#ifndef LLVM_ADT_POINTERINTPAIR_H
#define LLVM_ADT_POINTERINTPAIR_H
-#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
#include <cassert>
namespace llvm {
template<typename T>
struct DenseMapInfo;
-template<typename>
-class PointerLikeTypeInfo;
/// 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 alignment returned by the allocator in use.
+/// on the number of bits available according to PointerLikeTypeTraits for the
+/// type.
///
-template <typename PointerTy, unsigned IntBits, typename IntType=unsigned>
+/// Note that PointerIntPair always puts the Int 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> >
class PointerIntPair {
intptr_t Value;
+ enum {
+ /// 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)
+ };
public:
PointerIntPair() : Value(0) {}
- PointerIntPair(PointerTy Ptr, IntType Int) : Value(0) {
- setPointer(Ptr);
- setInt(Int);
+ PointerIntPair(PointerTy Ptr, IntType Int) {
+ assert(IntBits <= PtrTraits::NumLowBitsAvailable &&
+ "PointerIntPair formed with integer size too large for pointer");
+ setPointerAndInt(Ptr, Int);
+ }
+ explicit PointerIntPair(PointerTy Ptr) {
+ initWithPointer(Ptr);
}
PointerTy getPointer() const {
- return reinterpret_cast<PointerTy>(Value & ~((1 << IntBits)-1));
+ return PtrTraits::getFromVoidPointer(
+ reinterpret_cast<void*>(Value & PointerBitMask));
}
IntType getInt() const {
- return (IntType)(Value & ((1 << IntBits)-1));
+ return (IntType)((Value >> IntShift) & IntMask);
}
void setPointer(PointerTy Ptr) {
- intptr_t PtrVal = reinterpret_cast<intptr_t>(Ptr);
- assert((PtrVal & ((1 << IntBits)-1)) == 0 &&
+ intptr_t PtrVal
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
+ assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
"Pointer is not sufficiently aligned");
- Value = PtrVal | (intptr_t)getInt();
+ // Preserve all low bits, just update the pointer.
+ Value = PtrVal | (Value & ~PointerBitMask);
}
void setInt(IntType Int) {
intptr_t IntVal = Int;
assert(IntVal < (1 << IntBits) && "Integer too large for field");
- Value = reinterpret_cast<intptr_t>(getPointer()) | IntVal;
+
+ // Preserve all bits other than the ones we are updating.
+ Value &= ~ShiftedIntMask; // Remove integer field.
+ Value |= IntVal << IntShift; // Set new integer.
+ }
+
+ void initWithPointer(PointerTy Ptr) {
+ intptr_t PtrVal
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
+ assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
+ "Pointer is not sufficiently aligned");
+ Value = PtrVal;
+ }
+
+ void setPointerAndInt(PointerTy Ptr, IntType Int) {
+ intptr_t PtrVal
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(Ptr));
+ assert((PtrVal & ((1 << PtrTraits::NumLowBitsAvailable)-1)) == 0 &&
+ "Pointer is not sufficiently aligned");
+ intptr_t IntVal = Int;
+ assert(IntVal < (1 << IntBits) && "Integer too large for field");
+
+ Value = PtrVal | (IntVal << IntShift);
+ }
+
+ 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); }
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;}
};
+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() {
- return Ty(reinterpret_cast<PointerTy>(-1 << IntBits),
- IntType((1 << IntBits)-1));
+ uintptr_t Val = static_cast<uintptr_t>(-1);
+ Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
+ return Ty(reinterpret_cast<PointerTy>(Val), IntType((1 << IntBits)-1));
}
static Ty getTombstoneKey() {
- return Ty(reinterpret_cast<PointerTy>(-2 << IntBits), IntType(0));
+ uintptr_t Val = static_cast<uintptr_t>(-2);
+ Val <<= PointerLikeTypeTraits<PointerTy>::NumLowBitsAvailable;
+ return Ty(reinterpret_cast<PointerTy>(Val), IntType(0));
}
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; }
- static bool isPod() { return true; }
};
// Teach SmallPtrSet that PointerIntPair is "basically a pointer".
-template<typename PointerTy, unsigned IntBits, typename IntType>
-class PointerLikeTypeInfo<PointerIntPair<PointerTy, IntBits, IntType> > {
+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) {
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