| //===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines the SmallVector class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_ADT_SMALLVECTOR_H |
| #define LLVM_ADT_SMALLVECTOR_H |
| |
| #include "llvm/ADT/iterator.h" |
| #include "llvm/Support/type_traits.h" |
| #include <algorithm> |
| #include <cstring> |
| #include <memory> |
| #include <cassert> |
| |
| #ifdef _MSC_VER |
| namespace std { |
| #if _MSC_VER <= 1310 |
| // Work around flawed VC++ implementation of std::uninitialized_copy. Define |
| // additional overloads so that elements with pointer types are recognized as |
| // scalars and not objects, causing bizarre type conversion errors. |
| template<class T1, class T2> |
| inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 **, T2 **) { |
| _Scalar_ptr_iterator_tag _Cat; |
| return _Cat; |
| } |
| |
| template<class T1, class T2> |
| inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const *, T2 **) { |
| _Scalar_ptr_iterator_tag _Cat; |
| return _Cat; |
| } |
| #else |
| // FIXME: It is not clear if the problem is fixed in VS 2005. What is clear |
| // is that the above hack won't work if it wasn't fixed. |
| #endif |
| } |
| #endif |
| |
| namespace llvm { |
| |
| /// SmallVectorImpl - This class consists of common code factored out of the |
| /// SmallVector class to reduce code duplication based on the SmallVector 'N' |
| /// template parameter. |
| template <typename T> |
| class SmallVectorImpl { |
| protected: |
| T *Begin, *End, *Capacity; |
| |
| // Allocate raw space for N elements of type T. If T has a ctor or dtor, we |
| // don't want it to be automatically run, so we need to represent the space as |
| // something else. An array of char would work great, but might not be |
| // aligned sufficiently. Instead, we either use GCC extensions, or some |
| // number of union instances for the space, which guarantee maximal alignment. |
| protected: |
| #ifdef __GNUC__ |
| typedef char U; |
| U FirstEl __attribute__((aligned)); |
| #else |
| union U { |
| double D; |
| long double LD; |
| long long L; |
| void *P; |
| } FirstEl; |
| #endif |
| // Space after 'FirstEl' is clobbered, do not add any instance vars after it. |
| public: |
| // Default ctor - Initialize to empty. |
| SmallVectorImpl(unsigned N) |
| : Begin(reinterpret_cast<T*>(&FirstEl)), |
| End(reinterpret_cast<T*>(&FirstEl)), |
| Capacity(reinterpret_cast<T*>(&FirstEl)+N) { |
| } |
| |
| ~SmallVectorImpl() { |
| // Destroy the constructed elements in the vector. |
| destroy_range(Begin, End); |
| |
| // If this wasn't grown from the inline copy, deallocate the old space. |
| if (!isSmall()) |
| operator delete(Begin); |
| } |
| |
| typedef size_t size_type; |
| typedef ptrdiff_t difference_type; |
| typedef T value_type; |
| typedef T* iterator; |
| typedef const T* const_iterator; |
| |
| typedef std::reverse_iterator<const_iterator> const_reverse_iterator; |
| typedef std::reverse_iterator<iterator> reverse_iterator; |
| |
| typedef T& reference; |
| typedef const T& const_reference; |
| typedef T* pointer; |
| typedef const T* const_pointer; |
| |
| bool empty() const { return Begin == End; } |
| size_type size() const { return End-Begin; } |
| size_type max_size() const { return size_type(-1) / sizeof(T); } |
| |
| // forward iterator creation methods. |
| iterator begin() { return Begin; } |
| const_iterator begin() const { return Begin; } |
| iterator end() { return End; } |
| const_iterator end() const { return End; } |
| |
| // reverse iterator creation methods. |
| reverse_iterator rbegin() { return reverse_iterator(end()); } |
| const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); } |
| reverse_iterator rend() { return reverse_iterator(begin()); } |
| const_reverse_iterator rend() const { return const_reverse_iterator(begin());} |
| |
| |
| /* These asserts could be "Begin + idx < End", but there are lots of places |
| in llvm where we use &v[v.size()] instead of v.end(). */ |
| reference operator[](unsigned idx) { |
| assert (Begin + idx <= End); |
| return Begin[idx]; |
| } |
| const_reference operator[](unsigned idx) const { |
| assert (Begin + idx <= End); |
| return Begin[idx]; |
| } |
| |
| reference front() { |
| return begin()[0]; |
| } |
| const_reference front() const { |
| return begin()[0]; |
| } |
| |
| reference back() { |
| return end()[-1]; |
| } |
| const_reference back() const { |
| return end()[-1]; |
| } |
| |
| void push_back(const_reference Elt) { |
| if (End < Capacity) { |
| Retry: |
| new (End) T(Elt); |
| ++End; |
| return; |
| } |
| grow(); |
| goto Retry; |
| } |
| |
| void pop_back() { |
| --End; |
| End->~T(); |
| } |
| |
| T pop_back_val() { |
| T Result = back(); |
| pop_back(); |
| return Result; |
| } |
| |
| void clear() { |
| destroy_range(Begin, End); |
| End = Begin; |
| } |
| |
| void resize(unsigned N) { |
| if (N < size()) { |
| destroy_range(Begin+N, End); |
| End = Begin+N; |
| } else if (N > size()) { |
| if (unsigned(Capacity-Begin) < N) |
| grow(N); |
| construct_range(End, Begin+N, T()); |
| End = Begin+N; |
| } |
| } |
| |
| void resize(unsigned N, const T &NV) { |
| if (N < size()) { |
| destroy_range(Begin+N, End); |
| End = Begin+N; |
| } else if (N > size()) { |
| if (unsigned(Capacity-Begin) < N) |
| grow(N); |
| construct_range(End, Begin+N, NV); |
| End = Begin+N; |
| } |
| } |
| |
| void reserve(unsigned N) { |
| if (unsigned(Capacity-Begin) < N) |
| grow(N); |
| } |
| |
| void swap(SmallVectorImpl &RHS); |
| |
| /// append - Add the specified range to the end of the SmallVector. |
| /// |
| template<typename in_iter> |
| void append(in_iter in_start, in_iter in_end) { |
| size_type NumInputs = std::distance(in_start, in_end); |
| // Grow allocated space if needed. |
| if (End+NumInputs > Capacity) |
| grow(size()+NumInputs); |
| |
| // Copy the new elements over. |
| std::uninitialized_copy(in_start, in_end, End); |
| End += NumInputs; |
| } |
| |
| /// append - Add the specified range to the end of the SmallVector. |
| /// |
| void append(size_type NumInputs, const T &Elt) { |
| // Grow allocated space if needed. |
| if (End+NumInputs > Capacity) |
| grow(size()+NumInputs); |
| |
| // Copy the new elements over. |
| std::uninitialized_fill_n(End, NumInputs, Elt); |
| End += NumInputs; |
| } |
| |
| void assign(unsigned NumElts, const T &Elt) { |
| clear(); |
| if (unsigned(Capacity-Begin) < NumElts) |
| grow(NumElts); |
| End = Begin+NumElts; |
| construct_range(Begin, End, Elt); |
| } |
| |
| iterator erase(iterator I) { |
| iterator N = I; |
| // Shift all elts down one. |
| std::copy(I+1, End, I); |
| // Drop the last elt. |
| pop_back(); |
| return(N); |
| } |
| |
| iterator erase(iterator S, iterator E) { |
| iterator N = S; |
| // Shift all elts down. |
| iterator I = std::copy(E, End, S); |
| // Drop the last elts. |
| destroy_range(I, End); |
| End = I; |
| return(N); |
| } |
| |
| iterator insert(iterator I, const T &Elt) { |
| if (I == End) { // Important special case for empty vector. |
| push_back(Elt); |
| return end()-1; |
| } |
| |
| if (End < Capacity) { |
| Retry: |
| new (End) T(back()); |
| ++End; |
| // Push everything else over. |
| std::copy_backward(I, End-1, End); |
| *I = Elt; |
| return I; |
| } |
| size_t EltNo = I-Begin; |
| grow(); |
| I = Begin+EltNo; |
| goto Retry; |
| } |
| |
| iterator insert(iterator I, size_type NumToInsert, const T &Elt) { |
| if (I == End) { // Important special case for empty vector. |
| append(NumToInsert, Elt); |
| return end()-1; |
| } |
| |
| // Convert iterator to elt# to avoid invalidating iterator when we reserve() |
| size_t InsertElt = I-begin(); |
| |
| // Ensure there is enough space. |
| reserve(static_cast<unsigned>(size() + NumToInsert)); |
| |
| // Uninvalidate the iterator. |
| I = begin()+InsertElt; |
| |
| // If we already have this many elements in the collection, append the |
| // dest elements at the end, then copy over the appropriate elements. Since |
| // we already reserved space, we know that this won't reallocate the vector. |
| if (size() >= NumToInsert) { |
| T *OldEnd = End; |
| append(End-NumToInsert, End); |
| |
| // Copy the existing elements that get replaced. |
| std::copy(I, OldEnd-NumToInsert, I+NumToInsert); |
| |
| std::fill_n(I, NumToInsert, Elt); |
| return I; |
| } |
| |
| // Otherwise, we're inserting more elements than exist already, and we're |
| // not inserting at the end. |
| |
| // Copy over the elements that we're about to overwrite. |
| T *OldEnd = End; |
| End += NumToInsert; |
| size_t NumOverwritten = OldEnd-I; |
| std::uninitialized_copy(I, OldEnd, End-NumOverwritten); |
| |
| // Replace the overwritten part. |
| std::fill_n(I, NumOverwritten, Elt); |
| |
| // Insert the non-overwritten middle part. |
| std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt); |
| return I; |
| } |
| |
| template<typename ItTy> |
| iterator insert(iterator I, ItTy From, ItTy To) { |
| if (I == End) { // Important special case for empty vector. |
| append(From, To); |
| return end()-1; |
| } |
| |
| size_t NumToInsert = std::distance(From, To); |
| // Convert iterator to elt# to avoid invalidating iterator when we reserve() |
| size_t InsertElt = I-begin(); |
| |
| // Ensure there is enough space. |
| reserve(static_cast<unsigned>(size() + NumToInsert)); |
| |
| // Uninvalidate the iterator. |
| I = begin()+InsertElt; |
| |
| // If we already have this many elements in the collection, append the |
| // dest elements at the end, then copy over the appropriate elements. Since |
| // we already reserved space, we know that this won't reallocate the vector. |
| if (size() >= NumToInsert) { |
| T *OldEnd = End; |
| append(End-NumToInsert, End); |
| |
| // Copy the existing elements that get replaced. |
| std::copy(I, OldEnd-NumToInsert, I+NumToInsert); |
| |
| std::copy(From, To, I); |
| return I; |
| } |
| |
| // Otherwise, we're inserting more elements than exist already, and we're |
| // not inserting at the end. |
| |
| // Copy over the elements that we're about to overwrite. |
| T *OldEnd = End; |
| End += NumToInsert; |
| size_t NumOverwritten = OldEnd-I; |
| std::uninitialized_copy(I, OldEnd, End-NumOverwritten); |
| |
| // Replace the overwritten part. |
| std::copy(From, From+NumOverwritten, I); |
| |
| // Insert the non-overwritten middle part. |
| std::uninitialized_copy(From+NumOverwritten, To, OldEnd); |
| return I; |
| } |
| |
| const SmallVectorImpl &operator=(const SmallVectorImpl &RHS); |
| |
| bool operator==(const SmallVectorImpl &RHS) const { |
| if (size() != RHS.size()) return false; |
| for (T *This = Begin, *That = RHS.Begin, *E = Begin+size(); |
| This != E; ++This, ++That) |
| if (*This != *That) |
| return false; |
| return true; |
| } |
| bool operator!=(const SmallVectorImpl &RHS) const { return !(*this == RHS); } |
| |
| bool operator<(const SmallVectorImpl &RHS) const { |
| return std::lexicographical_compare(begin(), end(), |
| RHS.begin(), RHS.end()); |
| } |
| |
| private: |
| /// isSmall - Return true if this is a smallvector which has not had dynamic |
| /// memory allocated for it. |
| bool isSmall() const { |
| return static_cast<const void*>(Begin) == |
| static_cast<const void*>(&FirstEl); |
| } |
| |
| /// grow - double the size of the allocated memory, guaranteeing space for at |
| /// least one more element or MinSize if specified. |
| void grow(size_type MinSize = 0); |
| |
| void construct_range(T *S, T *E, const T &Elt) { |
| for (; S != E; ++S) |
| new (S) T(Elt); |
| } |
| |
| void destroy_range(T *S, T *E) { |
| while (S != E) { |
| --E; |
| E->~T(); |
| } |
| } |
| }; |
| |
| // Define this out-of-line to dissuade the C++ compiler from inlining it. |
| template <typename T> |
| void SmallVectorImpl<T>::grow(size_t MinSize) { |
| size_t CurCapacity = Capacity-Begin; |
| size_t CurSize = size(); |
| size_t NewCapacity = 2*CurCapacity; |
| if (NewCapacity < MinSize) |
| NewCapacity = MinSize; |
| T *NewElts = static_cast<T*>(operator new(NewCapacity*sizeof(T))); |
| |
| // Copy the elements over. |
| if (is_class<T>::value) |
| std::uninitialized_copy(Begin, End, NewElts); |
| else |
| // Use memcpy for PODs (std::uninitialized_copy optimizes to memmove). |
| memcpy(NewElts, Begin, CurSize * sizeof(T)); |
| |
| // Destroy the original elements. |
| destroy_range(Begin, End); |
| |
| // If this wasn't grown from the inline copy, deallocate the old space. |
| if (!isSmall()) |
| operator delete(Begin); |
| |
| Begin = NewElts; |
| End = NewElts+CurSize; |
| Capacity = Begin+NewCapacity; |
| } |
| |
| template <typename T> |
| void SmallVectorImpl<T>::swap(SmallVectorImpl<T> &RHS) { |
| if (this == &RHS) return; |
| |
| // We can only avoid copying elements if neither vector is small. |
| if (!isSmall() && !RHS.isSmall()) { |
| std::swap(Begin, RHS.Begin); |
| std::swap(End, RHS.End); |
| std::swap(Capacity, RHS.Capacity); |
| return; |
| } |
| if (Begin+RHS.size() > Capacity) |
| grow(RHS.size()); |
| if (RHS.begin()+size() > RHS.Capacity) |
| RHS.grow(size()); |
| |
| // Swap the shared elements. |
| size_t NumShared = size(); |
| if (NumShared > RHS.size()) NumShared = RHS.size(); |
| for (unsigned i = 0; i != static_cast<unsigned>(NumShared); ++i) |
| std::swap(Begin[i], RHS[i]); |
| |
| // Copy over the extra elts. |
| if (size() > RHS.size()) { |
| size_t EltDiff = size() - RHS.size(); |
| std::uninitialized_copy(Begin+NumShared, End, RHS.End); |
| RHS.End += EltDiff; |
| destroy_range(Begin+NumShared, End); |
| End = Begin+NumShared; |
| } else if (RHS.size() > size()) { |
| size_t EltDiff = RHS.size() - size(); |
| std::uninitialized_copy(RHS.Begin+NumShared, RHS.End, End); |
| End += EltDiff; |
| destroy_range(RHS.Begin+NumShared, RHS.End); |
| RHS.End = RHS.Begin+NumShared; |
| } |
| } |
| |
| template <typename T> |
| const SmallVectorImpl<T> & |
| SmallVectorImpl<T>::operator=(const SmallVectorImpl<T> &RHS) { |
| // Avoid self-assignment. |
| if (this == &RHS) return *this; |
| |
| // If we already have sufficient space, assign the common elements, then |
| // destroy any excess. |
| unsigned RHSSize = unsigned(RHS.size()); |
| unsigned CurSize = unsigned(size()); |
| if (CurSize >= RHSSize) { |
| // Assign common elements. |
| iterator NewEnd; |
| if (RHSSize) |
| NewEnd = std::copy(RHS.Begin, RHS.Begin+RHSSize, Begin); |
| else |
| NewEnd = Begin; |
| |
| // Destroy excess elements. |
| destroy_range(NewEnd, End); |
| |
| // Trim. |
| End = NewEnd; |
| return *this; |
| } |
| |
| // If we have to grow to have enough elements, destroy the current elements. |
| // This allows us to avoid copying them during the grow. |
| if (unsigned(Capacity-Begin) < RHSSize) { |
| // Destroy current elements. |
| destroy_range(Begin, End); |
| End = Begin; |
| CurSize = 0; |
| grow(RHSSize); |
| } else if (CurSize) { |
| // Otherwise, use assignment for the already-constructed elements. |
| std::copy(RHS.Begin, RHS.Begin+CurSize, Begin); |
| } |
| |
| // Copy construct the new elements in place. |
| std::uninitialized_copy(RHS.Begin+CurSize, RHS.End, Begin+CurSize); |
| |
| // Set end. |
| End = Begin+RHSSize; |
| return *this; |
| } |
| |
| /// SmallVector - This is a 'vector' (really, a variable-sized array), optimized |
| /// for the case when the array is small. It contains some number of elements |
| /// in-place, which allows it to avoid heap allocation when the actual number of |
| /// elements is below that threshold. This allows normal "small" cases to be |
| /// fast without losing generality for large inputs. |
| /// |
| /// Note that this does not attempt to be exception safe. |
| /// |
| template <typename T, unsigned N> |
| class SmallVector : public SmallVectorImpl<T> { |
| /// InlineElts - These are 'N-1' elements that are stored inline in the body |
| /// of the vector. The extra '1' element is stored in SmallVectorImpl. |
| typedef typename SmallVectorImpl<T>::U U; |
| enum { |
| // MinUs - The number of U's require to cover N T's. |
| MinUs = (static_cast<unsigned int>(sizeof(T))*N + |
| static_cast<unsigned int>(sizeof(U)) - 1) / |
| static_cast<unsigned int>(sizeof(U)), |
| |
| // NumInlineEltsElts - The number of elements actually in this array. There |
| // is already one in the parent class, and we have to round up to avoid |
| // having a zero-element array. |
| NumInlineEltsElts = MinUs > 1 ? (MinUs - 1) : 1, |
| |
| // NumTsAvailable - The number of T's we actually have space for, which may |
| // be more than N due to rounding. |
| NumTsAvailable = (NumInlineEltsElts+1)*static_cast<unsigned int>(sizeof(U))/ |
| static_cast<unsigned int>(sizeof(T)) |
| }; |
| U InlineElts[NumInlineEltsElts]; |
| public: |
| SmallVector() : SmallVectorImpl<T>(NumTsAvailable) { |
| } |
| |
| explicit SmallVector(unsigned Size, const T &Value = T()) |
| : SmallVectorImpl<T>(NumTsAvailable) { |
| this->reserve(Size); |
| while (Size--) |
| this->push_back(Value); |
| } |
| |
| template<typename ItTy> |
| SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(NumTsAvailable) { |
| this->append(S, E); |
| } |
| |
| SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(NumTsAvailable) { |
| if (!RHS.empty()) |
| SmallVectorImpl<T>::operator=(RHS); |
| } |
| |
| const SmallVector &operator=(const SmallVector &RHS) { |
| SmallVectorImpl<T>::operator=(RHS); |
| return *this; |
| } |
| |
| }; |
| |
| } // End llvm namespace |
| |
| namespace std { |
| /// Implement std::swap in terms of SmallVector swap. |
| template<typename T> |
| inline void |
| swap(llvm::SmallVectorImpl<T> &LHS, llvm::SmallVectorImpl<T> &RHS) { |
| LHS.swap(RHS); |
| } |
| |
| /// Implement std::swap in terms of SmallVector swap. |
| template<typename T, unsigned N> |
| inline void |
| swap(llvm::SmallVector<T, N> &LHS, llvm::SmallVector<T, N> &RHS) { |
| LHS.swap(RHS); |
| } |
| } |
| |
| #endif |