//
// 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.
//
//===----------------------------------------------------------------------===//
//
#include <cassert>
#include <cstring>
-#include "llvm/Support/DataTypes.h"
+#include <iterator>
+#include "llvm/System/DataTypes.h"
+#include "llvm/Support/PointerLikeTypeTraits.h"
namespace llvm {
+class SmallPtrSetIteratorImpl;
+
/// SmallPtrSetImpl - 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.
/// more. When this happens, the table is doubled in size.
///
class SmallPtrSetImpl {
+ 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
unsigned NumElements;
unsigned NumTombstones;
- void *SmallArray[1]; // Must be last ivar.
// Helper to copy construct a SmallPtrSet.
- SmallPtrSetImpl(const SmallPtrSetImpl& that);
-public:
- SmallPtrSetImpl(unsigned SmallSize) {
+ SmallPtrSetImpl(const void **SmallStorage, const SmallPtrSetImpl& that);
+ explicit SmallPtrSetImpl(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();
-
+
+public:
bool empty() const { return size() == 0; }
unsigned size() const { return NumElements; }
-
- 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() {
+ // 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;
}
-
- /// insert - This returns true if the pointer was new to the set, false if it
- /// was already in the set.
- bool insert(void *Ptr);
-
- template <typename IterT>
- void insert(IterT I, IterT E) {
- for (; I != E; ++I)
- insert((void*)*I);
+
+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);
}
-
- /// 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.
+ 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; }
- unsigned Hash(void *Ptr) const {
- return ((uintptr_t)Ptr >> 4) & (CurArraySize-1);
+ unsigned Hash(const void *Ptr) const {
+ return static_cast<unsigned>(((uintptr_t)Ptr >> 4) & (CurArraySize-1));
}
- void * const *FindBucketFor(void *Ptr) const;
-
+ const void * const *FindBucketFor(const void *Ptr) const;
+ void shrink_and_clear();
+
/// Grow - Allocate a larger backing store for the buckets and move it over.
void Grow();
-
+
void operator=(const SmallPtrSetImpl &RHS); // DO NOT IMPLEMENT.
protected:
void CopyFrom(const SmallPtrSetImpl &RHS);
/// instances of SmallPtrSetIterator.
class SmallPtrSetIteratorImpl {
protected:
- void *const *Bucket;
+ const void *const *Bucket;
public:
- SmallPtrSetIteratorImpl(void *const *BP) : Bucket(BP) {
+ explicit SmallPtrSetIteratorImpl(const void *const *BP) : Bucket(BP) {
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
/// 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)
+ : SmallPtrSetIteratorImpl(BP) {}
// Most methods provided by baseclass.
-
- PtrTy operator*() const {
- return static_cast<PtrTy>(*Bucket);
+
+ const PtrTy operator*() const {
+ 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;
}
struct NextPowerOfTwo {
enum { Val = NextPowerOfTwoH<N, (N&(N-1)) == 0>::Val };
};
+
-
-/// SmallPtrSet - This class implements a set which is optimizer for holding
+/// 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.
class SmallPtrSet : public SmallPtrSetImpl {
// Make sure that SmallSize is a power of two, round up if not.
enum { SmallSizePowTwo = NextPowerOfTwo<SmallSize>::Val };
- void *SmallArray[SmallSizePowTwo];
+ /// SmallStorage - Fixed size storage used in 'small mode'. The extra element
+ /// ensures that the end iterator actually points to valid memory.
+ const void *SmallStorage[SmallSizePowTwo+1];
+ typedef PointerLikeTypeTraits<PtrType> PtrTraits;
public:
- SmallPtrSet() : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) {}
- SmallPtrSet(const SmallPtrSet &that) : SmallPtrSetImpl(that) {}
-
+ SmallPtrSet() : SmallPtrSetImpl(SmallStorage, SmallSizePowTwo) {}
+ SmallPtrSet(const SmallPtrSet &that) : SmallPtrSetImpl(SmallStorage, that) {}
+
template<typename It>
- SmallPtrSet(It I, It E)
- : SmallPtrSetImpl(NextPowerOfTwo<SmallSizePowTwo>::Val) {
+ SmallPtrSet(It I, It E) : SmallPtrSetImpl(SmallStorage, SmallSizePowTwo) {
insert(I, E);
}
-
+
+ /// insert - This returns true if the pointer was new to the set, false if it
+ /// was already in the set.
+ bool insert(PtrType Ptr) {
+ return insert_imp(PtrTraits::getAsVoidPointer(Ptr));
+ }
+
+ /// 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 true if the specified pointer is in the set.
+ bool count(PtrType Ptr) const {
+ return count_imp(PtrTraits::getAsVoidPointer(Ptr));
+ }
+
+ template <typename IterT>
+ void insert(IterT I, IterT E) {
+ for (; I != E; ++I)
+ insert(*I);
+ }
+
typedef SmallPtrSetIterator<PtrType> iterator;
typedef SmallPtrSetIterator<PtrType> const_iterator;
inline iterator begin() const {
inline iterator end() const {
return iterator(CurArray+CurArraySize);
}
-
+
// Allow assignment from any smallptrset with the same element type even if it
// doesn't have the same smallsize.
const SmallPtrSet<PtrType, SmallSize>&
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