[Alignment][NFC] Support compile time constants
[llvm-core.git] / include / llvm / CodeGen / LazyMachineBlockFrequencyInfo.h
blobca99c6c89b191f7c2a824dcdbf54bed306c16e4a
1 ///===- LazyMachineBlockFrequencyInfo.h - Lazy Block Frequency -*- 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 /// \file
9 /// This is an alternative analysis pass to MachineBlockFrequencyInfo. The
10 /// difference is that with this pass the block frequencies are not computed
11 /// when the analysis pass is executed but rather when the BFI result is
12 /// explicitly requested by the analysis client.
13 ///
14 ///===---------------------------------------------------------------------===//
16 #ifndef LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H
17 #define LLVM_ANALYSIS_LAZYMACHINEBLOCKFREQUENCYINFO_H
19 #include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
20 #include "llvm/CodeGen/MachineBranchProbabilityInfo.h"
21 #include "llvm/CodeGen/MachineDominators.h"
22 #include "llvm/CodeGen/MachineLoopInfo.h"
24 namespace llvm {
25 /// This is an alternative analysis pass to MachineBlockFrequencyInfo.
26 /// The difference is that with this pass, the block frequencies are not
27 /// computed when the analysis pass is executed but rather when the BFI result
28 /// is explicitly requested by the analysis client.
29 ///
30 /// This works by checking querying if MBFI is available and otherwise
31 /// generating MBFI on the fly. In this case the passes required for (LI, DT)
32 /// are also queried before being computed on the fly.
33 ///
34 /// Note that it is expected that we wouldn't need this functionality for the
35 /// new PM since with the new PM, analyses are executed on demand.
37 class LazyMachineBlockFrequencyInfoPass : public MachineFunctionPass {
38 private:
39 /// If generated on the fly this own the instance.
40 mutable std::unique_ptr<MachineBlockFrequencyInfo> OwnedMBFI;
42 /// If generated on the fly this own the instance.
43 mutable std::unique_ptr<MachineLoopInfo> OwnedMLI;
45 /// If generated on the fly this own the instance.
46 mutable std::unique_ptr<MachineDominatorTree> OwnedMDT;
48 /// The function.
49 MachineFunction *MF = nullptr;
51 /// Calculate MBFI and all other analyses that's not available and
52 /// required by BFI.
53 MachineBlockFrequencyInfo &calculateIfNotAvailable() const;
55 public:
56 static char ID;
58 LazyMachineBlockFrequencyInfoPass();
60 /// Compute and return the block frequencies.
61 MachineBlockFrequencyInfo &getBFI() { return calculateIfNotAvailable(); }
63 /// Compute and return the block frequencies.
64 const MachineBlockFrequencyInfo &getBFI() const {
65 return calculateIfNotAvailable();
68 void getAnalysisUsage(AnalysisUsage &AU) const override;
70 bool runOnMachineFunction(MachineFunction &F) override;
71 void releaseMemory() override;
72 void print(raw_ostream &OS, const Module *M) const override;
75 #endif