPair formed with integer size too large for pointer"); 63251662Sdim setPointerAndInt(PtrVal, IntVal); 64193323Sed } 65251662Sdim explicit PointerIntPair(PointerTy PtrVal) { 66251662Sdim initWithPointer(PtrVal); 67249423Sdim } 68193323Sed 69193323Sed PointerTy getPointer() const { 70198090Srdivacky return PtrTraits::getFromVoidPointer( 71198090Srdivacky reinterpret_cast<void*>(Value & PointerBitMask)); 72193323Sed } 73193323Sed 74193323Sed IntType getInt() const { 75193323Sed return (IntType)((Value >> IntShift) & IntMask); 76193323Sed } 77193323Sed 78251662Sdim void setPointer(PointerTy PtrVal) { 79251662Sdim intptr_t PtrWord 80251662Sdim = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal)); 81251662Sdim assert((PtrWord & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 && 82193323Sed "Pointer is not sufficiently aligned"); 83193323Sed // Preserve all low bits, just update the pointer. 84251662Sdim Value = PtrWord | (Value & ~PointerBitMask); 85193323Sed } 86193323Sed 87251662Sdim void setInt(IntType IntVal) { 88251662Sdim intptr_t IntWord = static_cast<intptr_t>(IntVal); 89251662Sdim assert(IntWord < (1 << IntBits) && "Integer too large for field"); 90193323Sed 91193323Sed // Preserve all bits other than the ones we are updating. 92193323Sed Value &= ~ShiftedIntMask; // Remove integer field. 93251662Sdim Value |= IntWord << IntShift; // Set new integer. 94193323Sed } 95193323Sed 96251662Sdim void initWithPointer(PointerTy PtrVal) { 97251662Sdim intptr_t PtrWord 98251662Sdim = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal)); 99251662Sdim assert((PtrWord & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 && 100249423Sdim "Pointer is not sufficiently aligned"); 101251662Sdim Value = PtrWord; 102249423Sdim } 103249423Sdim 104251662Sdim void setPointerAndInt(PointerTy PtrVal, IntType IntVal) { 105251662Sdim intptr_t PtrWord 106251662Sdim = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal)); 107251662Sdim assert((PtrWord & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 && 108249423Sdim "Pointer is not sufficiently aligned"); 109251662Sdim intptr_t IntWord = static_cast<intptr_t>(IntVal); 110251662Sdim assert(IntWord < (1 << IntBits) && "Integer too large for field"); 111249423Sdim 112251662Sdim Value = PtrWord | (IntWord << IntShift); 113249423Sdim } 114249423Sdim 115218893Sdim PointerTy const *getAddrOfPointer() const { 116234353Sdim return const_cast<PointerIntPair *>(this)->getAddrOfPointer(); 117234353Sdim } 118234353Sdim 119234353Sdim PointerTy *getAddrOfPointer() { 120218893Sdim assert(Value == reinterpret_cast<intptr_t>(getPointer()) && 121218893Sdim "Can only return the address if IntBits is cleared and " 122218893Sdim "PtrTraits doesn't change the pointer"); 123234353Sdim return reinterpret_cast<PointerTy *>(&Value); 124218893Sdim } 125218893Sdim 126193323Sed void *getOpaqueValue() const { return reinterpret_cast<void*>(Value); } 127193323Sed void setFromOpaqueValue(void *Val) { Value = reinterpret_cast<intptr_t>(Val);} 128193323Sed 129193323Sed static PointerIntPair getFromOpaqueValue(void *V) { 130193323Sed PointerIntPair P; P.setFromOpaqueValue(V); return P; 131193323Sed } 132239462Sdim 133239462Sdim // Allow PointerIntPairs to be created from const void * if and only if the 134239462Sdim // pointer type could be created from a const void *. 135239462Sdim static PointerIntPair getFromOpaqueValue(const void *V) { 136239462Sdim (void)PtrTraits::getFromVoidPointer(V); 137239462Sdim return getFromOpaqueValue(const_cast<void *>(V)); 138239462Sdim } 139239462Sdim 140193323Sed bool operator==(const PointerIntPair &RHS) const {return Value == RHS.Value;} 141193323Sed bool operator!=(const PointerIntPair &RHS) const {return Value != RHS.Value;} 142193323Sed bool operator<(const PointerIntPair &RHS) const {return Value < RHS.Value;} 143193323Sed bool operator>(const PointerIntPair &RHS) const {return Value > RHS.Value;} 144193323Sed bool operator<=(const PointerIntPair &RHS) const {return Value <= RHS.Value;} 145193323Sed bool operator>=(const PointerIntPair &RHS) const {return Value >= RHS.Value;} 146193323Sed}; 147193323Sed 148200581Srdivackytemplate <typename T> struct isPodLike; 149200581Srdivackytemplate<typename PointerTy, unsigned IntBits, typename IntType> 150200581Srdivackystruct isPodLike<PointerIntPair<PointerTy, IntBits, IntType> > { 151200581Srdivacky static const bool value = true; 152200581Srdivacky}; 153200581Srdivacky 154193323Sed// Provide specialization of DenseMapInfo for PointerIntPair. 155193323Sedtemplate<typename PointerTy, unsigned IntBits, typename IntType> 156193323Sedstruct DenseMapInfo<PointerIntPair<PointerTy, IntBits, IntType> > { 157193323Sed typedef PointerIntPair<PointerTy, IntBits, IntType> Ty; 158193323Sed static Ty getEmptyKey() { 159243830Sdim uintptr_t Val = static_cast<uintptr_t>(-1); 160193323Sed Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable; 161193323Sed return Ty(reinterpret_cast<PointerTy>(Val), IntType((1 << IntBits)-1)); 162193323Sed } 163193323Sed static Ty getTombstoneKey() { 164243830Sdim uintptr_t Val = static_cast<uintptr_t>(-2); 165193323Sed Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable; 166193323Sed return Ty(reinterpret_cast<PointerTy>(Val), IntType(0)); 167193323Sed } 168193323Sed static unsigned getHashValue(Ty V) { 169193323Sed uintptr_t IV = reinterpret_cast<uintptr_t>(V.getOpaqueValue()); 170193323Sed return unsigned(IV) ^ unsigned(IV >> 9); 171193323Sed } 172193323Sed static bool isEqual(const Ty &LHS, const Ty &RHS) { return LHS == RHS; } 173193323Sed}; 174193323Sed 175193323Sed// Teach SmallPtrSet that PointerIntPair is "basically a pointer". 176193323Sedtemplate<typename PointerTy, unsigned IntBits, typename IntType, 177193323Sed typename PtrTraits> 178193323Sedclass PointerLikeTypeTraits<PointerIntPair<PointerTy, IntBits, IntType, 179193323Sed PtrTraits> > { 180193323Sedpublic: 181193323Sed static inline void * 182193323Sed getAsVoidPointer(const PointerIntPair<PointerTy, IntBits, IntType> &P) { 183193323Sed return P.getOpaqueValue(); 184193323Sed } 185193323Sed static inline PointerIntPair<PointerTy, IntBits, IntType> 186193323Sed getFromVoidPointer(void *P) { 187193323Sed return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P); 188193323Sed } 189239462Sdim static inline PointerIntPair<PointerTy, IntBits, IntType> 190239462Sdim getFromVoidPointer(const void *P) { 191239462Sdim return PointerIntPair<PointerTy, IntBits, IntType>::getFromOpaqueValue(P); 192239462Sdim } 193193323Sed enum { 194198090Srdivacky NumLowBitsAvailable = PtrTraits::NumLowBitsAvailable - IntBits 195193323Sed }; 196193323Sed}; 197193323Sed 198193323Sed} // end namespace llvm 199193323Sed#endif 200