| ///===- 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 |