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      1 //===- Transforms/InstrProfiling.h - Instrumentation passes -----*- 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 /// \file
     10 /// This file provides the interface for LLVM's PGO Instrumentation lowering
     11 /// pass.
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_TRANSFORMS_INSTRPROFILING_H
     15 #define LLVM_TRANSFORMS_INSTRPROFILING_H
     16 
     17 #include "llvm/ADT/DenseMap.h"
     18 #include "llvm/ADT/StringRef.h"
     19 #include "llvm/IR/IntrinsicInst.h"
     20 #include "llvm/IR/PassManager.h"
     21 #include "llvm/ProfileData/InstrProf.h"
     22 #include "llvm/Transforms/Instrumentation.h"
     23 #include <cstddef>
     24 #include <cstdint>
     25 #include <cstring>
     26 #include <vector>
     27 
     28 namespace llvm {
     29 
     30 class TargetLibraryInfo;
     31 using LoadStorePair = std::pair<Instruction *, Instruction *>;
     32 
     33 /// Instrumentation based profiling lowering pass. This pass lowers
     34 /// the profile instrumented code generated by FE or the IR based
     35 /// instrumentation pass.
     36 class InstrProfiling : public PassInfoMixin<InstrProfiling> {
     37 public:
     38   InstrProfiling() = default;
     39   InstrProfiling(const InstrProfOptions &Options) : Options(Options) {}
     40 
     41   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
     42   bool run(Module &M, const TargetLibraryInfo &TLI);
     43 
     44 private:
     45   InstrProfOptions Options;
     46   Module *M;
     47   Triple TT;
     48   const TargetLibraryInfo *TLI;
     49   struct PerFunctionProfileData {
     50     uint32_t NumValueSites[IPVK_Last + 1];
     51     GlobalVariable *RegionCounters = nullptr;
     52     GlobalVariable *DataVar = nullptr;
     53 
     54     PerFunctionProfileData() {
     55       memset(NumValueSites, 0, sizeof(uint32_t) * (IPVK_Last + 1));
     56     }
     57   };
     58   DenseMap<GlobalVariable *, PerFunctionProfileData> ProfileDataMap;
     59   std::vector<GlobalValue *> UsedVars;
     60   std::vector<GlobalVariable *> ReferencedNames;
     61   GlobalVariable *NamesVar;
     62   size_t NamesSize;
     63 
     64   // vector of counter load/store pairs to be register promoted.
     65   std::vector<LoadStorePair> PromotionCandidates;
     66 
     67   // The start value of precise value profile range for memory intrinsic sizes.
     68   int64_t MemOPSizeRangeStart;
     69   // The end value of precise value profile range for memory intrinsic sizes.
     70   int64_t MemOPSizeRangeLast;
     71 
     72   int64_t TotalCountersPromoted = 0;
     73 
     74   /// Lower instrumentation intrinsics in the function. Returns true if there
     75   /// any lowering.
     76   bool lowerIntrinsics(Function *F);
     77 
     78   /// Register-promote counter loads and stores in loops.
     79   void promoteCounterLoadStores(Function *F);
     80 
     81   /// Returns true if profile counter update register promotion is enabled.
     82   bool isCounterPromotionEnabled() const;
     83 
     84   /// Count the number of instrumented value sites for the function.
     85   void computeNumValueSiteCounts(InstrProfValueProfileInst *Ins);
     86 
     87   /// Replace instrprof_value_profile with a call to runtime library.
     88   void lowerValueProfileInst(InstrProfValueProfileInst *Ins);
     89 
     90   /// Replace instrprof_increment with an increment of the appropriate value.
     91   void lowerIncrement(InstrProfIncrementInst *Inc);
     92 
     93   /// Force emitting of name vars for unused functions.
     94   void lowerCoverageData(GlobalVariable *CoverageNamesVar);
     95 
     96   /// Get the region counters for an increment, creating them if necessary.
     97   ///
     98   /// If the counter array doesn't yet exist, the profile data variables
     99   /// referring to them will also be created.
    100   GlobalVariable *getOrCreateRegionCounters(InstrProfIncrementInst *Inc);
    101 
    102   /// Emit the section with compressed function names.
    103   void emitNameData();
    104 
    105   /// Emit value nodes section for value profiling.
    106   void emitVNodes();
    107 
    108   /// Emit runtime registration functions for each profile data variable.
    109   void emitRegistration();
    110 
    111   /// Emit the necessary plumbing to pull in the runtime initialization.
    112   void emitRuntimeHook();
    113 
    114   /// Add uses of our data variables and runtime hook.
    115   void emitUses();
    116 
    117   /// Create a static initializer for our data, on platforms that need it,
    118   /// and for any profile output file that was specified.
    119   void emitInitialization();
    120 };
    121 
    122 } // end namespace llvm
    123 
    124 #endif // LLVM_TRANSFORMS_INSTRPROFILING_H
    125