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   /// Handle the invalidation of this information.
  77   ///
  78   /// When used as a result of \c ProfileSummaryAnalysis this method will be
  79   /// called when the module this was computed for changes. Since profile
  80   /// summary is immutable after it is annotated on the module, we return false
  81   /// here.
  82   bool invalidate(Module &, const PreservedAnalyses &,
  83                   ModuleAnalysisManager::Invalidator &) {
  84     return false;
  85   }
  86
  87   /// Returns the profile count for \p CallInst.
  88   Optional<uint64_t> getProfileCount(const Instruction *CallInst,
  89                                      BlockFrequencyInfo *BFI);
  90   /// Returns true if the working set size of the code is considered huge.
  91   bool hasHugeWorkingSetSize();
  92   /// Returns true if \p F has hot function entry.
  93   bool isFunctionEntryHot(const Function *F);
  94   /// Returns true if \p F contains hot code.
  95   bool isFunctionHotInCallGraph(const Function *F, BlockFrequencyInfo &BFI);
  96   /// Returns true if \p F has cold function entry.
  97   bool isFunctionEntryCold(const Function *F);
  98   /// Returns true if \p F contains only cold code.
  99   bool isFunctionColdInCallGraph(const Function *F, BlockFrequencyInfo &BFI);
 100   /// Returns true if count \p C is considered hot.
 101   bool isHotCount(uint64_t C);
 102   /// Returns true if count \p C is considered cold.
 103   bool isColdCount(uint64_t C);
 104   /// Returns true if BasicBlock \p BB is considered hot.
 105   bool isHotBlock(const BasicBlock *BB, BlockFrequencyInfo *BFI);
 106   /// Returns true if BasicBlock \p BB is considered cold.
 107   bool isColdBlock(const BasicBlock *BB, BlockFrequencyInfo *BFI);
 108   /// Returns true if CallSite \p CS is considered hot.
 109   bool isHotCallSite(const CallSite &CS, BlockFrequencyInfo *BFI);
 110   /// Returns true if Callsite \p CS is considered cold.
 111   bool isColdCallSite(const CallSite &CS, BlockFrequencyInfo *BFI);
 112   /// Returns HotCountThreshold if set. Recompute HotCountThreshold
 113   /// if not set.
 114   uint64_t getOrCompHotCountThreshold();
 115   /// Returns ColdCountThreshold if set. Recompute HotCountThreshold
 116   /// if not set.
 117   uint64_t getOrCompColdCountThreshold();
 118   /// Returns HotCountThreshold if set.
 119   uint64_t getHotCountThreshold() {
 120     return HotCountThreshold ? HotCountThreshold.getValue() : 0;
 121   }
 122   /// Returns ColdCountThreshold if set.
 123   uint64_t getColdCountThreshold() {
 124     return ColdCountThreshold ? ColdCountThreshold.getValue() : 0;
 125   }
 126 };
 127
 128 /// An analysis pass based on legacy pass manager to deliver ProfileSummaryInfo.
 129 class ProfileSummaryInfoWrapperPass : public ImmutablePass {
 130   std::unique_ptr<ProfileSummaryInfo> PSI;
 131
 132 public:
 133   static char ID;
 134   ProfileSummaryInfoWrapperPass();
 135
 136   ProfileSummaryInfo &getPSI() { return *PSI; }
 137   const ProfileSummaryInfo &getPSI() const { return *PSI; }
 138
 139   bool doInitialization(Module &M) override;
 140   bool doFinalization(Module &M) override;
 141   void getAnalysisUsage(AnalysisUsage &AU) const override {
 142     AU.setPreservesAll();
 143   }
 144 };
 145
 146 /// An analysis pass based on the new PM to deliver ProfileSummaryInfo.
 147 class ProfileSummaryAnalysis
 148     : public AnalysisInfoMixin<ProfileSummaryAnalysis> {
 149 public:
 150   typedef ProfileSummaryInfo Result;
 151
 152   Result run(Module &M, ModuleAnalysisManager &);
 153
 154 private:
 155   friend AnalysisInfoMixin<ProfileSummaryAnalysis>;
 156   static AnalysisKey Key;
 157 };
 158
 159 /// Printer pass that uses \c ProfileSummaryAnalysis.
 160 class ProfileSummaryPrinterPass
 161     : public PassInfoMixin<ProfileSummaryPrinterPass> {
 162   raw_ostream &OS;
 163
 164 public:
 165   explicit ProfileSummaryPrinterPass(raw_ostream &OS) : OS(OS) {}
 166   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
 167 };
 168
 169 } // end namespace llvm
 170
 171 #endif