LLVM  9.0.0svn
InstrProfiling.h
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1 //===- Transforms/Instrumentation/InstrProfiling.h --------------*- 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 /// \file
9 /// This file provides the interface for LLVM's PGO Instrumentation lowering
10 /// pass.
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_TRANSFORMS_INSTRPROFILING_H
14 #define LLVM_TRANSFORMS_INSTRPROFILING_H
15 
16 #include "llvm/ADT/DenseMap.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/IR/IntrinsicInst.h"
19 #include "llvm/IR/PassManager.h"
22 #include <cstddef>
23 #include <cstdint>
24 #include <cstring>
25 #include <vector>
26 
27 namespace llvm {
28 
29 class TargetLibraryInfo;
30 using LoadStorePair = std::pair<Instruction *, Instruction *>;
31 
32 /// Instrumentation based profiling lowering pass. This pass lowers
33 /// the profile instrumented code generated by FE or the IR based
34 /// instrumentation pass.
35 class InstrProfiling : public PassInfoMixin<InstrProfiling> {
36 public:
37  InstrProfiling() : IsCS(false) {}
38  InstrProfiling(const InstrProfOptions &Options, bool IsCS = false)
39  : Options(Options), IsCS(IsCS) {}
40 
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  };
59  std::vector<GlobalValue *> UsedVars;
60  std::vector<GlobalVariable *> ReferencedNames;
61  GlobalVariable *NamesVar;
62  size_t NamesSize;
63 
64  // Is this lowering for the context-sensitive instrumentation.
65  bool IsCS;
66 
67  // vector of counter load/store pairs to be register promoted.
68  std::vector<LoadStorePair> PromotionCandidates;
69 
70  // The start value of precise value profile range for memory intrinsic sizes.
71  int64_t MemOPSizeRangeStart;
72  // The end value of precise value profile range for memory intrinsic sizes.
73  int64_t MemOPSizeRangeLast;
74 
75  int64_t TotalCountersPromoted = 0;
76 
77  /// Lower instrumentation intrinsics in the function. Returns true if there
78  /// any lowering.
79  bool lowerIntrinsics(Function *F);
80 
81  /// Register-promote counter loads and stores in loops.
82  void promoteCounterLoadStores(Function *F);
83 
84  /// Returns true if profile counter update register promotion is enabled.
85  bool isCounterPromotionEnabled() const;
86 
87  /// Count the number of instrumented value sites for the function.
88  void computeNumValueSiteCounts(InstrProfValueProfileInst *Ins);
89 
90  /// Replace instrprof_value_profile with a call to runtime library.
91  void lowerValueProfileInst(InstrProfValueProfileInst *Ins);
92 
93  /// Replace instrprof_increment with an increment of the appropriate value.
94  void lowerIncrement(InstrProfIncrementInst *Inc);
95 
96  /// Force emitting of name vars for unused functions.
97  void lowerCoverageData(GlobalVariable *CoverageNamesVar);
98 
99  /// Get the region counters for an increment, creating them if necessary.
100  ///
101  /// If the counter array doesn't yet exist, the profile data variables
102  /// referring to them will also be created.
103  GlobalVariable *getOrCreateRegionCounters(InstrProfIncrementInst *Inc);
104 
105  /// Emit the section with compressed function names.
106  void emitNameData();
107 
108  /// Emit value nodes section for value profiling.
109  void emitVNodes();
110 
111  /// Emit runtime registration functions for each profile data variable.
112  void emitRegistration();
113 
114  /// Emit the necessary plumbing to pull in the runtime initialization.
115  /// Returns true if a change was made.
116  bool emitRuntimeHook();
117 
118  /// Add uses of our data variables and runtime hook.
119  void emitUses();
120 
121  /// Create a static initializer for our data, on platforms that need it,
122  /// and for any profile output file that was specified.
123  void emitInitialization();
124 };
125 
126 } // end namespace llvm
127 
128 #endif // LLVM_TRANSFORMS_INSTRPROFILING_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:65
F(f)
std::pair< Instruction *, Instruction * > LoadStorePair
Instrumentation based profiling lowering pass.
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:372
InstrProfiling(const InstrProfOptions &Options, bool IsCS=false)
PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM)
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:153
Triple - Helper class for working with autoconf configuration names.
Definition: Triple.h:43
Provides information about what library functions are available for the current target.
Options for the frontend instrumentation based profiling pass.
This represents the llvm.instrprof_increment intrinsic.
A container for analyses that lazily runs them and caches their results.
This header defines various interfaces for pass management in LLVM.
This represents the llvm.instrprof_value_profile intrinsic.