aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm12/include/llvm/CodeGen/LazyMachineBlockFrequencyInfo.h
blob: b16e88eaa52a48a45444a8973c2ca60bd7cdb243 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
#pragma once

#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif

///===- LazyMachineBlockFrequencyInfo.h - Lazy Block Frequency -*- C++ -*--===//
///
/// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
/// See https://llvm.org/LICENSE.txt for license information.
/// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
///
///===---------------------------------------------------------------------===//
/// \file
/// This is an alternative analysis pass to MachineBlockFrequencyInfo.  The
/// difference is that with this pass the block frequencies are not computed
/// when the analysis pass is executed but rather when the BFI result is
/// explicitly requested by the analysis client.
///
///===---------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H
#define LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H

#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineLoopInfo.h"

namespace llvm {
/// This is an alternative analysis pass to MachineBlockFrequencyInfo.
/// The difference is that with this pass, the block frequencies are not
/// computed when the analysis pass is executed but rather when the BFI result
/// is explicitly requested by the analysis client.
///
/// This works by checking querying if MBFI is available and otherwise
/// generating MBFI on the fly.  In this case the passes required for (LI, DT)
/// are also queried before being computed on the fly.
///
/// Note that it is expected that we wouldn't need this functionality for the
/// new PM since with the new PM, analyses are executed on demand.

class LazyMachineBlockFrequencyInfoPass : public MachineFunctionPass {
private:
  /// If generated on the fly this own the instance.
  mutable std::unique_ptr<MachineBlockFrequencyInfo> OwnedMBFI;

  /// If generated on the fly this own the instance.
  mutable std::unique_ptr<MachineLoopInfo> OwnedMLI;

  /// If generated on the fly this own the instance.
  mutable std::unique_ptr<MachineDominatorTree> OwnedMDT;

  /// The function.
  MachineFunction *MF = nullptr;

  /// Calculate MBFI and all other analyses that's not available and
  /// required by BFI.
  MachineBlockFrequencyInfo &calculateIfNotAvailable() const;

public:
  static char ID;

  LazyMachineBlockFrequencyInfoPass();

  /// Compute and return the block frequencies.
  MachineBlockFrequencyInfo &getBFI() { return calculateIfNotAvailable(); }

  /// Compute and return the block frequencies.
  const MachineBlockFrequencyInfo &getBFI() const {
    return calculateIfNotAvailable();
  }

  void getAnalysisUsage(AnalysisUsage &AU) const override;

  bool runOnMachineFunction(MachineFunction &F) override;
  void releaseMemory() override;
  void print(raw_ostream &OS, const Module *M) const override;
};
}
#endif

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif