blob: 848ee1dc0dc6013ca49999e40afc1339d0e0a042 [file] [log] [blame]
Andrew Scull5e1ddfa2018-08-14 10:06:54 +01001///===- LazyMachineBlockFrequencyInfo.h - Lazy Block Frequency -*- 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/// \file
10/// This is an alternative analysis pass to MachineBlockFrequencyInfo. The
11/// difference is that with this pass the block frequencies are not computed
12/// when the analysis pass is executed but rather when the BFI result is
13/// explicitly requested by the analysis client.
14///
15///===---------------------------------------------------------------------===//
16
17#ifndef LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H
18#define LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H
19
20#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
21#include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
22#include "llvm/CodeGen/MachineDominators.h"
23#include "llvm/CodeGen/MachineLoopInfo.h"
24
25namespace llvm {
26/// \brief This is an alternative analysis pass to MachineBlockFrequencyInfo.
27/// The difference is that with this pass, the block frequencies are not
28/// computed when the analysis pass is executed but rather when the BFI result
29/// is explicitly requested by the analysis client.
30///
31/// This works by checking querying if MBFI is available and otherwise
32/// generating MBFI on the fly. In this case the passes required for (LI, DT)
33/// are also queried before being computed on the fly.
34///
35/// Note that it is expected that we wouldn't need this functionality for the
36/// new PM since with the new PM, analyses are executed on demand.
37
38class LazyMachineBlockFrequencyInfoPass : public MachineFunctionPass {
39private:
40 /// If generated on the fly this own the instance.
41 mutable std::unique_ptr<MachineBlockFrequencyInfo> OwnedMBFI;
42
43 /// If generated on the fly this own the instance.
44 mutable std::unique_ptr<MachineLoopInfo> OwnedMLI;
45
46 /// If generated on the fly this own the instance.
47 mutable std::unique_ptr<MachineDominatorTree> OwnedMDT;
48
49 /// The function.
50 MachineFunction *MF = nullptr;
51
52 /// \brief Calculate MBFI and all other analyses that's not available and
53 /// required by BFI.
54 MachineBlockFrequencyInfo &calculateIfNotAvailable() const;
55
56public:
57 static char ID;
58
59 LazyMachineBlockFrequencyInfoPass();
60
61 /// \brief Compute and return the block frequencies.
62 MachineBlockFrequencyInfo &getBFI() { return calculateIfNotAvailable(); }
63
64 /// \brief Compute and return the block frequencies.
65 const MachineBlockFrequencyInfo &getBFI() const {
66 return calculateIfNotAvailable();
67 }
68
69 void getAnalysisUsage(AnalysisUsage &AU) const override;
70
71 bool runOnMachineFunction(MachineFunction &F) override;
72 void releaseMemory() override;
73 void print(raw_ostream &OS, const Module *M) const override;
74};
75}
76#endif