//
// The LLVM Compiler Infrastructure
//
-// This file was developed by Chris Lattner and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the SmallPtrSet class. See the doxygen comment for
-// SmallPtrSetImpl for more details on the algorithm used.
+// SmallPtrSetImplBase for more details on the algorithm used.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_SMALLPTRSET_H
#define LLVM_ADT_SMALLPTRSET_H
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
#include <cassert>
+#include <cstddef>
#include <cstring>
-#include "llvm/Support/DataTypes.h"
+#include <iterator>
+#include <utility>
namespace llvm {
-/// SmallPtrSetImpl - This is the common code shared among all the
+class SmallPtrSetIteratorImpl;
+
+/// SmallPtrSetImplBase - This is the common code shared among all the
/// SmallPtrSet<>'s, which is almost everything. SmallPtrSet has two modes, one
/// for small and one for large sets.
///
/// (-2), to allow deletion. The hash table is resized when the table is 3/4 or
/// more. When this happens, the table is doubled in size.
///
-class SmallPtrSetImpl {
+class SmallPtrSetImplBase {
+ friend class SmallPtrSetIteratorImpl;
protected:
- /// CurArray - This is the current set of buckets. If it points to
- /// SmallArray, then the set is in 'small mode'.
- void **CurArray;
+ /// SmallArray - Points to a fixed size set of buckets, used in 'small mode'.
+ const void **SmallArray;
+ /// CurArray - This is the current set of buckets. If equal to SmallArray,
+ /// then the set is in 'small mode'.
+ const void **CurArray;
/// CurArraySize - The allocated size of CurArray, always a power of two.
- /// Note that CurArray points to an array that has CurArraySize+1 elements in
- /// it, so that the end iterator actually points to valid memory.
unsigned CurArraySize;
-
- // If small, this is # elts allocated consequtively
+
+ // If small, this is # elts allocated consecutively
unsigned NumElements;
unsigned NumTombstones;
- void *SmallArray[1]; // Must be last ivar.
-public:
- SmallPtrSetImpl(unsigned SmallSize) {
+
+ // Helpers to copy and move construct a SmallPtrSet.
+ SmallPtrSetImplBase(const void **SmallStorage, const SmallPtrSetImplBase &that);
+ SmallPtrSetImplBase(const void **SmallStorage, unsigned SmallSize,
+ SmallPtrSetImplBase &&that);
+ explicit SmallPtrSetImplBase(const void **SmallStorage, unsigned SmallSize) :
+ SmallArray(SmallStorage), CurArray(SmallStorage), CurArraySize(SmallSize) {
assert(SmallSize && (SmallSize & (SmallSize-1)) == 0 &&
"Initial size must be a power of two!");
- CurArray = &SmallArray[0];
- CurArraySize = SmallSize;
- // The end pointer, always valid, is set to a valid element to help the
- // iterator.
- CurArray[SmallSize] = 0;
clear();
}
- ~SmallPtrSetImpl() {
- if (!isSmall())
- delete[] CurArray;
+ ~SmallPtrSetImplBase();
+
+public:
+ typedef unsigned size_type;
+ bool LLVM_ATTRIBUTE_UNUSED_RESULT empty() const { return size() == 0; }
+ size_type size() const { return NumElements; }
+
+ void clear() {
+ // If the capacity of the array is huge, and the # elements used is small,
+ // shrink the array.
+ if (!isSmall() && NumElements*4 < CurArraySize && CurArraySize > 32)
+ return shrink_and_clear();
+
+ // Fill the array with empty markers.
+ memset(CurArray, -1, CurArraySize*sizeof(void*));
+ NumElements = 0;
+ NumTombstones = 0;
}
-
- bool empty() const { return size() == 0; }
- unsigned size() const { return NumElements; }
-
+
+protected:
static void *getTombstoneMarker() { return reinterpret_cast<void*>(-2); }
static void *getEmptyMarker() {
// Note that -1 is chosen to make clear() efficiently implementable with
// memset and because it's not a valid pointer value.
return reinterpret_cast<void*>(-1);
}
-
- void clear() {
- // Fill the array with empty markers.
- memset(CurArray, -1, CurArraySize*sizeof(void*));
- NumElements = 0;
- NumTombstones = 0;
- }
-
- /// insert - This returns true if the pointer was new to the set, false if it
- /// was already in the set.
- bool insert(void *Ptr);
-
- /// erase - If the set contains the specified pointer, remove it and return
- /// true, otherwise return false.
- bool erase(void *Ptr);
-
- bool count(void *Ptr) const {
+
+ /// insert_imp - This returns true if the pointer was new to the set, false if
+ /// it was already in the set. This is hidden from the client so that the
+ /// derived class can check that the right type of pointer is passed in.
+ std::pair<const void *const *, bool> insert_imp(const void *Ptr);
+
+ /// erase_imp - If the set contains the specified pointer, remove it and
+ /// return true, otherwise return false. This is hidden from the client so
+ /// that the derived class can check that the right type of pointer is passed
+ /// in.
+ bool erase_imp(const void * Ptr);
+
+ bool count_imp(const void * Ptr) const {
if (isSmall()) {
// Linear search for the item.
- for (void *const *APtr = SmallArray, *const *E = SmallArray+NumElements;
- APtr != E; ++APtr)
+ for (const void *const *APtr = SmallArray,
+ *const *E = SmallArray+NumElements; APtr != E; ++APtr)
if (*APtr == Ptr)
return true;
return false;
}
-
+
// Big set case.
return *FindBucketFor(Ptr) == Ptr;
}
-
+
private:
- bool isSmall() const { return CurArray == &SmallArray[0]; }
+ bool isSmall() const { return CurArray == SmallArray; }
+
+ const void * const *FindBucketFor(const void *Ptr) const;
+ void shrink_and_clear();
- unsigned Hash(void *Ptr) const {
- return ((uintptr_t)Ptr >> 4) & (CurArraySize-1);
- }
- void * const *FindBucketFor(void *Ptr) const;
-
/// Grow - Allocate a larger backing store for the buckets and move it over.
- void Grow();
+ void Grow(unsigned NewSize);
+
+ void operator=(const SmallPtrSetImplBase &RHS) LLVM_DELETED_FUNCTION;
+protected:
+ /// swap - Swaps the elements of two sets.
+ /// Note: This method assumes that both sets have the same small size.
+ void swap(SmallPtrSetImplBase &RHS);
+
+ void CopyFrom(const SmallPtrSetImplBase &RHS);
+ void MoveFrom(unsigned SmallSize, SmallPtrSetImplBase &&RHS);
};
/// SmallPtrSetIteratorImpl - This is the common base class shared between all
/// instances of SmallPtrSetIterator.
class SmallPtrSetIteratorImpl {
protected:
- void *const *Bucket;
+ const void *const *Bucket;
+ const void *const *End;
public:
- SmallPtrSetIteratorImpl(void *const *BP) : Bucket(BP) {
- AdvanceIfNotValid();
+ explicit SmallPtrSetIteratorImpl(const void *const *BP, const void*const *E)
+ : Bucket(BP), End(E) {
+ AdvanceIfNotValid();
}
-
+
bool operator==(const SmallPtrSetIteratorImpl &RHS) const {
return Bucket == RHS.Bucket;
}
bool operator!=(const SmallPtrSetIteratorImpl &RHS) const {
return Bucket != RHS.Bucket;
}
-
+
protected:
/// AdvanceIfNotValid - If the current bucket isn't valid, advance to a bucket
/// that is. This is guaranteed to stop because the end() bucket is marked
/// valid.
void AdvanceIfNotValid() {
- while (*Bucket == SmallPtrSetImpl::getEmptyMarker() ||
- *Bucket == SmallPtrSetImpl::getTombstoneMarker())
+ assert(Bucket <= End);
+ while (Bucket != End &&
+ (*Bucket == SmallPtrSetImplBase::getEmptyMarker() ||
+ *Bucket == SmallPtrSetImplBase::getTombstoneMarker()))
++Bucket;
}
};
/// SmallPtrSetIterator - This implements a const_iterator for SmallPtrSet.
template<typename PtrTy>
class SmallPtrSetIterator : public SmallPtrSetIteratorImpl {
+ typedef PointerLikeTypeTraits<PtrTy> PtrTraits;
+
public:
- SmallPtrSetIterator(void *const *BP) : SmallPtrSetIteratorImpl(BP) {}
+ typedef PtrTy value_type;
+ typedef PtrTy reference;
+ typedef PtrTy pointer;
+ typedef std::ptrdiff_t difference_type;
+ typedef std::forward_iterator_tag iterator_category;
+
+ explicit SmallPtrSetIterator(const void *const *BP, const void *const *E)
+ : SmallPtrSetIteratorImpl(BP, E) {}
// Most methods provided by baseclass.
-
- PtrTy operator*() const {
- return static_cast<PtrTy>(*Bucket);
+
+ const PtrTy operator*() const {
+ assert(Bucket < End);
+ return PtrTraits::getFromVoidPointer(const_cast<void*>(*Bucket));
}
-
+
inline SmallPtrSetIterator& operator++() { // Preincrement
++Bucket;
AdvanceIfNotValid();
return *this;
}
-
+
SmallPtrSetIterator operator++(int) { // Postincrement
SmallPtrSetIterator tmp = *this; ++*this; return tmp;
}
};
-/// NextPowerOfTwo - This is a helper template that rounds N up to the next
-/// power of two.
+/// RoundUpToPowerOfTwo - This is a helper template that rounds N up to the next
+/// power of two (which means N itself if N is already a power of two).
template<unsigned N>
-struct NextPowerOfTwo;
+struct RoundUpToPowerOfTwo;
-/// NextPowerOfTwoH - If N is not a power of two, increase it. This is a helper
-/// template used to implement NextPowerOfTwo.
+/// RoundUpToPowerOfTwoH - If N is not a power of two, increase it. This is a
+/// helper template used to implement RoundUpToPowerOfTwo.
template<unsigned N, bool isPowerTwo>
-struct NextPowerOfTwoH {
+struct RoundUpToPowerOfTwoH {
enum { Val = N };
};
template<unsigned N>
-struct NextPowerOfTwoH<N, false> {
+struct RoundUpToPowerOfTwoH<N, false> {
enum {
// We could just use NextVal = N+1, but this converges faster. N|(N-1) sets
// the right-most zero bits to one all at once, e.g. 0b0011000 -> 0b0011111.
- Val = NextPowerOfTwo<(N|(N-1)) + 1>::Val
+ Val = RoundUpToPowerOfTwo<(N|(N-1)) + 1>::Val
};
};
template<unsigned N>
-struct NextPowerOfTwo {
- enum { Val = NextPowerOfTwoH<N, (N&(N-1)) == 0>::Val };
+struct RoundUpToPowerOfTwo {
+ enum { Val = RoundUpToPowerOfTwoH<N, (N&(N-1)) == 0>::Val };
};
+
+
+/// \brief A templated base class for \c SmallPtrSet which provides the
+/// typesafe interface that is common across all small sizes.
+///
+/// This is particularly useful for passing around between interface boundaries
+/// to avoid encoding a particular small size in the interface boundary.
+template <typename PtrType>
+class SmallPtrSetImpl : public SmallPtrSetImplBase {
+ typedef PointerLikeTypeTraits<PtrType> PtrTraits;
+
+ SmallPtrSetImpl(const SmallPtrSetImpl&) LLVM_DELETED_FUNCTION;
+protected:
+ // Constructors that forward to the base.
+ SmallPtrSetImpl(const void **SmallStorage, const SmallPtrSetImpl &that)
+ : SmallPtrSetImplBase(SmallStorage, that) {}
+ SmallPtrSetImpl(const void **SmallStorage, unsigned SmallSize,
+ SmallPtrSetImpl &&that)
+ : SmallPtrSetImplBase(SmallStorage, SmallSize, std::move(that)) {}
+ explicit SmallPtrSetImpl(const void **SmallStorage, unsigned SmallSize)
+ : SmallPtrSetImplBase(SmallStorage, SmallSize) {}
+
+public:
+ typedef SmallPtrSetIterator<PtrType> iterator;
+ typedef SmallPtrSetIterator<PtrType> const_iterator;
+
+ /// Inserts Ptr if and only if there is no element in the container equal to
+ /// Ptr. The bool component of the returned pair is true if and only if the
+ /// insertion takes place, and the iterator component of the pair points to
+ /// the element equal to Ptr.
+ std::pair<iterator, bool> insert(PtrType Ptr) {
+ auto p = insert_imp(PtrTraits::getAsVoidPointer(Ptr));
+ return std::make_pair(iterator(p.first, CurArray + CurArraySize), p.second);
+ }
+ /// erase - If the set contains the specified pointer, remove it and return
+ /// true, otherwise return false.
+ bool erase(PtrType Ptr) {
+ return erase_imp(PtrTraits::getAsVoidPointer(Ptr));
+ }
+
+ /// count - Return 1 if the specified pointer is in the set, 0 otherwise.
+ size_type count(PtrType Ptr) const {
+ return count_imp(PtrTraits::getAsVoidPointer(Ptr)) ? 1 : 0;
+ }
+
+ template <typename IterT>
+ void insert(IterT I, IterT E) {
+ for (; I != E; ++I)
+ insert(*I);
+ }
-/// SmallPtrSet - This class implements a set which is optimizer for holding
+ inline iterator begin() const {
+ return iterator(CurArray, CurArray+CurArraySize);
+ }
+ inline iterator end() const {
+ return iterator(CurArray+CurArraySize, CurArray+CurArraySize);
+ }
+};
+
+/// SmallPtrSet - This class implements a set which is optimized for holding
/// SmallSize or less elements. This internally rounds up SmallSize to the next
/// power of two if it is not already a power of two. See the comments above
-/// SmallPtrSetImpl for details of the algorithm.
+/// SmallPtrSetImplBase for details of the algorithm.
template<class PtrType, unsigned SmallSize>
-class SmallPtrSet : public SmallPtrSetImpl {
+class SmallPtrSet : public SmallPtrSetImpl<PtrType> {
+ typedef SmallPtrSetImpl<PtrType> BaseT;
+
// Make sure that SmallSize is a power of two, round up if not.
- enum { SmallSizePowTwo = NextPowerOfTwo<SmallSize>::Val };
- void *SmallArray[SmallSizePowTwo];
+ enum { SmallSizePowTwo = RoundUpToPowerOfTwo<SmallSize>::Val };
+ /// SmallStorage - Fixed size storage used in 'small mode'.
+ const void *SmallStorage[SmallSizePowTwo];
public:
- SmallPtrSet() : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) {}
-
+ SmallPtrSet() : BaseT(SmallStorage, SmallSizePowTwo) {}
+ SmallPtrSet(const SmallPtrSet &that) : BaseT(SmallStorage, that) {}
+ SmallPtrSet(SmallPtrSet &&that)
+ : BaseT(SmallStorage, SmallSizePowTwo, std::move(that)) {}
+
template<typename It>
- SmallPtrSet(It I, It E)
- : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) {
- for (; I != E; ++I)
- insert(*I);
+ SmallPtrSet(It I, It E) : BaseT(SmallStorage, SmallSizePowTwo) {
+ this->insert(I, E);
}
-
- typedef SmallPtrSetIterator<PtrType> iterator;
- typedef SmallPtrSetIterator<PtrType> const_iterator;
- inline iterator begin() const {
- return iterator(CurArray);
+
+ SmallPtrSet<PtrType, SmallSize> &
+ operator=(const SmallPtrSet<PtrType, SmallSize> &RHS) {
+ if (&RHS != this)
+ this->CopyFrom(RHS);
+ return *this;
}
- inline iterator end() const {
- return iterator(CurArray+CurArraySize);
+
+ SmallPtrSet<PtrType, SmallSize>&
+ operator=(SmallPtrSet<PtrType, SmallSize> &&RHS) {
+ if (&RHS != this)
+ this->MoveFrom(SmallSizePowTwo, std::move(RHS));
+ return *this;
+ }
+
+ /// swap - Swaps the elements of two sets.
+ void swap(SmallPtrSet<PtrType, SmallSize> &RHS) {
+ SmallPtrSetImplBase::swap(RHS);
}
};
}
+namespace std {
+ /// Implement std::swap in terms of SmallPtrSet swap.
+ template<class T, unsigned N>
+ inline void swap(llvm::SmallPtrSet<T, N> &LHS, llvm::SmallPtrSet<T, N> &RHS) {
+ LHS.swap(RHS);
+ }
+}
+
#endif
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