1//===- MachineLoopRanges.h - Ranges of machine loops -----------*- c++ -*--===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file provides the interface to the MachineLoopRanges analysis.
11//
12// Provide on-demand information about the ranges of machine instructions
13// covered by a loop.
14//
15//===----------------------------------------------------------------------===//
16
17#ifndef LLVM_CODEGEN_MACHINELOOPRANGES_H
18#define LLVM_CODEGEN_MACHINELOOPRANGES_H
19
20#include "llvm/ADT/IntervalMap.h"
21#include "llvm/CodeGen/SlotIndexes.h"
22
23namespace llvm {
24
25class MachineLoop;
26class MachineLoopInfo;
27class raw_ostream;
28
29/// MachineLoopRange - Range information for a single loop.
30class MachineLoopRange {
31  friend class MachineLoopRanges;
32
33public:
34  typedef IntervalMap<SlotIndex, unsigned, 4> Map;
35  typedef Map::Allocator Allocator;
36
37private:
38  /// The mapped loop.
39  const MachineLoop *const Loop;
40
41  /// Map intervals to a bit mask.
42  /// Bit 0 = inside loop block.
43  Map Intervals;
44
45  /// Loop area as measured by SlotIndex::distance.
46  unsigned Area;
47
48  /// Create a MachineLoopRange, only accessible to MachineLoopRanges.
49  MachineLoopRange(const MachineLoop*, Allocator&, SlotIndexes&);
50
51public:
52  /// getLoop - Return the mapped machine loop.
53  const MachineLoop *getLoop() const { return Loop; }
54
55  /// overlaps - Return true if this loop overlaps the given range of machine
56  /// inteructions.
57  bool overlaps(SlotIndex Start, SlotIndex Stop);
58
59  /// getNumber - Return the loop number. This is the same as the number of the
60  /// header block.
61  unsigned getNumber() const;
62
63  /// getArea - Return the loop area. This number is approximately proportional
64  /// to the number of instructions in the loop.
65  unsigned getArea() const { return Area; }
66
67  /// getMap - Allow public read-only access for IntervalMapOverlaps.
68  const Map &getMap() { return Intervals; }
69
70  /// print - Print loop ranges on OS.
71  void print(raw_ostream&) const;
72
73  /// byNumber - Comparator for array_pod_sort that sorts a list of
74  /// MachineLoopRange pointers by number.
75  static int byNumber(const void*, const void*);
76
77  /// byAreaDesc - Comparator for array_pod_sort that sorts a list of
78  /// MachineLoopRange pointers by descending area, then by number.
79  static int byAreaDesc(const void*, const void*);
80};
81
82raw_ostream &operator<<(raw_ostream&, const MachineLoopRange&);
83
84/// MachineLoopRanges - Analysis pass that provides on-demand per-loop range
85/// information.
86class MachineLoopRanges : public MachineFunctionPass {
87  typedef DenseMap<const MachineLoop*, MachineLoopRange*> CacheMap;
88  typedef MachineLoopRange::Allocator MapAllocator;
89
90  MapAllocator Allocator;
91  SlotIndexes *Indexes;
92  CacheMap Cache;
93
94public:
95  static char ID; // Pass identification, replacement for typeid
96
97  MachineLoopRanges() : MachineFunctionPass(ID), Indexes(0) {}
98  ~MachineLoopRanges() { releaseMemory(); }
99
100  /// getLoopRange - Return the range of loop.
101  MachineLoopRange *getLoopRange(const MachineLoop *Loop);
102
103private:
104  virtual bool runOnMachineFunction(MachineFunction&);
105  virtual void releaseMemory();
106  virtual void getAnalysisUsage(AnalysisUsage&) const;
107};
108
109
110} // end namespace llvm
111
112#endif // LLVM_CODEGEN_MACHINELOOPRANGES_H
113