LLVM 22.0.0git
simple_ilist.h
Go to the documentation of this file.
1//===- llvm/ADT/simple_ilist.h - Simple Intrusive List ----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLVM_ADT_SIMPLE_ILIST_H
10#define LLVM_ADT_SIMPLE_ILIST_H
11
12#include "llvm/ADT/ilist_base.h"
14#include "llvm/ADT/ilist_node.h"
17#include <algorithm>
18#include <cassert>
19#include <cstddef>
20#include <functional>
21#include <iterator>
22#include <utility>
23
24namespace llvm {
25
26/// A simple intrusive list implementation.
27///
28/// This is a simple intrusive list for a \c T that inherits from \c
29/// ilist_node<T>. The list never takes ownership of anything inserted in it.
30///
31/// Unlike \a iplist<T> and \a ilist<T>, \a simple_ilist<T> never deletes
32/// values, and has no callback traits.
33///
34/// The API for adding nodes include \a push_front(), \a push_back(), and \a
35/// insert(). These all take values by reference (not by pointer), except for
36/// the range version of \a insert().
37///
38/// There are three sets of API for discarding nodes from the list: \a
39/// remove(), which takes a reference to the node to remove, \a erase(), which
40/// takes an iterator or iterator range and returns the next one, and \a
41/// clear(), which empties out the container. All three are constant time
42/// operations. None of these deletes any nodes; in particular, if there is a
43/// single node in the list, then these have identical semantics:
44/// \li \c L.remove(L.front());
45/// \li \c L.erase(L.begin());
46/// \li \c L.clear();
47///
48/// As a convenience for callers, there are parallel APIs that take a \c
49/// Disposer (such as \c std::default_delete<T>): \a removeAndDispose(), \a
50/// eraseAndDispose(), and \a clearAndDispose(). These have different names
51/// because the extra semantic is otherwise non-obvious. They are equivalent
52/// to calling \a std::for_each() on the range to be discarded.
53///
54/// The currently available \p Options customize the nodes in the list. The
55/// same options must be specified in the \a ilist_node instantiation for
56/// compatibility (although the order is irrelevant).
57/// \li Use \a ilist_tag to designate which ilist_node for a given \p T this
58/// list should use. This is useful if a type \p T is part of multiple,
59/// independent lists simultaneously.
60/// \li Use \a ilist_sentinel_tracking to always (or never) track whether a
61/// node is a sentinel. Specifying \c true enables the \a
62/// ilist_node::isSentinel() API. Unlike \a ilist_node::isKnownSentinel(),
63/// which is only appropriate for assertions, \a ilist_node::isSentinel() is
64/// appropriate for real logic.
65///
66/// Here are examples of \p Options usage:
67/// \li \c simple_ilist<T> gives the defaults. \li \c
68/// simple_ilist<T,ilist_sentinel_tracking<true>> enables the \a
69/// ilist_node::isSentinel() API.
70/// \li \c simple_ilist<T,ilist_tag<A>,ilist_sentinel_tracking<false>>
71/// specifies a tag of A and that tracking should be off (even when
72/// LLVM_ENABLE_ABI_BREAKING_CHECKS are enabled).
73/// \li \c simple_ilist<T,ilist_sentinel_tracking<false>,ilist_tag<A>> is
74/// equivalent to the last.
75///
76/// See \a is_valid_option for steps on adding a new option.
77template <typename T, class... Options>
79 : ilist_detail::compute_node_options<T, Options...>::type::list_base_type,
81 typename ilist_detail::compute_node_options<T, Options...>::type> {
82 static_assert(ilist_detail::check_options<Options...>::value,
83 "Unrecognized node option!");
84 using OptionsT =
86 using list_base_type = typename OptionsT::list_base_type;
88
89public:
90 using value_type = typename OptionsT::value_type;
91 using pointer = typename OptionsT::pointer;
92 using reference = typename OptionsT::reference;
93 using const_pointer = typename OptionsT::const_pointer;
94 using const_reference = typename OptionsT::const_reference;
100 using size_type = size_t;
102
103 simple_ilist() = default;
104 ~simple_ilist() = default;
105
106 // No copy constructors.
107 simple_ilist(const simple_ilist &) = delete;
109
110 // Move constructors.
113 clear();
114 splice(end(), X);
115 return *this;
116 }
117
118 iterator begin() { return ++iterator(Sentinel); }
119 const_iterator begin() const { return ++const_iterator(Sentinel); }
120 iterator end() { return iterator(Sentinel); }
121 const_iterator end() const { return const_iterator(Sentinel); }
122 reverse_iterator rbegin() { return ++reverse_iterator(Sentinel); }
124 return ++const_reverse_iterator(Sentinel);
125 }
126 reverse_iterator rend() { return reverse_iterator(Sentinel); }
128 return const_reverse_iterator(Sentinel);
129 }
130
131 /// Check if the list is empty in constant time.
132 [[nodiscard]] bool empty() const { return Sentinel.empty(); }
133
134 /// Calculate the size of the list in linear time.
135 [[nodiscard]] size_type size() const { return std::distance(begin(), end()); }
136
137 reference front() { return *begin(); }
138 const_reference front() const { return *begin(); }
139 reference back() { return *rbegin(); }
140 const_reference back() const { return *rbegin(); }
141
142 /// Insert a node at the front; never copies.
144
145 /// Insert a node at the back; never copies.
147
148 /// Remove the node at the front; never deletes.
149 void pop_front() { erase(begin()); }
150
151 /// Remove the node at the back; never deletes.
152 void pop_back() { erase(--end()); }
153
154 /// Swap with another list in place using std::swap.
155 void swap(simple_ilist &X) { std::swap(*this, X); }
156
157 /// Insert a node by reference; never copies.
159 list_base_type::insertBefore(*I.getNodePtr(), *this->getNodePtr(&Node));
160 return iterator(&Node);
161 }
162
163 /// Insert a range of nodes; never copies.
164 template <class Iterator>
165 void insert(iterator I, Iterator First, Iterator Last) {
166 for (; First != Last; ++First)
167 insert(I, *First);
168 }
169
170 /// Clone another list.
171 template <class Cloner, class Disposer>
172 void cloneFrom(const simple_ilist &L2, Cloner clone, Disposer dispose) {
173 clearAndDispose(dispose);
174 for (const_reference V : L2)
175 push_back(*clone(V));
176 }
177
178 /// Remove a node by reference; never deletes.
179 ///
180 /// \see \a erase() for removing by iterator.
181 /// \see \a removeAndDispose() if the node should be deleted.
182 void remove(reference N) { list_base_type::remove(*this->getNodePtr(&N)); }
183
184 /// Remove a node by reference and dispose of it.
185 template <class Disposer>
186 void removeAndDispose(reference N, Disposer dispose) {
187 remove(N);
188 dispose(&N);
189 }
190
191 /// Remove a node by iterator; never deletes.
192 ///
193 /// \see \a remove() for removing by reference.
194 /// \see \a eraseAndDispose() it the node should be deleted.
196 assert(I != end() && "Cannot remove end of list!");
197 remove(*I++);
198 return I;
199 }
200
201 /// Remove a range of nodes; never deletes.
202 ///
203 /// \see \a eraseAndDispose() if the nodes should be deleted.
205 list_base_type::removeRange(*First.getNodePtr(), *Last.getNodePtr());
206 return Last;
207 }
208
209 /// Remove a node by iterator and dispose of it.
210 template <class Disposer>
211 iterator eraseAndDispose(iterator I, Disposer dispose) {
212 auto Next = std::next(I);
213 erase(I);
214 dispose(&*I);
215 return Next;
216 }
217
218 /// Remove a range of nodes and dispose of them.
219 template <class Disposer>
221 while (First != Last)
222 First = eraseAndDispose(First, dispose);
223 return Last;
224 }
225
226 /// Clear the list; never deletes.
227 ///
228 /// \see \a clearAndDispose() if the nodes should be deleted.
229 void clear() { Sentinel.reset(); }
230
231 /// Clear the list and dispose of the nodes.
232 template <class Disposer> void clearAndDispose(Disposer dispose) {
233 eraseAndDispose(begin(), end(), dispose);
234 }
235
236 /// Splice in another list.
238 splice(I, L2, L2.begin(), L2.end());
239 }
240
241 /// Splice in a node from another list.
243 splice(I, L2, Node, std::next(Node));
244 }
245
246 /// Splice in a range of nodes from another list.
248 list_base_type::transferBefore(*I.getNodePtr(), *First.getNodePtr(),
249 *Last.getNodePtr());
250 }
251
252 /// Merge in another list.
253 ///
254 /// \pre \c this and \p RHS are sorted.
255 ///@{
256 void merge(simple_ilist &RHS) { merge(RHS, std::less<T>()); }
257 template <class Compare> void merge(simple_ilist &RHS, Compare comp);
258 ///@}
259
260 /// Sort the list.
261 ///@{
262 void sort() { sort(std::less<T>()); }
263 template <class Compare> void sort(Compare comp);
264 ///@}
265};
266
267template <class T, class... Options>
268template <class Compare>
270 if (this == &RHS || RHS.empty())
271 return;
272 iterator LI = begin(), LE = end();
273 iterator RI = RHS.begin(), RE = RHS.end();
274 while (LI != LE) {
275 if (comp(*RI, *LI)) {
276 // Transfer a run of at least size 1 from RHS to LHS.
277 iterator RunStart = RI++;
278 RI = std::find_if(RI, RE, [&](reference RV) { return !comp(RV, *LI); });
279 splice(LI, RHS, RunStart, RI);
280 if (RI == RE)
281 return;
282 }
283 ++LI;
284 }
285 // Transfer the remaining RHS nodes once LHS is finished.
286 splice(LE, RHS, RI, RE);
287}
288
289template <class T, class... Options>
290template <class Compare>
292 // Vacuously sorted.
293 if (empty() || std::next(begin()) == end())
294 return;
295
296 // Split the list in the middle.
297 iterator Center = begin(), End = begin();
298 while (End != end() && ++End != end()) {
299 ++Center;
300 ++End;
301 }
303 RHS.splice(RHS.end(), *this, Center, end());
304
305 // Sort the sublists and merge back together.
306 sort(comp);
307 RHS.sort(comp);
308 merge(RHS, comp);
309}
310
311} // end namespace llvm
312
313#endif // LLVM_ADT_SIMPLE_ILIST_H
assert(UImm &&(UImm !=~static_cast< T >(0)) &&"Invalid immediate!")
static LVOptions Options
Definition LVOptions.cpp:25
static LoopDeletionResult merge(LoopDeletionResult A, LoopDeletionResult B)
#define I(x, y, z)
Definition MD5.cpp:58
#define T
static TableGen::Emitter::OptClass< SkeletonEmitter > X("gen-skeleton-class", "Generate example skeleton class")
Value * RHS
typename OptionsT::reference reference
iterator eraseAndDispose(iterator First, iterator Last, Disposer dispose)
Remove a range of nodes and dispose of them.
iterator eraseAndDispose(iterator I, Disposer dispose)
Remove a node by iterator and dispose of it.
void splice(iterator I, simple_ilist &, iterator First, iterator Last)
Splice in a range of nodes from another list.
typename OptionsT::const_reference const_reference
simple_ilist(simple_ilist &&X)
simple_ilist & operator=(const simple_ilist &)=delete
const_reverse_iterator rend() const
const_reverse_iterator rbegin() const
void splice(iterator I, simple_ilist &L2)
Splice in another list.
const_reference front() const
simple_ilist & operator=(simple_ilist &&X)
void swap(simple_ilist &X)
Swap with another list in place using std::swap.
const_reference back() const
iterator erase(iterator I)
Remove a node by iterator; never deletes.
ilist_select_iterator_type< OptionsT, true, true > const_reverse_iterator
void sort(Compare comp)
void pop_back()
Remove the node at the back; never deletes.
simple_ilist(const simple_ilist &)=delete
void push_front(reference Node)
Insert a node at the front; never copies.
~simple_ilist()=default
void cloneFrom(const simple_ilist &L2, Cloner clone, Disposer dispose)
Clone another list.
iterator insert(iterator I, reference Node)
Insert a node by reference; never copies.
reverse_iterator rend()
ilist_select_iterator_type< OptionsT, true, false > reverse_iterator
void merge(simple_ilist &RHS, Compare comp)
void merge(simple_ilist &RHS)
Merge in another list.
const_iterator end() const
void clear()
Clear the list; never deletes.
simple_ilist()=default
void insert(iterator I, Iterator First, Iterator Last)
Insert a range of nodes; never copies.
const_iterator begin() const
bool empty() const
Check if the list is empty in constant time.
void pop_front()
Remove the node at the front; never deletes.
ilist_select_iterator_type< OptionsT, false, false > iterator
iterator erase(iterator First, iterator Last)
Remove a range of nodes; never deletes.
typename OptionsT::value_type value_type
void push_back(reference Node)
Insert a node at the back; never copies.
typename OptionsT::const_pointer const_pointer
ilist_select_iterator_type< OptionsT, false, true > const_iterator
void sort()
Sort the list.
void splice(iterator I, simple_ilist &L2, iterator Node)
Splice in a node from another list.
reverse_iterator rbegin()
void remove(reference N)
Remove a node by reference; never deletes.
void clearAndDispose(Disposer dispose)
Clear the list and dispose of the nodes.
typename OptionsT::pointer pointer
size_type size() const
Calculate the size of the list in linear time.
void removeAndDispose(reference N, Disposer dispose)
Remove a node by reference and dispose of it.
This file defines the ilist_node class template, which is a convenient base class for creating classe...
This is an optimization pass for GlobalISel generic memory operations.
std::conditional_t< OptionsT::has_iterator_bits, ilist_iterator_w_bits< OptionsT, IsReverse, IsConst >, ilist_iterator< OptionsT, IsReverse, IsConst > > ilist_select_iterator_type
Definition ilist_node.h:55
void sort(IteratorTy Start, IteratorTy End)
Definition STLExtras.h:1624
@ First
Helpers to iterate all locations in the MemoryEffectsBase class.
Definition ModRef.h:71
FunctionAddr VTableAddr Next
Definition InstrProf.h:141
void swap(llvm::BitVector &LHS, llvm::BitVector &RHS)
Implement std::swap in terms of BitVector swap.
Definition BitVector.h:872
#define N
Check whether options are valid.