1//===- AddressRanges.h ------------------------------------------*- 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_ADDRESSRANGES_H
10#define LLVM_ADT_ADDRESSRANGES_H
11
12#include "llvm/ADT/STLExtras.h"
13#include "llvm/ADT/SmallVector.h"
14#include <cassert>
15#include <optional>
16#include <stdint.h>
17
18namespace llvm {
19
20/// A class that represents an address range. The range is specified using
21/// a start and an end address: [Start, End).
22class AddressRange {
23public:
24  AddressRange() {}
25  AddressRange(uint64_t S, uint64_t E) : Start(S), End(E) {
26    assert(Start <= End);
27  }
28  uint64_t start() const { return Start; }
29  uint64_t end() const { return End; }
30  uint64_t size() const { return End - Start; }
31  uint64_t empty() const { return size() == 0; }
32  bool contains(uint64_t Addr) const { return Start <= Addr && Addr < End; }
33  bool contains(const AddressRange &R) const {
34    return Start <= R.Start && R.End <= End;
35  }
36  bool intersects(const AddressRange &R) const {
37    return Start < R.End && R.Start < End;
38  }
39  bool operator==(const AddressRange &R) const {
40    return Start == R.Start && End == R.End;
41  }
42  bool operator!=(const AddressRange &R) const { return !(*this == R); }
43  bool operator<(const AddressRange &R) const {
44    return std::make_pair(Start, End) < std::make_pair(R.Start, R.End);
45  }
46
47private:
48  uint64_t Start = 0;
49  uint64_t End = 0;
50};
51
52/// The AddressRangesBase class presents the base functionality for the
53/// normalized address ranges collection. This class keeps a sorted vector
54/// of AddressRange-like objects and can perform searches efficiently.
55/// The address ranges are always sorted and never contain any invalid,
56/// empty or intersected address ranges.
57
58template <typename T> class AddressRangesBase {
59protected:
60  using Collection = SmallVector<T>;
61  Collection Ranges;
62
63public:
64  void clear() { Ranges.clear(); }
65  bool empty() const { return Ranges.empty(); }
66  bool contains(uint64_t Addr) const {
67    return find(Addr, Addr + 1) != Ranges.end();
68  }
69  bool contains(AddressRange Range) const {
70    return find(Range.start(), Range.end()) != Ranges.end();
71  }
72  void reserve(size_t Capacity) { Ranges.reserve(Capacity); }
73  size_t size() const { return Ranges.size(); }
74
75  std::optional<T> getRangeThatContains(uint64_t Addr) const {
76    typename Collection::const_iterator It = find(Addr, Addr + 1);
77    if (It == Ranges.end())
78      return std::nullopt;
79
80    return *It;
81  }
82
83  typename Collection::const_iterator begin() const { return Ranges.begin(); }
84  typename Collection::const_iterator end() const { return Ranges.end(); }
85
86  const T &operator[](size_t i) const {
87    assert(i < Ranges.size());
88    return Ranges[i];
89  }
90
91  bool operator==(const AddressRangesBase<T> &RHS) const {
92    return Ranges == RHS.Ranges;
93  }
94
95protected:
96  typename Collection::const_iterator find(uint64_t Start, uint64_t End) const {
97    if (Start >= End)
98      return Ranges.end();
99
100    auto It =
101        std::partition_point(Ranges.begin(), Ranges.end(), [=](const T &R) {
102          return AddressRange(R).start() <= Start;
103        });
104
105    if (It == Ranges.begin())
106      return Ranges.end();
107
108    --It;
109    if (End > AddressRange(*It).end())
110      return Ranges.end();
111
112    return It;
113  }
114};
115
116/// The AddressRanges class helps normalize address range collections.
117/// This class keeps a sorted vector of AddressRange objects and can perform
118/// insertions and searches efficiently. Intersecting([100,200), [150,300))
119/// and adjacent([100,200), [200,300)) address ranges are combined during
120/// insertion.
121class AddressRanges : public AddressRangesBase<AddressRange> {
122public:
123  Collection::const_iterator insert(AddressRange Range) {
124    if (Range.empty())
125      return Ranges.end();
126
127    auto It = llvm::upper_bound(Ranges, Range);
128    auto It2 = It;
129    while (It2 != Ranges.end() && It2->start() <= Range.end())
130      ++It2;
131    if (It != It2) {
132      Range = {Range.start(), std::max(Range.end(), std::prev(It2)->end())};
133      It = Ranges.erase(It, It2);
134    }
135    if (It != Ranges.begin() && Range.start() <= std::prev(It)->end()) {
136      --It;
137      *It = {It->start(), std::max(It->end(), Range.end())};
138      return It;
139    }
140
141    return Ranges.insert(It, Range);
142  }
143};
144
145class AddressRangeValuePair {
146public:
147  operator AddressRange() const { return Range; }
148
149  AddressRange Range;
150  int64_t Value = 0;
151};
152
153inline bool operator==(const AddressRangeValuePair &LHS,
154                       const AddressRangeValuePair &RHS) {
155  return LHS.Range == RHS.Range && LHS.Value == RHS.Value;
156}
157
158/// AddressRangesMap class maps values to the address ranges.
159/// It keeps normalized address ranges and corresponding values.
160/// This class keeps a sorted vector of AddressRangeValuePair objects
161/// and can perform insertions and searches efficiently.
162/// Intersecting([100,200), [150,300)) ranges splitted into non-conflicting
163/// parts([100,200), [200,300)). Adjacent([100,200), [200,300)) address
164/// ranges are not combined during insertion.
165class AddressRangesMap : public AddressRangesBase<AddressRangeValuePair> {
166public:
167  void insert(AddressRange Range, int64_t Value) {
168    if (Range.empty())
169      return;
170
171    // Search for range which is less than or equal incoming Range.
172    auto It = std::partition_point(Ranges.begin(), Ranges.end(),
173                                   [=](const AddressRangeValuePair &R) {
174                                     return R.Range.start() <= Range.start();
175                                   });
176
177    if (It != Ranges.begin())
178      It--;
179
180    while (!Range.empty()) {
181      // Inserted range does not overlap with any range.
182      // Store it into the Ranges collection.
183      if (It == Ranges.end() || Range.end() <= It->Range.start()) {
184        Ranges.insert(It, {Range, Value});
185        return;
186      }
187
188      // Inserted range partially overlaps with current range.
189      // Store not overlapped part of inserted range.
190      if (Range.start() < It->Range.start()) {
191        It = Ranges.insert(It, {{Range.start(), It->Range.start()}, Value});
192        It++;
193        Range = {It->Range.start(), Range.end()};
194        continue;
195      }
196
197      // Inserted range fully overlaps with current range.
198      if (Range.end() <= It->Range.end())
199        return;
200
201      // Inserted range partially overlaps with current range.
202      // Remove overlapped part from the inserted range.
203      if (Range.start() < It->Range.end())
204        Range = {It->Range.end(), Range.end()};
205
206      It++;
207    }
208  }
209};
210
211} // namespace llvm
212
213#endif // LLVM_ADT_ADDRESSRANGES_H
214