include/llvm/Analysis/ProfileSummaryInfo.h

   1 //===- llvm/Analysis/ProfileSummaryInfo.h - profile summary ---*- 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 //
   9 // This file contains a pass that provides access to profile summary
  10 // information.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
  15 #define LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
  16
  17 #include "llvm/ADT/ArrayRef.h"
  18 #include "llvm/ADT/DenseMap.h"
  19 #include "llvm/ADT/SmallSet.h"
  20 #include "llvm/IR/Function.h"
  21 #include "llvm/IR/Instructions.h"
  22 #include "llvm/IR/PassManager.h"
  23 #include "llvm/IR/ProfileSummary.h"
  24 #include "llvm/IR/ValueHandle.h"
  25 #include "llvm/Pass.h"
  26 #include <memory>
  27
  28 namespace llvm {
  29 class BasicBlock;
  30 class BlockFrequencyInfo;
  31 class CallSite;
  32 class ProfileSummary;
  33 /// Analysis providing profile information.
  34 ///
  35 /// This is an immutable analysis pass that provides ability to query global
  36 /// (program-level) profile information. The main APIs are isHotCount and
  37 /// isColdCount that tells whether a given profile count is considered hot/cold
  38 /// based on the profile summary. This also provides convenience methods to
  39 /// check whether a function is hot or cold.
  40
  41 // FIXME: Provide convenience methods to determine hotness/coldness of other IR
  42 // units. This would require making this depend on BFI.
  43 class ProfileSummaryInfo {
  44 private:
  45   Module &M;
  46   std::unique_ptr<ProfileSummary> Summary;
  47   bool computeSummary();
  48   void computeThresholds();
  49   // Count thresholds to answer isHotCount and isColdCount queries.
  50   Optional<uint64_t> HotCountThreshold, ColdCountThreshold;
  51   // True if the working set size of the code is considered huge,
  52   // because the number of profile counts required to reach the hot
  53   // percentile is above a huge threshold.
  54   Optional<bool> HasHugeWorkingSetSize;
  55
  56 public:
  57   ProfileSummaryInfo(Module &M) : M(M) {}
  58   ProfileSummaryInfo(ProfileSummaryInfo &&Arg)
  59       : M(Arg.M), Summary(std::move(Arg.Summary)) {}
  60
  61   /// Returns true if profile summary is available.
  62   bool hasProfileSummary() { return computeSummary(); }
  63
  64   /// Returns true if module \c M has sample profile.
  65   bool hasSampleProfile() {
  66     return hasProfileSummary() &&
  67            Summary->getKind() == ProfileSummary::PSK_Sample;
  68   }
  69
  70   /// Returns true if module \c M has instrumentation profile.
  71   bool hasInstrumentationProfile() {
  72     return hasProfileSummary() &&
  73            Summary->getKind() == ProfileSummary::PSK_Instr;
  74   }
  75
  76   /// Returns true if module \c M has context sensitive instrumentation profile.
  77   bool hasCSInstrumentationProfile() {
  78     return hasProfileSummary() &&
  79            Summary->getKind() == ProfileSummary::PSK_CSInstr;
  80   }
  81
  82   /// Handle the invalidation of this information.
  83   ///
  84   /// When used as a result of \c ProfileSummaryAnalysis this method will be
  85   /// called when the module this was computed for changes. Since profile
  86   /// summary is immutable after it is annotated on the module, we return false
  87   /// here.
  88   bool invalidate(Module &, const PreservedAnalyses &,
  89                   ModuleAnalysisManager::Invalidator &) {
  90     return false;
  91   }
  92
  93   /// Returns the profile count for \p CallInst.
  94   Optional<uint64_t> getProfileCount(const Instruction *CallInst,
  95                                      BlockFrequencyInfo *BFI,
  96                                      bool AllowSynthetic = false);
  97   /// Returns true if the working set size of the code is considered huge.
  98   bool hasHugeWorkingSetSize();
  99   /// Returns true if \p F has hot function entry.
 100   bool isFunctionEntryHot(const Function *F);
 101   /// Returns true if \p F contains hot code.
 102   bool isFunctionHotInCallGraph(const Function *F, BlockFrequencyInfo &BFI);
 103   /// Returns true if \p F has cold function entry.
 104   bool isFunctionEntryCold(const Function *F);
 105   /// Returns true if \p F contains only cold code.
 106   bool isFunctionColdInCallGraph(const Function *F, BlockFrequencyInfo &BFI);
 107   /// Returns true if count \p C is considered hot.
 108   bool isHotCount(uint64_t C);
 109   /// Returns true if count \p C is considered cold.
 110   bool isColdCount(uint64_t C);
 111   /// Returns true if BasicBlock \p BB is considered hot.
 112   bool isHotBlock(const BasicBlock *BB, BlockFrequencyInfo *BFI);
 113   /// Returns true if BasicBlock \p BB is considered cold.
 114   bool isColdBlock(const BasicBlock *BB, BlockFrequencyInfo *BFI);
 115   /// Returns true if CallSite \p CS is considered hot.
 116   bool isHotCallSite(const CallSite &CS, BlockFrequencyInfo *BFI);
 117   /// Returns true if Callsite \p CS is considered cold.
 118   bool isColdCallSite(const CallSite &CS, BlockFrequencyInfo *BFI);
 119   /// Returns HotCountThreshold if set. Recompute HotCountThreshold
 120   /// if not set.
 121   uint64_t getOrCompHotCountThreshold();
 122   /// Returns ColdCountThreshold if set. Recompute HotCountThreshold
 123   /// if not set.
 124   uint64_t getOrCompColdCountThreshold();
 125   /// Returns HotCountThreshold if set.
 126   uint64_t getHotCountThreshold() {
 127     return HotCountThreshold ? HotCountThreshold.getValue() : 0;
 128   }
 129   /// Returns ColdCountThreshold if set.
 130   uint64_t getColdCountThreshold() {
 131     return ColdCountThreshold ? ColdCountThreshold.getValue() : 0;
 132   }
 133 };
 134
 135 /// An analysis pass based on legacy pass manager to deliver ProfileSummaryInfo.
 136 class ProfileSummaryInfoWrapperPass : public ImmutablePass {
 137   std::unique_ptr<ProfileSummaryInfo> PSI;
 138
 139 public:
 140   static char ID;
 141   ProfileSummaryInfoWrapperPass();
 142
 143   ProfileSummaryInfo &getPSI() { return *PSI; }
 144   const ProfileSummaryInfo &getPSI() const { return *PSI; }
 145
 146   bool doInitialization(Module &M) override;
 147   bool doFinalization(Module &M) override;
 148   void getAnalysisUsage(AnalysisUsage &AU) const override {
 149     AU.setPreservesAll();
 150   }
 151 };
 152
 153 /// An analysis pass based on the new PM to deliver ProfileSummaryInfo.
 154 class ProfileSummaryAnalysis
 155     : public AnalysisInfoMixin<ProfileSummaryAnalysis> {
 156 public:
 157   typedef ProfileSummaryInfo Result;
 158
 159   Result run(Module &M, ModuleAnalysisManager &);
 160
 161 private:
 162   friend AnalysisInfoMixin<ProfileSummaryAnalysis>;
 163   static AnalysisKey Key;
 164 };
 165
 166 /// Printer pass that uses \c ProfileSummaryAnalysis.
 167 class ProfileSummaryPrinterPass
 168     : public PassInfoMixin<ProfileSummaryPrinterPass> {
 169   raw_ostream &OS;
 170
 171 public:
 172   explicit ProfileSummaryPrinterPass(raw_ostream &OS) : OS(OS) {}
 173   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
 174 };
 175
 176 } // end namespace llvm
 177
 178 #endif