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diff --git a/ProjectBrussel/Common/SmallVector.hpp b/ProjectBrussel/Common/SmallVector.hpp new file mode 100644 index 0000000..e33a25d --- /dev/null +++ b/ProjectBrussel/Common/SmallVector.hpp @@ -0,0 +1,1332 @@ +// Obtained from https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/ADT/SmallVector.h +// commit 4b82bb6d82f65f98f23d0e4c2cd5297dc162864c +// adapted in code style and utilities to fix this project + +//===- llvm/ADT/SmallVector.h - 'Normally small' vectors --------*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// This file defines the SmallVector class. +/// +//===----------------------------------------------------------------------===// + +#pragma once + +#include <algorithm> +#include <cassert> +#include <cstddef> +#include <cstdlib> +#include <cstring> +#include <functional> +#include <initializer_list> +#include <iterator> +#include <limits> +#include <memory> +#include <new> +#include <type_traits> +#include <utility> + +#ifdef _MSC_VER +# pragma warning(push) +# pragma warning(disable : 4267) // The compiler detected a conversion from size_t to a smaller type. +#endif + +#if __has_builtin(__builtin_expect) || defined(__GNUC__) +# define LLVM_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) +# define LLVM_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) +#else +# define LLVM_LIKELY(EXPR) (EXPR) +# define LLVM_UNLIKELY(EXPR) (EXPR) +#endif + +template <typename IteratorT> +class iterator_range; + +/// This is all the stuff common to all SmallVectors. +/// +/// The template parameter specifies the type which should be used to hold the +/// Size and Capacity of the SmallVector, so it can be adjusted. +/// Using 32 bit size is desirable to shrink the size of the SmallVector. +/// Using 64 bit size is desirable for cases like SmallVector<char>, where a +/// 32 bit size would limit the vector to ~4GB. SmallVectors are used for +/// buffering bitcode output - which can exceed 4GB. +template <class Size_T> +class SmallVectorBase { +protected: + void* BeginX; + Size_T Size = 0, Capacity; + + /// The maximum value of the Size_T used. + static constexpr size_t SizeTypeMax() { + return std::numeric_limits<Size_T>::max(); + } + + SmallVectorBase() = delete; + SmallVectorBase(void* FirstEl, size_t TotalCapacity) + : BeginX(FirstEl), Capacity(TotalCapacity) {} + + /// This is a helper for \a grow() that's out of line to reduce code + /// duplication. This function will report a fatal error if it can't grow at + /// least to \p MinSize. + void* mallocForGrow(size_t MinSize, size_t TSize, size_t& NewCapacity); + + /// This is an implementation of the grow() method which only works + /// on POD-like data types and is out of line to reduce code duplication. + /// This function will report a fatal error if it cannot increase capacity. + void grow_pod(void* FirstEl, size_t MinSize, size_t TSize); + +public: + size_t size() const { return Size; } + size_t capacity() const { return Capacity; } + + [[nodiscard]] bool empty() const { return !Size; } + +protected: + /// Set the array size to \p N, which the current array must have enough + /// capacity for. + /// + /// This does not construct or destroy any elements in the vector. + void set_size(size_t N) { + assert(N <= capacity()); + Size = N; + } +}; + +template <class T> +using SmallVectorSizeType = + typename std::conditional<sizeof(T) < 4 && sizeof(void*) >= 8, uint64_t, uint32_t>::type; + +/// Figure out the offset of the first element. +template <class T, typename = void> +struct SmallVectorAlignmentAndSize { + alignas(SmallVectorBase<SmallVectorSizeType<T>>) char Base[sizeof( + SmallVectorBase<SmallVectorSizeType<T>>)]; + alignas(T) char FirstEl[sizeof(T)]; +}; + +/// This is the part of SmallVectorTemplateBase which does not depend on whether +/// the type T is a POD. The extra dummy template argument is used by ArrayRef +/// to avoid unnecessarily requiring T to be complete. +template <typename T, typename = void> +class SmallVectorTemplateCommon + : public SmallVectorBase<SmallVectorSizeType<T>> { + using Base = SmallVectorBase<SmallVectorSizeType<T>>; + + /// Find the address of the first element. For this pointer math to be valid + /// with small-size of 0 for T with lots of alignment, it's important that + /// SmallVectorStorage is properly-aligned even for small-size of 0. + void* getFirstEl() const { + return const_cast<void*>(reinterpret_cast<const void*>( + reinterpret_cast<const char*>(this) + + offsetof(SmallVectorAlignmentAndSize<T>, FirstEl))); + } + // Space after 'FirstEl' is clobbered, do not add any instance vars after it. + +protected: + SmallVectorTemplateCommon(size_t Size) + : Base(getFirstEl(), Size) {} + + void grow_pod(size_t MinSize, size_t TSize) { + Base::grow_pod(getFirstEl(), MinSize, TSize); + } + + /// Return true if this is a smallvector which has not had dynamic + /// memory allocated for it. + bool isSmall() const { return this->BeginX == getFirstEl(); } + + /// Put this vector in a state of being small. + void resetToSmall() { + this->BeginX = getFirstEl(); + this->Size = this->Capacity = 0; // FIXME: Setting Capacity to 0 is suspect. + } + + /// Return true if V is an internal reference to the given range. + bool isReferenceToRange(const void* V, const void* First, const void* Last) const { + // Use std::less to avoid UB. + std::less<> LessThan; + return !LessThan(V, First) && LessThan(V, Last); + } + + /// Return true if V is an internal reference to this vector. + bool isReferenceToStorage(const void* V) const { + return isReferenceToRange(V, this->begin(), this->end()); + } + + /// Return true if First and Last form a valid (possibly empty) range in this + /// vector's storage. + bool isRangeInStorage(const void* First, const void* Last) const { + // Use std::less to avoid UB. + std::less<> LessThan; + return !LessThan(First, this->begin()) && !LessThan(Last, First) && + !LessThan(this->end(), Last); + } + + /// Return true unless Elt will be invalidated by resizing the vector to + /// NewSize. + bool isSafeToReferenceAfterResize(const void* Elt, size_t NewSize) { + // Past the end. + if (LLVM_LIKELY(!isReferenceToStorage(Elt))) + return true; + + // Return false if Elt will be destroyed by shrinking. + if (NewSize <= this->size()) + return Elt < this->begin() + NewSize; + + // Return false if we need to grow. + return NewSize <= this->capacity(); + } + + /// Check whether Elt will be invalidated by resizing the vector to NewSize. + void assertSafeToReferenceAfterResize(const void* Elt, size_t NewSize) { + assert(isSafeToReferenceAfterResize(Elt, NewSize) && + "Attempting to reference an element of the vector in an operation " + "that invalidates it"); + } + + /// Check whether Elt will be invalidated by increasing the size of the + /// vector by N. + void assertSafeToAdd(const void* Elt, size_t N = 1) { + this->assertSafeToReferenceAfterResize(Elt, this->size() + N); + } + + /// Check whether any part of the range will be invalidated by clearing. + void assertSafeToReferenceAfterClear(const T* From, const T* To) { + if (From == To) + return; + this->assertSafeToReferenceAfterResize(From, 0); + this->assertSafeToReferenceAfterResize(To - 1, 0); + } + template < + class ItTy, + std::enable_if_t<!std::is_same<std::remove_const_t<ItTy>, T*>::value, + bool> = false> + void assertSafeToReferenceAfterClear(ItTy, ItTy) {} + + /// Check whether any part of the range will be invalidated by growing. + void assertSafeToAddRange(const T* From, const T* To) { + if (From == To) + return; + this->assertSafeToAdd(From, To - From); + this->assertSafeToAdd(To - 1, To - From); + } + template < + class ItTy, + std::enable_if_t<!std::is_same<std::remove_const_t<ItTy>, T*>::value, + bool> = false> + void assertSafeToAddRange(ItTy, ItTy) {} + + /// Reserve enough space to add one element, and return the updated element + /// pointer in case it was a reference to the storage. + template <class U> + static const T* reserveForParamAndGetAddressImpl(U* This, const T& Elt, size_t N) { + size_t NewSize = This->size() + N; + if (LLVM_LIKELY(NewSize <= This->capacity())) + return &Elt; + + bool ReferencesStorage = false; + int64_t Index = -1; + if (!U::TakesParamByValue) { + if (LLVM_UNLIKELY(This->isReferenceToStorage(&Elt))) { + ReferencesStorage = true; + Index = &Elt - This->begin(); + } + } + This->grow(NewSize); + return ReferencesStorage ? This->begin() + Index : &Elt; + } + +public: + using size_type = size_t; + using difference_type = ptrdiff_t; + using value_type = T; + using iterator = T*; + using const_iterator = const T*; + + using const_reverse_iterator = std::reverse_iterator<const_iterator>; + using reverse_iterator = std::reverse_iterator<iterator>; + + using reference = T&; + using const_reference = const T&; + using pointer = T*; + using const_pointer = const T*; + + using Base::capacity; + using Base::empty; + using Base::size; + + // forward iterator creation methods. + iterator begin() { return (iterator)this->BeginX; } + const_iterator begin() const { return (const_iterator)this->BeginX; } + iterator end() { return begin() + size(); } + const_iterator end() const { return begin() + size(); } + + // 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()); } + + size_type size_in_bytes() const { return size() * sizeof(T); } + size_type max_size() const { + return std::min(this->SizeTypeMax(), size_type(-1) / sizeof(T)); + } + + size_t capacity_in_bytes() const { return capacity() * sizeof(T); } + + /// Return a pointer to the vector's buffer, even if empty(). + pointer data() { return pointer(begin()); } + /// Return a pointer to the vector's buffer, even if empty(). + const_pointer data() const { return const_pointer(begin()); } + + reference operator[](size_type idx) { + assert(idx < size()); + return begin()[idx]; + } + const_reference operator[](size_type idx) const { + assert(idx < size()); + return begin()[idx]; + } + + reference front() { + assert(!empty()); + return begin()[0]; + } + const_reference front() const { + assert(!empty()); + return begin()[0]; + } + + reference back() { + assert(!empty()); + return end()[-1]; + } + const_reference back() const { + assert(!empty()); + return end()[-1]; + } +}; + +/// SmallVectorTemplateBase<TriviallyCopyable = false> - This is where we put +/// method implementations that are designed to work with non-trivial T's. +/// +/// We approximate is_trivially_copyable with trivial move/copy construction and +/// trivial destruction. While the standard doesn't specify that you're allowed +/// copy these types with memcpy, there is no way for the type to observe this. +/// This catches the important case of std::pair<POD, POD>, which is not +/// trivially assignable. +template <typename T, bool = (std::is_trivially_copy_constructible<T>::value) && (std::is_trivially_move_constructible<T>::value) && std::is_trivially_destructible<T>::value> +class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> { + friend class SmallVectorTemplateCommon<T>; + +protected: + static constexpr bool TakesParamByValue = false; + using ValueParamT = const T&; + + SmallVectorTemplateBase(size_t Size) + : SmallVectorTemplateCommon<T>(Size) {} + + static void destroy_range(T* S, T* E) { + while (S != E) { + --E; + E->~T(); + } + } + + /// Move the range [I, E) into the uninitialized memory starting with "Dest", + /// constructing elements as needed. + template <typename It1, typename It2> + static void uninitialized_move(It1 I, It1 E, It2 Dest) { + std::uninitialized_copy(std::make_move_iterator(I), + std::make_move_iterator(E), + Dest); + } + + /// Copy the range [I, E) onto the uninitialized memory starting with "Dest", + /// constructing elements as needed. + template <typename It1, typename It2> + static void uninitialized_copy(It1 I, It1 E, It2 Dest) { + std::uninitialized_copy(I, E, Dest); + } + + /// Grow the allocated memory (without initializing new elements), doubling + /// the size of the allocated memory. Guarantees space for at least one more + /// element, or MinSize more elements if specified. + void grow(size_t MinSize = 0); + + /// Create a new allocation big enough for \p MinSize and pass back its size + /// in \p NewCapacity. This is the first section of \a grow(). + T* mallocForGrow(size_t MinSize, size_t& NewCapacity) { + return static_cast<T*>( + SmallVectorBase<SmallVectorSizeType<T>>::mallocForGrow( + MinSize, sizeof(T), NewCapacity)); + } + + /// Move existing elements over to the new allocation \p NewElts, the middle + /// section of \a grow(). + void moveElementsForGrow(T* NewElts); + + /// Transfer ownership of the allocation, finishing up \a grow(). + void takeAllocationForGrow(T* NewElts, size_t NewCapacity); + + /// Reserve enough space to add one element, and return the updated element + /// pointer in case it was a reference to the storage. + const T* reserveForParamAndGetAddress(const T& Elt, size_t N = 1) { + return this->reserveForParamAndGetAddressImpl(this, Elt, N); + } + + /// Reserve enough space to add one element, and return the updated element + /// pointer in case it was a reference to the storage. + T* reserveForParamAndGetAddress(T& Elt, size_t N = 1) { + return const_cast<T*>( + this->reserveForParamAndGetAddressImpl(this, Elt, N)); + } + + static T&& forward_value_param(T&& V) { return std::move(V); } + static const T& forward_value_param(const T& V) { return V; } + + void growAndAssign(size_t NumElts, const T& Elt) { + // Grow manually in case Elt is an internal reference. + size_t NewCapacity; + T* NewElts = mallocForGrow(NumElts, NewCapacity); + std::uninitialized_fill_n(NewElts, NumElts, Elt); + this->destroy_range(this->begin(), this->end()); + takeAllocationForGrow(NewElts, NewCapacity); + this->set_size(NumElts); + } + + template <typename... ArgTypes> + T& growAndEmplaceBack(ArgTypes&&... Args) { + // Grow manually in case one of Args is an internal reference. + size_t NewCapacity; + T* NewElts = mallocForGrow(0, NewCapacity); + ::new ((void*)(NewElts + this->size())) T(std::forward<ArgTypes>(Args)...); + moveElementsForGrow(NewElts); + takeAllocationForGrow(NewElts, NewCapacity); + this->set_size(this->size() + 1); + return this->back(); + } + +public: + void push_back(const T& Elt) { + const T* EltPtr = reserveForParamAndGetAddress(Elt); + ::new ((void*)this->end()) T(*EltPtr); + this->set_size(this->size() + 1); + } + + void push_back(T&& Elt) { + T* EltPtr = reserveForParamAndGetAddress(Elt); + ::new ((void*)this->end()) T(::std::move(*EltPtr)); + this->set_size(this->size() + 1); + } + + void pop_back() { + this->set_size(this->size() - 1); + this->end()->~T(); + } +}; + +// Define this out-of-line to dissuade the C++ compiler from inlining it. +template <typename T, bool TriviallyCopyable> +void SmallVectorTemplateBase<T, TriviallyCopyable>::grow(size_t MinSize) { + size_t NewCapacity; + T* NewElts = mallocForGrow(MinSize, NewCapacity); + moveElementsForGrow(NewElts); + takeAllocationForGrow(NewElts, NewCapacity); +} + +// Define this out-of-line to dissuade the C++ compiler from inlining it. +template <typename T, bool TriviallyCopyable> +void SmallVectorTemplateBase<T, TriviallyCopyable>::moveElementsForGrow( + T* NewElts) { + // Move the elements over. + this->uninitialized_move(this->begin(), this->end(), NewElts); + + // Destroy the original elements. + destroy_range(this->begin(), this->end()); +} + +// Define this out-of-line to dissuade the C++ compiler from inlining it. +template <typename T, bool TriviallyCopyable> +void SmallVectorTemplateBase<T, TriviallyCopyable>::takeAllocationForGrow( + T* NewElts, size_t NewCapacity) { + // If this wasn't grown from the inline copy, deallocate the old space. + if (!this->isSmall()) + free(this->begin()); + + this->BeginX = NewElts; + this->Capacity = NewCapacity; +} + +/// SmallVectorTemplateBase<TriviallyCopyable = true> - This is where we put +/// method implementations that are designed to work with trivially copyable +/// T's. This allows using memcpy in place of copy/move construction and +/// skipping destruction. +template <typename T> +class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> { + friend class SmallVectorTemplateCommon<T>; + +protected: + /// True if it's cheap enough to take parameters by value. Doing so avoids + /// overhead related to mitigations for reference invalidation. + static constexpr bool TakesParamByValue = sizeof(T) <= 2 * sizeof(void*); + + /// Either const T& or T, depending on whether it's cheap enough to take + /// parameters by value. + using ValueParamT = + typename std::conditional<TakesParamByValue, T, const T&>::type; + + SmallVectorTemplateBase(size_t Size) + : SmallVectorTemplateCommon<T>(Size) {} + + // No need to do a destroy loop for POD's. + static void destroy_range(T*, T*) {} + + /// Move the range [I, E) onto the uninitialized memory + /// starting with "Dest", constructing elements into it as needed. + template <typename It1, typename It2> + static void uninitialized_move(It1 I, It1 E, It2 Dest) { + // Just do a copy. + uninitialized_copy(I, E, Dest); + } + + /// Copy the range [I, E) onto the uninitialized memory + /// starting with "Dest", constructing elements into it as needed. + template <typename It1, typename It2> + static void uninitialized_copy(It1 I, It1 E, It2 Dest) { + // Arbitrary iterator types; just use the basic implementation. + std::uninitialized_copy(I, E, Dest); + } + + /// Copy the range [I, E) onto the uninitialized memory + /// starting with "Dest", constructing elements into it as needed. + template <typename T1, typename T2> + static void uninitialized_copy( + T1* I, T1* E, T2* Dest, std::enable_if_t<std::is_same<typename std::remove_const<T1>::type, T2>::value>* = nullptr) { + // Use memcpy for PODs iterated by pointers (which includes SmallVector + // iterators): std::uninitialized_copy optimizes to memmove, but we can + // use memcpy here. Note that I and E are iterators and thus might be + // invalid for memcpy if they are equal. + if (I != E) + memcpy(reinterpret_cast<void*>(Dest), I, (E - I) * sizeof(T)); + } + + /// Double the size of the allocated memory, guaranteeing space for at + /// least one more element or MinSize if specified. + void grow(size_t MinSize = 0) { this->grow_pod(MinSize, sizeof(T)); } + + /// Reserve enough space to add one element, and return the updated element + /// pointer in case it was a reference to the storage. + const T* reserveForParamAndGetAddress(const T& Elt, size_t N = 1) { + return this->reserveForParamAndGetAddressImpl(this, Elt, N); + } + + /// Reserve enough space to add one element, and return the updated element + /// pointer in case it was a reference to the storage. + T* reserveForParamAndGetAddress(T& Elt, size_t N = 1) { + return const_cast<T*>( + this->reserveForParamAndGetAddressImpl(this, Elt, N)); + } + + /// Copy \p V or return a reference, depending on \a ValueParamT. + static ValueParamT forward_value_param(ValueParamT V) { return V; } + + void growAndAssign(size_t NumElts, T Elt) { + // Elt has been copied in case it's an internal reference, side-stepping + // reference invalidation problems without losing the realloc optimization. + this->set_size(0); + this->grow(NumElts); + std::uninitialized_fill_n(this->begin(), NumElts, Elt); + this->set_size(NumElts); + } + + template <typename... ArgTypes> + T& growAndEmplaceBack(ArgTypes&&... Args) { + // Use push_back with a copy in case Args has an internal reference, + // side-stepping reference invalidation problems without losing the realloc + // optimization. + push_back(T(std::forward<ArgTypes>(Args)...)); + return this->back(); + } + +public: + void push_back(ValueParamT Elt) { + const T* EltPtr = reserveForParamAndGetAddress(Elt); + memcpy(reinterpret_cast<void*>(this->end()), EltPtr, sizeof(T)); + this->set_size(this->size() + 1); + } + + void pop_back() { this->set_size(this->size() - 1); } +}; + +/// 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 : public SmallVectorTemplateBase<T> { + using SuperClass = SmallVectorTemplateBase<T>; + +public: + using iterator = typename SuperClass::iterator; + using const_iterator = typename SuperClass::const_iterator; + using reference = typename SuperClass::reference; + using size_type = typename SuperClass::size_type; + +protected: + using SmallVectorTemplateBase<T>::TakesParamByValue; + using ValueParamT = typename SuperClass::ValueParamT; + + // Default ctor - Initialize to empty. + explicit SmallVectorImpl(unsigned N) + : SmallVectorTemplateBase<T>(N) {} + + void assignRemote(SmallVectorImpl&& RHS) { + this->destroy_range(this->begin(), this->end()); + if (!this->isSmall()) + free(this->begin()); + this->BeginX = RHS.BeginX; + this->Size = RHS.Size; + this->Capacity = RHS.Capacity; + RHS.resetToSmall(); + } + +public: + SmallVectorImpl(const SmallVectorImpl&) = delete; + + ~SmallVectorImpl() { + // Subclass has already destructed this vector's elements. + // If this wasn't grown from the inline copy, deallocate the old space. + if (!this->isSmall()) + free(this->begin()); + } + + void clear() { + this->destroy_range(this->begin(), this->end()); + this->Size = 0; + } + +private: + // Make set_size() private to avoid misuse in subclasses. + using SuperClass::set_size; + + template <bool ForOverwrite> + void resizeImpl(size_type N) { + if (N == this->size()) + return; + + if (N < this->size()) { + this->truncate(N); + return; + } + + this->reserve(N); + for (auto I = this->end(), E = this->begin() + N; I != E; ++I) + if (ForOverwrite) + new (&*I) T; + else + new (&*I) T(); + this->set_size(N); + } + +public: + void resize(size_type N) { resizeImpl<false>(N); } + + /// Like resize, but \ref T is POD, the new values won't be initialized. + void resize_for_overwrite(size_type N) { resizeImpl<true>(N); } + + /// Like resize, but requires that \p N is less than \a size(). + void truncate(size_type N) { + assert(this->size() >= N && "Cannot increase size with truncate"); + this->destroy_range(this->begin() + N, this->end()); + this->set_size(N); + } + + void resize(size_type N, ValueParamT NV) { + if (N == this->size()) + return; + + if (N < this->size()) { + this->truncate(N); + return; + } + + // N > this->size(). Defer to append. + this->append(N - this->size(), NV); + } + + void reserve(size_type N) { + if (this->capacity() < N) + this->grow(N); + } + + void pop_back_n(size_type NumItems) { + assert(this->size() >= NumItems); + truncate(this->size() - NumItems); + } + + [[nodiscard]] T pop_back_val() { + T Result = ::std::move(this->back()); + this->pop_back(); + return Result; + } + + void swap(SmallVectorImpl& RHS); + + /// Add the specified range to the end of the SmallVector. + template <typename in_iter, + typename = std::enable_if_t<std::is_convertible< + typename std::iterator_traits<in_iter>::iterator_category, + std::input_iterator_tag>::value>> + void append(in_iter in_start, in_iter in_end) { + this->assertSafeToAddRange(in_start, in_end); + size_type NumInputs = std::distance(in_start, in_end); + this->reserve(this->size() + NumInputs); + this->uninitialized_copy(in_start, in_end, this->end()); + this->set_size(this->size() + NumInputs); + } + + /// Append \p NumInputs copies of \p Elt to the end. + void append(size_type NumInputs, ValueParamT Elt) { + const T* EltPtr = this->reserveForParamAndGetAddress(Elt, NumInputs); + std::uninitialized_fill_n(this->end(), NumInputs, *EltPtr); + this->set_size(this->size() + NumInputs); + } + + void append(std::initializer_list<T> IL) { + append(IL.begin(), IL.end()); + } + + void append(const SmallVectorImpl& RHS) { append(RHS.begin(), RHS.end()); } + + void assign(size_type NumElts, ValueParamT Elt) { + // Note that Elt could be an internal reference. + if (NumElts > this->capacity()) { + this->growAndAssign(NumElts, Elt); + return; + } + + // Assign over existing elements. + std::fill_n(this->begin(), std::min(NumElts, this->size()), Elt); + if (NumElts > this->size()) + std::uninitialized_fill_n(this->end(), NumElts - this->size(), Elt); + else if (NumElts < this->size()) + this->destroy_range(this->begin() + NumElts, this->end()); + this->set_size(NumElts); + } + + // FIXME: Consider assigning over existing elements, rather than clearing & + // re-initializing them - for all assign(...) variants. + + template <typename in_iter, + typename = std::enable_if_t<std::is_convertible< + typename std::iterator_traits<in_iter>::iterator_category, + std::input_iterator_tag>::value>> + void assign(in_iter in_start, in_iter in_end) { + this->assertSafeToReferenceAfterClear(in_start, in_end); + clear(); + append(in_start, in_end); + } + + void assign(std::initializer_list<T> IL) { + clear(); + append(IL); + } + + void assign(const SmallVectorImpl& RHS) { assign(RHS.begin(), RHS.end()); } + + iterator erase(const_iterator CI) { + // Just cast away constness because this is a non-const member function. + iterator I = const_cast<iterator>(CI); + + assert(this->isReferenceToStorage(CI) && "Iterator to erase is out of bounds."); + + iterator N = I; + // Shift all elts down one. + std::move(I + 1, this->end(), I); + // Drop the last elt. + this->pop_back(); + return (N); + } + + iterator erase(const_iterator CS, const_iterator CE) { + // Just cast away constness because this is a non-const member function. + iterator S = const_cast<iterator>(CS); + iterator E = const_cast<iterator>(CE); + + assert(this->isRangeInStorage(S, E) && "Range to erase is out of bounds."); + + iterator N = S; + // Shift all elts down. + iterator I = std::move(E, this->end(), S); + // Drop the last elts. + this->destroy_range(I, this->end()); + this->set_size(I - this->begin()); + return (N); + } + +private: + template <class ArgType> + iterator insert_one_impl(iterator I, ArgType&& Elt) { + // Callers ensure that ArgType is derived from T. + static_assert( + std::is_same<std::remove_const_t<std::remove_reference_t<ArgType>>, + T>::value, + "ArgType must be derived from T!"); + + if (I == this->end()) { // Important special case for empty vector. + this->push_back(::std::forward<ArgType>(Elt)); + return this->end() - 1; + } + + assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds."); + + // Grow if necessary. + size_t Index = I - this->begin(); + std::remove_reference_t<ArgType>* EltPtr = + this->reserveForParamAndGetAddress(Elt); + I = this->begin() + Index; + + ::new ((void*)this->end()) T(::std::move(this->back())); + // Push everything else over. + std::move_backward(I, this->end() - 1, this->end()); + this->set_size(this->size() + 1); + + // If we just moved the element we're inserting, be sure to update + // the reference (never happens if TakesParamByValue). + static_assert(!TakesParamByValue || std::is_same<ArgType, T>::value, + "ArgType must be 'T' when taking by value!"); + if (!TakesParamByValue && this->isReferenceToRange(EltPtr, I, this->end())) + ++EltPtr; + + *I = ::std::forward<ArgType>(*EltPtr); + return I; + } + +public: + iterator insert(iterator I, T&& Elt) { + return insert_one_impl(I, this->forward_value_param(std::move(Elt))); + } + + iterator insert(iterator I, const T& Elt) { + return insert_one_impl(I, this->forward_value_param(Elt)); + } + + iterator insert(iterator I, size_type NumToInsert, ValueParamT Elt) { + // Convert iterator to elt# to avoid invalidating iterator when we reserve() + size_t InsertElt = I - this->begin(); + + if (I == this->end()) { // Important special case for empty vector. + append(NumToInsert, Elt); + return this->begin() + InsertElt; + } + + assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds."); + + // Ensure there is enough space, and get the (maybe updated) address of + // Elt. + const T* EltPtr = this->reserveForParamAndGetAddress(Elt, NumToInsert); + + // Uninvalidate the iterator. + I = this->begin() + InsertElt; + + // If there are more elements between the insertion point and the end of the + // range than there are being inserted, we can use a simple approach to + // insertion. Since we already reserved space, we know that this won't + // reallocate the vector. + if (size_t(this->end() - I) >= NumToInsert) { + T* OldEnd = this->end(); + append(std::move_iterator<iterator>(this->end() - NumToInsert), + std::move_iterator<iterator>(this->end())); + + // Copy the existing elements that get replaced. + std::move_backward(I, OldEnd - NumToInsert, OldEnd); + + // If we just moved the element we're inserting, be sure to update + // the reference (never happens if TakesParamByValue). + if (!TakesParamByValue && I <= EltPtr && EltPtr < this->end()) + EltPtr += NumToInsert; + + std::fill_n(I, NumToInsert, *EltPtr); + return I; + } + + // Otherwise, we're inserting more elements than exist already, and we're + // not inserting at the end. + + // Move over the elements that we're about to overwrite. + T* OldEnd = this->end(); + this->set_size(this->size() + NumToInsert); + size_t NumOverwritten = OldEnd - I; + this->uninitialized_move(I, OldEnd, this->end() - NumOverwritten); + + // If we just moved the element we're inserting, be sure to update + // the reference (never happens if TakesParamByValue). + if (!TakesParamByValue && I <= EltPtr && EltPtr < this->end()) + EltPtr += NumToInsert; + + // Replace the overwritten part. + std::fill_n(I, NumOverwritten, *EltPtr); + + // Insert the non-overwritten middle part. + std::uninitialized_fill_n(OldEnd, NumToInsert - NumOverwritten, *EltPtr); + return I; + } + + template <typename ItTy, + typename = std::enable_if_t<std::is_convertible< + typename std::iterator_traits<ItTy>::iterator_category, + std::input_iterator_tag>::value>> + iterator insert(iterator I, ItTy From, ItTy To) { + // Convert iterator to elt# to avoid invalidating iterator when we reserve() + size_t InsertElt = I - this->begin(); + + if (I == this->end()) { // Important special case for empty vector. + append(From, To); + return this->begin() + InsertElt; + } + + assert(this->isReferenceToStorage(I) && "Insertion iterator is out of bounds."); + + // Check that the reserve that follows doesn't invalidate the iterators. + this->assertSafeToAddRange(From, To); + + size_t NumToInsert = std::distance(From, To); + + // Ensure there is enough space. + reserve(this->size() + NumToInsert); + + // Uninvalidate the iterator. + I = this->begin() + InsertElt; + + // If there are more elements between the insertion point and the end of the + // range than there are being inserted, we can use a simple approach to + // insertion. Since we already reserved space, we know that this won't + // reallocate the vector. + if (size_t(this->end() - I) >= NumToInsert) { + T* OldEnd = this->end(); + append(std::move_iterator<iterator>(this->end() - NumToInsert), + std::move_iterator<iterator>(this->end())); + + // Copy the existing elements that get replaced. + std::move_backward(I, OldEnd - NumToInsert, OldEnd); + + std::copy(From, To, I); + return I; + } + + // Otherwise, we're inserting more elements than exist already, and we're + // not inserting at the end. + + // Move over the elements that we're about to overwrite. + T* OldEnd = this->end(); + this->set_size(this->size() + NumToInsert); + size_t NumOverwritten = OldEnd - I; + this->uninitialized_move(I, OldEnd, this->end() - NumOverwritten); + + // Replace the overwritten part. + for (T* J = I; NumOverwritten > 0; --NumOverwritten) { + *J = *From; + ++J; + ++From; + } + + // Insert the non-overwritten middle part. + this->uninitialized_copy(From, To, OldEnd); + return I; + } + + void insert(iterator I, std::initializer_list<T> IL) { + insert(I, IL.begin(), IL.end()); + } + + template <typename... ArgTypes> + reference emplace_back(ArgTypes&&... Args) { + if (LLVM_UNLIKELY(this->size() >= this->capacity())) + return this->growAndEmplaceBack(std::forward<ArgTypes>(Args)...); + + ::new ((void*)this->end()) T(std::forward<ArgTypes>(Args)...); + this->set_size(this->size() + 1); + return this->back(); + } + + SmallVectorImpl& operator=(const SmallVectorImpl& RHS); + + SmallVectorImpl& operator=(SmallVectorImpl&& RHS); + + bool operator==(const SmallVectorImpl& RHS) const { + if (this->size() != RHS.size()) return false; + return std::equal(this->begin(), this->end(), RHS.begin()); + } + bool operator!=(const SmallVectorImpl& RHS) const { + return !(*this == RHS); + } + + bool operator<(const SmallVectorImpl& RHS) const { + return std::lexicographical_compare(this->begin(), this->end(), RHS.begin(), RHS.end()); + } +}; + +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 (!this->isSmall() && !RHS.isSmall()) { + std::swap(this->BeginX, RHS.BeginX); + std::swap(this->Size, RHS.Size); + std::swap(this->Capacity, RHS.Capacity); + return; + } + this->reserve(RHS.size()); + RHS.reserve(this->size()); + + // Swap the shared elements. + size_t NumShared = this->size(); + if (NumShared > RHS.size()) NumShared = RHS.size(); + for (size_type i = 0; i != NumShared; ++i) + std::swap((*this)[i], RHS[i]); + + // Copy over the extra elts. + if (this->size() > RHS.size()) { + size_t EltDiff = this->size() - RHS.size(); + this->uninitialized_copy(this->begin() + NumShared, this->end(), RHS.end()); + RHS.set_size(RHS.size() + EltDiff); + this->destroy_range(this->begin() + NumShared, this->end()); + this->set_size(NumShared); + } else if (RHS.size() > this->size()) { + size_t EltDiff = RHS.size() - this->size(); + this->uninitialized_copy(RHS.begin() + NumShared, RHS.end(), this->end()); + this->set_size(this->size() + EltDiff); + this->destroy_range(RHS.begin() + NumShared, RHS.end()); + RHS.set_size(NumShared); + } +} + +template <typename T> +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. + size_t RHSSize = RHS.size(); + size_t CurSize = this->size(); + if (CurSize >= RHSSize) { + // Assign common elements. + iterator NewEnd; + if (RHSSize) + NewEnd = std::copy(RHS.begin(), RHS.begin() + RHSSize, this->begin()); + else + NewEnd = this->begin(); + + // Destroy excess elements. + this->destroy_range(NewEnd, this->end()); + + // Trim. + this->set_size(RHSSize); + 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. + // FIXME: don't do this if they're efficiently moveable. + if (this->capacity() < RHSSize) { + // Destroy current elements. + this->clear(); + CurSize = 0; + this->grow(RHSSize); + } else if (CurSize) { + // Otherwise, use assignment for the already-constructed elements. + std::copy(RHS.begin(), RHS.begin() + CurSize, this->begin()); + } + + // Copy construct the new elements in place. + this->uninitialized_copy(RHS.begin() + CurSize, RHS.end(), this->begin() + CurSize); + + // Set end. + this->set_size(RHSSize); + return *this; +} + +template <typename T> +SmallVectorImpl<T>& SmallVectorImpl<T>::operator=(SmallVectorImpl<T>&& RHS) { + // Avoid self-assignment. + if (this == &RHS) return *this; + + // If the RHS isn't small, clear this vector and then steal its buffer. + if (!RHS.isSmall()) { + this->assignRemote(std::move(RHS)); + return *this; + } + + // If we already have sufficient space, assign the common elements, then + // destroy any excess. + size_t RHSSize = RHS.size(); + size_t CurSize = this->size(); + if (CurSize >= RHSSize) { + // Assign common elements. + iterator NewEnd = this->begin(); + if (RHSSize) + NewEnd = std::move(RHS.begin(), RHS.end(), NewEnd); + + // Destroy excess elements and trim the bounds. + this->destroy_range(NewEnd, this->end()); + this->set_size(RHSSize); + + // Clear the RHS. + RHS.clear(); + + 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. + // FIXME: this may not actually make any sense if we can efficiently move + // elements. + if (this->capacity() < RHSSize) { + // Destroy current elements. + this->clear(); + CurSize = 0; + this->grow(RHSSize); + } else if (CurSize) { + // Otherwise, use assignment for the already-constructed elements. + std::move(RHS.begin(), RHS.begin() + CurSize, this->begin()); + } + + // Move-construct the new elements in place. + this->uninitialized_move(RHS.begin() + CurSize, RHS.end(), this->begin() + CurSize); + + // Set end. + this->set_size(RHSSize); + + RHS.clear(); + return *this; +} + +/// Storage for the SmallVector elements. This is specialized for the N=0 case +/// to avoid allocating unnecessary storage. +template <typename T, unsigned N> +struct SmallVectorStorage { + alignas(T) char InlineElts[N * sizeof(T)]; +}; + +/// We need the storage to be properly aligned even for small-size of 0 so that +/// the pointer math in \a SmallVectorTemplateCommon::getFirstEl() is +/// well-defined. +template <typename T> +struct alignas(T) SmallVectorStorage<T, 0> {}; + +/// Forward declaration of SmallVector so that +/// calculateSmallVectorDefaultInlinedElements can reference +/// `sizeof(SmallVector<T, 0>)`. +template <typename T, unsigned N> +class SmallVector; + +/// Helper class for calculating the default number of inline elements for +/// `SmallVector<T>`. +/// +/// This should be migrated to a constexpr function when our minimum +/// compiler support is enough for multi-statement constexpr functions. +template <typename T> +struct CalculateSmallVectorDefaultInlinedElements { + // Parameter controlling the default number of inlined elements + // for `SmallVector<T>`. + // + // The default number of inlined elements ensures that + // 1. There is at least one inlined element. + // 2. `sizeof(SmallVector<T>) <= kPreferredSmallVectorSizeof` unless + // it contradicts 1. + static constexpr size_t kPreferredSmallVectorSizeof = 64; + + // static_assert that sizeof(T) is not "too big". + // + // Because our policy guarantees at least one inlined element, it is possible + // for an arbitrarily large inlined element to allocate an arbitrarily large + // amount of inline storage. We generally consider it an antipattern for a + // SmallVector to allocate an excessive amount of inline storage, so we want + // to call attention to these cases and make sure that users are making an + // intentional decision if they request a lot of inline storage. + // + // We want this assertion to trigger in pathological cases, but otherwise + // not be too easy to hit. To accomplish that, the cutoff is actually somewhat + // larger than kPreferredSmallVectorSizeof (otherwise, + // `SmallVector<SmallVector<T>>` would be one easy way to trip it, and that + // pattern seems useful in practice). + // + // One wrinkle is that this assertion is in theory non-portable, since + // sizeof(T) is in general platform-dependent. However, we don't expect this + // to be much of an issue, because most LLVM development happens on 64-bit + // hosts, and therefore sizeof(T) is expected to *decrease* when compiled for + // 32-bit hosts, dodging the issue. The reverse situation, where development + // happens on a 32-bit host and then fails due to sizeof(T) *increasing* on a + // 64-bit host, is expected to be very rare. + static_assert( + sizeof(T) <= 256, + "You are trying to use a default number of inlined elements for " + "`SmallVector<T>` but `sizeof(T)` is really big! Please use an " + "explicit number of inlined elements with `SmallVector<T, N>` to make " + "sure you really want that much inline storage."); + + // Discount the size of the header itself when calculating the maximum inline + // bytes. + static constexpr size_t PreferredInlineBytes = + kPreferredSmallVectorSizeof - sizeof(SmallVector<T, 0>); + static constexpr size_t NumElementsThatFit = PreferredInlineBytes / sizeof(T); + static constexpr size_t value = + NumElementsThatFit == 0 ? 1 : NumElementsThatFit; +}; + +/// 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 +/// In the absence of a well-motivated choice for the number of inlined +/// elements \p N, it is recommended to use \c SmallVector<T> (that is, +/// omitting the \p N). This will choose a default number of inlined elements +/// reasonable for allocation on the stack (for example, trying to keep \c +/// sizeof(SmallVector<T>) around 64 bytes). +/// +/// \warning This does not attempt to be exception safe. +/// +/// \see https://llvm.org/docs/ProgrammersManual.html#llvm-adt-smallvector-h +template <typename T, + unsigned N = CalculateSmallVectorDefaultInlinedElements<T>::value> +class SmallVector : public SmallVectorImpl<T>, + SmallVectorStorage<T, N> { +public: + SmallVector() + : SmallVectorImpl<T>(N) {} + + ~SmallVector() { + // Destroy the constructed elements in the vector. + this->destroy_range(this->begin(), this->end()); + } + + explicit SmallVector(size_t Size, const T& Value = T()) + : SmallVectorImpl<T>(N) { + this->assign(Size, Value); + } + + template <typename ItTy, + typename = std::enable_if_t<std::is_convertible< + typename std::iterator_traits<ItTy>::iterator_category, + std::input_iterator_tag>::value>> + SmallVector(ItTy S, ItTy E) + : SmallVectorImpl<T>(N) { + this->append(S, E); + } + + template <typename RangeTy> + explicit SmallVector(const iterator_range<RangeTy>& R) + : SmallVectorImpl<T>(N) { + this->append(R.begin(), R.end()); + } + + SmallVector(std::initializer_list<T> IL) + : SmallVectorImpl<T>(N) { + this->assign(IL); + } + + SmallVector(const SmallVector& RHS) + : SmallVectorImpl<T>(N) { + if (!RHS.empty()) + SmallVectorImpl<T>::operator=(RHS); + } + + SmallVector& operator=(const SmallVector& RHS) { + SmallVectorImpl<T>::operator=(RHS); + return *this; + } + + SmallVector(SmallVector&& RHS) + : SmallVectorImpl<T>(N) { + if (!RHS.empty()) + SmallVectorImpl<T>::operator=(::std::move(RHS)); + } + + SmallVector(SmallVectorImpl<T>&& RHS) + : SmallVectorImpl<T>(N) { + if (!RHS.empty()) + SmallVectorImpl<T>::operator=(::std::move(RHS)); + } + + SmallVector& operator=(SmallVector&& RHS) { + if (N) { + SmallVectorImpl<T>::operator=(::std::move(RHS)); + return *this; + } + // SmallVectorImpl<T>::operator= does not leverage N==0. Optimize the + // case. + if (this == &RHS) + return *this; + if (RHS.empty()) { + this->destroy_range(this->begin(), this->end()); + this->Size = 0; + } else { + this->assignRemote(std::move(RHS)); + } + return *this; + } + + SmallVector& operator=(SmallVectorImpl<T>&& RHS) { + SmallVectorImpl<T>::operator=(::std::move(RHS)); + return *this; + } + + SmallVector& operator=(std::initializer_list<T> IL) { + this->assign(IL); + return *this; + } +}; + +template <typename T, unsigned N> +inline size_t capacity_in_bytes(const SmallVector<T, N>& X) { + return X.capacity_in_bytes(); +} + +template <typename RangeType> +using ValueTypeFromRangeType = + typename std::remove_const<typename std::remove_reference< + decltype(*std::begin(std::declval<RangeType&>()))>::type>::type; + +/// Given a range of type R, iterate the entire range and return a +/// SmallVector with elements of the vector. This is useful, for example, +/// when you want to iterate a range and then sort the results. +template <unsigned Size, typename R> +SmallVector<ValueTypeFromRangeType<R>, Size> to_vector(R&& Range) { + return { std::begin(Range), std::end(Range) }; +} +template <typename R> +SmallVector<ValueTypeFromRangeType<R>, + CalculateSmallVectorDefaultInlinedElements< + ValueTypeFromRangeType<R>>::value> +to_vector(R&& Range) { + return { std::begin(Range), std::end(Range) }; +} + +namespace std { + +/// Implement std::swap in terms of SmallVector swap. +template <typename T> +inline void swap(SmallVectorImpl<T>& LHS, SmallVectorImpl<T>& RHS) { + LHS.swap(RHS); +} + +/// Implement std::swap in terms of SmallVector swap. +template <typename T, unsigned N> +inline void swap(SmallVector<T, N>& LHS, SmallVector<T, N>& RHS) { + LHS.swap(RHS); +} + +} // namespace std + +#ifdef _MSC_VER +# pragma warning(pop) +#endif |