1//===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- 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// Loops should be simplified before this analysis.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
14#define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
15
16#include "llvm/ADT/Optional.h"
17#include "llvm/CodeGen/MachineFunctionPass.h"
18#include "llvm/Support/BlockFrequency.h"
19#include <cstdint>
20#include <memory>
21
22namespace llvm {
23
24template <class BlockT> class BlockFrequencyInfoImpl;
25class MachineBasicBlock;
26class MachineBranchProbabilityInfo;
27class MachineFunction;
28class MachineLoopInfo;
29class raw_ostream;
30
31/// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation
32/// to estimate machine basic block frequencies.
33class MachineBlockFrequencyInfo : public MachineFunctionPass {
34  using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>;
35  std::unique_ptr<ImplType> MBFI;
36
37public:
38  static char ID;
39
40  MachineBlockFrequencyInfo();
41  explicit MachineBlockFrequencyInfo(MachineFunction &F,
42                                     MachineBranchProbabilityInfo &MBPI,
43                                     MachineLoopInfo &MLI);
44  ~MachineBlockFrequencyInfo() override;
45
46  void getAnalysisUsage(AnalysisUsage &AU) const override;
47
48  bool runOnMachineFunction(MachineFunction &F) override;
49
50  /// calculate - compute block frequency info for the given function.
51  void calculate(const MachineFunction &F,
52                 const MachineBranchProbabilityInfo &MBPI,
53                 const MachineLoopInfo &MLI);
54
55  void releaseMemory() override;
56
57  /// getblockFreq - Return block frequency. Return 0 if we don't have the
58  /// information. Please note that initial frequency is equal to 1024. It means
59  /// that we should not rely on the value itself, but only on the comparison to
60  /// the other block frequencies. We do this to avoid using of floating points.
61  ///
62  BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
63
64  Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
65  Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
66
67  bool isIrrLoopHeader(const MachineBasicBlock *MBB);
68
69  const MachineFunction *getFunction() const;
70  const MachineBranchProbabilityInfo *getMBPI() const;
71  void view(const Twine &Name, bool isSimple = true) const;
72
73  // Print the block frequency Freq to OS using the current functions entry
74  // frequency to convert freq into a relative decimal form.
75  raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
76
77  // Convenience method that attempts to look up the frequency associated with
78  // BB and print it to OS.
79  raw_ostream &printBlockFreq(raw_ostream &OS,
80                              const MachineBasicBlock *MBB) const;
81
82  uint64_t getEntryFreq() const;
83};
84
85} // end namespace llvm
86
87#endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
88