#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;
+
/// 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.
+///
+/// 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>
+template <typename PointerTy, unsigned IntBits, typename IntType=unsigned,
+ typename PtrTraits = PointerLikeTypeTraits<PointerTy> >
class PointerIntPair {
intptr_t Value;
+ 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)
+ };
+
public:
PointerIntPair() : Value(0) {}
- PointerIntPair(PointerTy Ptr, IntType Int) : Value(0) {
- setPointer(Ptr);
- setInt(Int);
+ PointerIntPair(PointerTy PtrVal, IntType IntVal) {
+ setPointerAndInt(PtrVal, IntVal);
+ }
+ explicit PointerIntPair(PointerTy PtrVal) {
+ initWithPointer(PtrVal);
}
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 PtrVal) {
+ intptr_t PtrWord
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal));
+ assert((PtrWord & ~PointerBitMask) == 0 &&
+ "Pointer is not sufficiently aligned");
+ // Preserve all low bits, just update the pointer.
+ Value = PtrWord | (Value & ~PointerBitMask);
+ }
+
+ void setInt(IntType IntVal) {
+ intptr_t IntWord = static_cast<intptr_t>(IntVal);
+ assert((IntWord & ~IntMask) == 0 && "Integer too large for field");
+
+ // Preserve all bits other than the ones we are updating.
+ Value &= ~ShiftedIntMask; // Remove integer field.
+ Value |= IntWord << IntShift; // Set new integer.
+ }
+
+ void initWithPointer(PointerTy PtrVal) {
+ intptr_t PtrWord
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal));
+ assert((PtrWord & ~PointerBitMask) == 0 &&
+ "Pointer is not sufficiently aligned");
+ Value = PtrWord;
+ }
+
+ void setPointerAndInt(PointerTy PtrVal, IntType IntVal) {
+ intptr_t PtrWord
+ = reinterpret_cast<intptr_t>(PtrTraits::getAsVoidPointer(PtrVal));
+ assert((PtrWord & ~PointerBitMask) == 0 &&
+ "Pointer is not sufficiently aligned");
+ intptr_t IntWord = static_cast<intptr_t>(IntVal);
+ assert((IntWord & ~IntMask) == 0 && "Integer too large for field");
+
+ Value = PtrWord | (IntWord << IntShift);
}
-
- void setPointer(PointerTy Ptr) {
- intptr_t PtrVal = reinterpret_cast<intptr_t>(Ptr);
- assert((PtrVal & (1 << IntBits)-1) == 0 &&
- "Pointer is no sufficiently aligned");
- Value = PtrVal | (intptr_t)getInt();
+
+ PointerTy const *getAddrOfPointer() const {
+ return const_cast<PointerIntPair *>(this)->getAddrOfPointer();
}
-
- void setInt(IntType Int) {
- assert(Int < (1 << IntBits) && "Integer too large for field");
- Value = reinterpret_cast<intptr_t>(getPointer()) | (intptr_t)Int;
+
+ 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);}
-
- bool operator==(const PointerIntPair &RHS) const {
- return Value == RHS.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;}
+ 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() {
+ 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);
}
- bool operator!=(const PointerIntPair &RHS) const {
- return Value != RHS.Value;
+ 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
projects / oota-llvm.git / blobdiff