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      1 //===- llvm/Analysis/ProfileSummaryInfo.h - profile summary ---*- 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 //
     10 // This file contains a pass that provides access to profile summary
     11 // information.
     12 //
     13 //===----------------------------------------------------------------------===//
     14 
     15 #ifndef LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
     16 #define LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
     17 
     18 #include "llvm/ADT/ArrayRef.h"
     19 #include "llvm/ADT/DenseMap.h"
     20 #include "llvm/ADT/SmallSet.h"
     21 #include "llvm/IR/Function.h"
     22 #include "llvm/IR/Instructions.h"
     23 #include "llvm/IR/PassManager.h"
     24 #include "llvm/IR/ProfileSummary.h"
     25 #include "llvm/IR/ValueHandle.h"
     26 #include "llvm/Pass.h"
     27 #include <memory>
     28 
     29 namespace llvm {
     30 class ProfileSummary;
     31 /// \brief Analysis providing profile information.
     32 ///
     33 /// This is an immutable analysis pass that provides ability to query global
     34 /// (program-level) profile information. The main APIs are isHotCount and
     35 /// isColdCount that tells whether a given profile count is considered hot/cold
     36 /// based on the profile summary. This also provides convenience methods to
     37 /// check whether a function is hot or cold.
     38 
     39 // FIXME: Provide convenience methods to determine hotness/coldness of other IR
     40 // units. This would require making this depend on BFI.
     41 class ProfileSummaryInfo {
     42 private:
     43   Module &M;
     44   std::unique_ptr<ProfileSummary> Summary;
     45   void computeSummary();
     46   void computeThresholds();
     47   // Count thresholds to answer isHotCount and isColdCount queries.
     48   Optional<uint64_t> HotCountThreshold, ColdCountThreshold;
     49 
     50 public:
     51   ProfileSummaryInfo(Module &M) : M(M) {}
     52   ProfileSummaryInfo(ProfileSummaryInfo &&Arg)
     53       : M(Arg.M), Summary(std::move(Arg.Summary)) {}
     54   /// \brief Returns true if \p F is a hot function.
     55   bool isHotFunction(const Function *F);
     56   /// \brief Returns true if \p F is a cold function.
     57   bool isColdFunction(const Function *F);
     58   /// \brief Returns true if count \p C is considered hot.
     59   bool isHotCount(uint64_t C);
     60   /// \brief Returns true if count \p C is considered cold.
     61   bool isColdCount(uint64_t C);
     62 };
     63 
     64 /// An analysis pass based on legacy pass manager to deliver ProfileSummaryInfo.
     65 class ProfileSummaryInfoWrapperPass : public ImmutablePass {
     66   std::unique_ptr<ProfileSummaryInfo> PSI;
     67 
     68 public:
     69   static char ID;
     70   ProfileSummaryInfoWrapperPass();
     71 
     72   ProfileSummaryInfo *getPSI(Module &M);
     73   void getAnalysisUsage(AnalysisUsage &AU) const override {
     74     AU.setPreservesAll();
     75   }
     76 };
     77 
     78 /// An analysis pass based on the new PM to deliver ProfileSummaryInfo.
     79 class ProfileSummaryAnalysis
     80     : public AnalysisInfoMixin<ProfileSummaryAnalysis> {
     81 public:
     82   typedef ProfileSummaryInfo Result;
     83 
     84   ProfileSummaryAnalysis() {}
     85   ProfileSummaryAnalysis(const ProfileSummaryAnalysis &Arg) {}
     86   ProfileSummaryAnalysis(ProfileSummaryAnalysis &&Arg) {}
     87   ProfileSummaryAnalysis &operator=(const ProfileSummaryAnalysis &RHS) {
     88     return *this;
     89   }
     90   ProfileSummaryAnalysis &operator=(ProfileSummaryAnalysis &&RHS) {
     91     return *this;
     92   }
     93 
     94   Result run(Module &M, ModuleAnalysisManager &);
     95 
     96 private:
     97   friend AnalysisInfoMixin<ProfileSummaryAnalysis>;
     98   static char PassID;
     99 };
    100 
    101 /// \brief Printer pass that uses \c ProfileSummaryAnalysis.
    102 class ProfileSummaryPrinterPass
    103     : public PassInfoMixin<ProfileSummaryPrinterPass> {
    104   raw_ostream &OS;
    105 
    106 public:
    107   explicit ProfileSummaryPrinterPass(raw_ostream &OS) : OS(OS) {}
    108   PreservedAnalyses run(Module &M, AnalysisManager<Module> &AM);
    109 };
    110 
    111 } // end namespace llvm
    112 
    113 #endif
    114