llvm-6502/include/llvm/ADT/SmallVector.h
Richard Trieu 0ac7e6f293 Add asserts to SmallVector so that calls to front() and back() only succeed
if the vector is not empty.  This will ensure that calls to these functions
will reference elements in the vector.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173321 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-24 04:29:24 +00:00

943 lines
29 KiB
C++

//===- 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/Support/AlignOf.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/type_traits.h"
#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <iterator>
#include <memory>
namespace llvm {
/// SmallVectorBase - This is all the non-templated stuff common to all
/// SmallVectors.
class SmallVectorBase {
protected:
void *BeginX, *EndX, *CapacityX;
protected:
SmallVectorBase(void *FirstEl, size_t Size)
: BeginX(FirstEl), EndX(FirstEl), CapacityX((char*)FirstEl+Size) {}
/// grow_pod - 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.
void grow_pod(void *FirstEl, size_t MinSizeInBytes, size_t TSize);
public:
/// size_in_bytes - This returns size()*sizeof(T).
size_t size_in_bytes() const {
return size_t((char*)EndX - (char*)BeginX);
}
/// capacity_in_bytes - This returns capacity()*sizeof(T).
size_t capacity_in_bytes() const {
return size_t((char*)CapacityX - (char*)BeginX);
}
bool empty() const { return BeginX == EndX; }
};
template <typename T, unsigned N> struct SmallVectorStorage;
/// SmallVectorTemplateCommon - 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 {
private:
template <typename, unsigned> friend struct SmallVectorStorage;
// 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. Use an array of char of sufficient alignment.
typedef llvm::AlignedCharArrayUnion<T> U;
U FirstEl;
// Space after 'FirstEl' is clobbered, do not add any instance vars after it.
protected:
SmallVectorTemplateCommon(size_t Size) : SmallVectorBase(&FirstEl, Size) {}
void grow_pod(size_t MinSizeInBytes, size_t TSize) {
SmallVectorBase::grow_pod(&FirstEl, MinSizeInBytes, TSize);
}
/// isSmall - Return true if this is a smallvector which has not had dynamic
/// memory allocated for it.
bool isSmall() const {
return BeginX == static_cast<const void*>(&FirstEl);
}
/// resetToSmall - Put this vector in a state of being small.
void resetToSmall() {
BeginX = EndX = CapacityX = &FirstEl;
}
void setEnd(T *P) { this->EndX = P; }
public:
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;
// forward iterator creation methods.
iterator begin() { return (iterator)this->BeginX; }
const_iterator begin() const { return (const_iterator)this->BeginX; }
iterator end() { return (iterator)this->EndX; }
const_iterator end() const { return (const_iterator)this->EndX; }
protected:
iterator capacity_ptr() { return (iterator)this->CapacityX; }
const_iterator capacity_ptr() const { return (const_iterator)this->CapacityX;}
public:
// 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() const { return end()-begin(); }
size_type max_size() const { return size_type(-1) / sizeof(T); }
/// capacity - Return the total number of elements in the currently allocated
/// buffer.
size_t capacity() const { return capacity_ptr() - begin(); }
/// data - Return a pointer to the vector's buffer, even if empty().
pointer data() { return pointer(begin()); }
/// data - Return a pointer to the vector's buffer, even if empty().
const_pointer data() const { return const_pointer(begin()); }
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() {
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<isPodLike = false> - This is where we put method
/// implementations that are designed to work with non-POD-like T's.
template <typename T, bool isPodLike>
class SmallVectorTemplateBase : public SmallVectorTemplateCommon<T> {
protected:
SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
static void destroy_range(T *S, T *E) {
while (S != E) {
--E;
E->~T();
}
}
/// move - Use move-assignment to move the range [I, E) onto the
/// objects starting with "Dest". This is just <memory>'s
/// std::move, but not all stdlibs actually provide that.
template<typename It1, typename It2>
static It2 move(It1 I, It1 E, It2 Dest) {
#if LLVM_HAS_RVALUE_REFERENCES
for (; I != E; ++I, ++Dest)
*Dest = ::std::move(*I);
return Dest;
#else
return ::std::copy(I, E, Dest);
#endif
}
/// move_backward - Use move-assignment to move the range
/// [I, E) onto the objects ending at "Dest", moving objects
/// in reverse order. This is just <algorithm>'s
/// std::move_backward, but not all stdlibs actually provide that.
template<typename It1, typename It2>
static It2 move_backward(It1 I, It1 E, It2 Dest) {
#if LLVM_HAS_RVALUE_REFERENCES
while (I != E)
*--Dest = ::std::move(*--E);
return Dest;
#else
return ::std::copy_backward(I, E, Dest);
#endif
}
/// uninitialized_move - 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) {
#if LLVM_HAS_RVALUE_REFERENCES
for (; I != E; ++I, ++Dest)
::new ((void*) &*Dest) T(::std::move(*I));
#else
::std::uninitialized_copy(I, E, Dest);
#endif
}
/// uninitialized_copy - 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 - 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);
public:
void push_back(const T &Elt) {
if (this->EndX < this->CapacityX) {
Retry:
::new ((void*) this->end()) T(Elt);
this->setEnd(this->end()+1);
return;
}
this->grow();
goto Retry;
}
#if LLVM_HAS_RVALUE_REFERENCES
void push_back(T &&Elt) {
if (this->EndX < this->CapacityX) {
Retry:
::new ((void*) this->end()) T(::std::move(Elt));
this->setEnd(this->end()+1);
return;
}
this->grow();
goto Retry;
}
#endif
void pop_back() {
this->setEnd(this->end()-1);
this->end()->~T();
}
};
// Define this out-of-line to dissuade the C++ compiler from inlining it.
template <typename T, bool isPodLike>
void SmallVectorTemplateBase<T, isPodLike>::grow(size_t MinSize) {
size_t CurCapacity = this->capacity();
size_t CurSize = this->size();
size_t NewCapacity = 2*CurCapacity + 1; // Always grow, even from zero.
if (NewCapacity < MinSize)
NewCapacity = MinSize;
T *NewElts = static_cast<T*>(malloc(NewCapacity*sizeof(T)));
// Move the elements over.
this->uninitialized_move(this->begin(), this->end(), NewElts);
// Destroy the original elements.
destroy_range(this->begin(), this->end());
// If this wasn't grown from the inline copy, deallocate the old space.
if (!this->isSmall())
free(this->begin());
this->setEnd(NewElts+CurSize);
this->BeginX = NewElts;
this->CapacityX = this->begin()+NewCapacity;
}
/// SmallVectorTemplateBase<isPodLike = true> - This is where we put method
/// implementations that are designed to work with POD-like T's.
template <typename T>
class SmallVectorTemplateBase<T, true> : public SmallVectorTemplateCommon<T> {
protected:
SmallVectorTemplateBase(size_t Size) : SmallVectorTemplateCommon<T>(Size) {}
// No need to do a destroy loop for POD's.
static void destroy_range(T *, T *) {}
/// move - Use move-assignment to move the range [I, E) onto the
/// objects starting with "Dest". For PODs, this is just memcpy.
template<typename It1, typename It2>
static It2 move(It1 I, It1 E, It2 Dest) {
return ::std::copy(I, E, Dest);
}
/// move_backward - Use move-assignment to move the range
/// [I, E) onto the objects ending at "Dest", moving objects
/// in reverse order.
template<typename It1, typename It2>
static It2 move_backward(It1 I, It1 E, It2 Dest) {
return ::std::copy_backward(I, E, Dest);
}
/// uninitialized_move - 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);
}
/// uninitialized_copy - 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);
}
/// uninitialized_copy - 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) {
// Use memcpy for PODs iterated by pointers (which includes SmallVector
// iterators): std::uninitialized_copy optimizes to memmove, but we can
// use memcpy here.
memcpy(Dest, I, (E-I)*sizeof(T));
}
/// grow - 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), sizeof(T));
}
public:
void push_back(const T &Elt) {
if (this->EndX < this->CapacityX) {
Retry:
memcpy(this->end(), &Elt, sizeof(T));
this->setEnd(this->end()+1);
return;
}
this->grow();
goto Retry;
}
void pop_back() {
this->setEnd(this->end()-1);
}
};
/// 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 : public SmallVectorTemplateBase<T, isPodLike<T>::value> {
typedef SmallVectorTemplateBase<T, isPodLike<T>::value > SuperClass;
SmallVectorImpl(const SmallVectorImpl&) LLVM_DELETED_FUNCTION;
public:
typedef typename SuperClass::iterator iterator;
typedef typename SuperClass::size_type size_type;
protected:
// Default ctor - Initialize to empty.
explicit SmallVectorImpl(unsigned N)
: SmallVectorTemplateBase<T, isPodLike<T>::value>(N*sizeof(T)) {
}
public:
~SmallVectorImpl() {
// Destroy the constructed elements in the vector.
this->destroy_range(this->begin(), this->end());
// 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->EndX = this->BeginX;
}
void resize(unsigned N) {
if (N < this->size()) {
this->destroy_range(this->begin()+N, this->end());
this->setEnd(this->begin()+N);
} else if (N > this->size()) {
if (this->capacity() < N)
this->grow(N);
std::uninitialized_fill(this->end(), this->begin()+N, T());
this->setEnd(this->begin()+N);
}
}
void resize(unsigned N, const T &NV) {
if (N < this->size()) {
this->destroy_range(this->begin()+N, this->end());
this->setEnd(this->begin()+N);
} else if (N > this->size()) {
if (this->capacity() < N)
this->grow(N);
std::uninitialized_fill(this->end(), this->begin()+N, NV);
this->setEnd(this->begin()+N);
}
}
void reserve(unsigned N) {
if (this->capacity() < N)
this->grow(N);
}
T pop_back_val() {
#if LLVM_HAS_RVALUE_REFERENCES
T Result = ::std::move(this->back());
#else
T Result = this->back();
#endif
this->pop_back();
return Result;
}
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 (NumInputs > size_type(this->capacity_ptr()-this->end()))
this->grow(this->size()+NumInputs);
// Copy the new elements over.
// TODO: NEED To compile time dispatch on whether in_iter is a random access
// iterator to use the fast uninitialized_copy.
std::uninitialized_copy(in_start, in_end, this->end());
this->setEnd(this->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 (NumInputs > size_type(this->capacity_ptr()-this->end()))
this->grow(this->size()+NumInputs);
// Copy the new elements over.
std::uninitialized_fill_n(this->end(), NumInputs, Elt);
this->setEnd(this->end() + NumInputs);
}
void assign(unsigned NumElts, const T &Elt) {
clear();
if (this->capacity() < NumElts)
this->grow(NumElts);
this->setEnd(this->begin()+NumElts);
std::uninitialized_fill(this->begin(), this->end(), Elt);
}
iterator erase(iterator I) {
assert(I >= this->begin() && "Iterator to erase is out of bounds.");
assert(I < this->end() && "Erasing at past-the-end iterator.");
iterator N = I;
// Shift all elts down one.
this->move(I+1, this->end(), I);
// Drop the last elt.
this->pop_back();
return(N);
}
iterator erase(iterator S, iterator E) {
assert(S >= this->begin() && "Range to erase is out of bounds.");
assert(S <= E && "Trying to erase invalid range.");
assert(E <= this->end() && "Trying to erase past the end.");
iterator N = S;
// Shift all elts down.
iterator I = this->move(E, this->end(), S);
// Drop the last elts.
this->destroy_range(I, this->end());
this->setEnd(I);
return(N);
}
#if LLVM_HAS_RVALUE_REFERENCES
iterator insert(iterator I, T &&Elt) {
if (I == this->end()) { // Important special case for empty vector.
this->push_back(::std::move(Elt));
return this->end()-1;
}
assert(I >= this->begin() && "Insertion iterator is out of bounds.");
assert(I <= this->end() && "Inserting past the end of the vector.");
if (this->EndX < this->CapacityX) {
Retry:
::new ((void*) this->end()) T(::std::move(this->back()));
this->setEnd(this->end()+1);
// Push everything else over.
this->move_backward(I, this->end()-1, this->end());
// If we just moved the element we're inserting, be sure to update
// the reference.
T *EltPtr = &Elt;
if (I <= EltPtr && EltPtr < this->EndX)
++EltPtr;
*I = ::std::move(*EltPtr);
return I;
}
size_t EltNo = I-this->begin();
this->grow();
I = this->begin()+EltNo;
goto Retry;
}
#endif
iterator insert(iterator I, const T &Elt) {
if (I == this->end()) { // Important special case for empty vector.
this->push_back(Elt);
return this->end()-1;
}
assert(I >= this->begin() && "Insertion iterator is out of bounds.");
assert(I <= this->end() && "Inserting past the end of the vector.");
if (this->EndX < this->CapacityX) {
Retry:
::new ((void*) this->end()) T(this->back());
this->setEnd(this->end()+1);
// Push everything else over.
this->move_backward(I, this->end()-1, this->end());
// If we just moved the element we're inserting, be sure to update
// the reference.
const T *EltPtr = &Elt;
if (I <= EltPtr && EltPtr < this->EndX)
++EltPtr;
*I = *EltPtr;
return I;
}
size_t EltNo = I-this->begin();
this->grow();
I = this->begin()+EltNo;
goto Retry;
}
iterator insert(iterator I, size_type NumToInsert, const T &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(I >= this->begin() && "Insertion iterator is out of bounds.");
assert(I <= this->end() && "Inserting past the end of the vector.");
// Ensure there is enough space.
reserve(static_cast<unsigned>(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(this->end()-NumToInsert, this->end());
// Copy the existing elements that get replaced.
this->move_backward(I, OldEnd-NumToInsert, OldEnd);
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.
// Move over the elements that we're about to overwrite.
T *OldEnd = this->end();
this->setEnd(this->end() + NumToInsert);
size_t NumOverwritten = OldEnd-I;
this->uninitialized_move(I, OldEnd, this->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) {
// 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(I >= this->begin() && "Insertion iterator is out of bounds.");
assert(I <= this->end() && "Inserting past the end of the vector.");
size_t NumToInsert = std::distance(From, To);
// Ensure there is enough space.
reserve(static_cast<unsigned>(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(this->end()-NumToInsert, this->end());
// Copy the existing elements that get replaced.
this->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->setEnd(this->end() + 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;
}
SmallVectorImpl &operator=(const SmallVectorImpl &RHS);
#if LLVM_HAS_RVALUE_REFERENCES
SmallVectorImpl &operator=(SmallVectorImpl &&RHS);
#endif
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());
}
/// 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.
///
/// Clients can use this in conjunction with capacity() to write past the end
/// of the buffer when they know that more elements are available, and only
/// update the size later. This avoids the cost of value initializing elements
/// which will only be overwritten.
void set_size(unsigned N) {
assert(N <= this->capacity());
this->setEnd(this->begin() + N);
}
};
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->EndX, RHS.EndX);
std::swap(this->CapacityX, RHS.CapacityX);
return;
}
if (RHS.size() > this->capacity())
this->grow(RHS.size());
if (this->size() > RHS.capacity())
RHS.grow(this->size());
// Swap the shared elements.
size_t NumShared = this->size();
if (NumShared > RHS.size()) NumShared = RHS.size();
for (unsigned i = 0; i != static_cast<unsigned>(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.setEnd(RHS.end()+EltDiff);
this->destroy_range(this->begin()+NumShared, this->end());
this->setEnd(this->begin()+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->setEnd(this->end() + EltDiff);
this->destroy_range(RHS.begin()+NumShared, RHS.end());
RHS.setEnd(RHS.begin()+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->setEnd(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.
// FIXME: don't do this if they're efficiently moveable.
if (this->capacity() < RHSSize) {
// Destroy current elements.
this->destroy_range(this->begin(), this->end());
this->setEnd(this->begin());
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->setEnd(this->begin()+RHSSize);
return *this;
}
#if LLVM_HAS_RVALUE_REFERENCES
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->destroy_range(this->begin(), this->end());
if (!this->isSmall()) free(this->begin());
this->BeginX = RHS.BeginX;
this->EndX = RHS.EndX;
this->CapacityX = RHS.CapacityX;
RHS.resetToSmall();
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 = this->move(RHS.begin(), RHS.end(), NewEnd);
// Destroy excess elements and trim the bounds.
this->destroy_range(NewEnd, this->end());
this->setEnd(NewEnd);
// 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->destroy_range(this->begin(), this->end());
this->setEnd(this->begin());
CurSize = 0;
this->grow(RHSSize);
} else if (CurSize) {
// Otherwise, use assignment for the already-constructed elements.
this->move(RHS.begin(), RHS.end(), this->begin());
}
// Move-construct the new elements in place.
this->uninitialized_move(RHS.begin()+CurSize, RHS.end(),
this->begin()+CurSize);
// Set end.
this->setEnd(this->begin()+RHSSize);
RHS.clear();
return *this;
}
#endif
/// Storage for the SmallVector elements which aren't contained in
/// SmallVectorTemplateCommon. There are 'N-1' elements here. The remaining '1'
/// element is in the base class. This is specialized for the N=1 and N=0 cases
/// to avoid allocating unnecessary storage.
template <typename T, unsigned N>
struct SmallVectorStorage {
typename SmallVectorTemplateCommon<T>::U InlineElts[N - 1];
};
template <typename T> struct SmallVectorStorage<T, 1> {};
template <typename T> struct SmallVectorStorage<T, 0> {};
/// 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> {
/// Storage - Inline space for elements which aren't stored in the base class.
SmallVectorStorage<T, N> Storage;
public:
SmallVector() : SmallVectorImpl<T>(N) {
}
explicit SmallVector(unsigned Size, const T &Value = T())
: SmallVectorImpl<T>(N) {
this->assign(Size, Value);
}
template<typename ItTy>
SmallVector(ItTy S, ItTy E) : SmallVectorImpl<T>(N) {
this->append(S, E);
}
SmallVector(const SmallVector &RHS) : SmallVectorImpl<T>(N) {
if (!RHS.empty())
SmallVectorImpl<T>::operator=(RHS);
}
const SmallVector &operator=(const SmallVector &RHS) {
SmallVectorImpl<T>::operator=(RHS);
return *this;
}
#if LLVM_HAS_RVALUE_REFERENCES
SmallVector(SmallVector &&RHS) : SmallVectorImpl<T>(N) {
if (!RHS.empty())
SmallVectorImpl<T>::operator=(::std::move(RHS));
}
const SmallVector &operator=(SmallVector &&RHS) {
SmallVectorImpl<T>::operator=(::std::move(RHS));
return *this;
}
#endif
};
template<typename T, unsigned N>
static inline size_t capacity_in_bytes(const SmallVector<T, N> &X) {
return X.capacity_in_bytes();
}
} // 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