LLVM  10.0.0svn
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,
43  std::function<const TargetLibraryInfo &(Function &F)> GetTLI);
44 
45 private:
46  InstrProfOptions Options;
47  Module *M;
48  Triple TT;
49  std::function<const TargetLibraryInfo &(Function &F)> GetTLI;
50  struct PerFunctionProfileData {
51  uint32_t NumValueSites[IPVK_Last + 1];
52  GlobalVariable *RegionCounters = nullptr;
53  GlobalVariable *DataVar = nullptr;
54 
55  PerFunctionProfileData() {
56  memset(NumValueSites, 0, sizeof(uint32_t) * (IPVK_Last + 1));
57  }
58  };
60  std::vector<GlobalValue *> UsedVars;
61  std::vector<GlobalVariable *> ReferencedNames;
62  GlobalVariable *NamesVar;
63  size_t NamesSize;
64 
65  // Is this lowering for the context-sensitive instrumentation.
66  bool IsCS;
67 
68  // vector of counter load/store pairs to be register promoted.
69  std::vector<LoadStorePair> PromotionCandidates;
70 
71  // The start value of precise value profile range for memory intrinsic sizes.
72  int64_t MemOPSizeRangeStart;
73  // The end value of precise value profile range for memory intrinsic sizes.
74  int64_t MemOPSizeRangeLast;
75 
76  int64_t TotalCountersPromoted = 0;
77 
78  /// Lower instrumentation intrinsics in the function. Returns true if there
79  /// any lowering.
80  bool lowerIntrinsics(Function *F);
81 
82  /// Register-promote counter loads and stores in loops.
83  void promoteCounterLoadStores(Function *F);
84 
85  /// Returns true if profile counter update register promotion is enabled.
86  bool isCounterPromotionEnabled() const;
87 
88  /// Count the number of instrumented value sites for the function.
89  void computeNumValueSiteCounts(InstrProfValueProfileInst *Ins);
90 
91  /// Replace instrprof_value_profile with a call to runtime library.
92  void lowerValueProfileInst(InstrProfValueProfileInst *Ins);
93 
94  /// Replace instrprof_increment with an increment of the appropriate value.
95  void lowerIncrement(InstrProfIncrementInst *Inc);
96 
97  /// Force emitting of name vars for unused functions.
98  void lowerCoverageData(GlobalVariable *CoverageNamesVar);
99 
100  /// Get the region counters for an increment, creating them if necessary.
101  ///
102  /// If the counter array doesn't yet exist, the profile data variables
103  /// referring to them will also be created.
104  GlobalVariable *getOrCreateRegionCounters(InstrProfIncrementInst *Inc);
105 
106  /// Emit the section with compressed function names.
107  void emitNameData();
108 
109  /// Emit value nodes section for value profiling.
110  void emitVNodes();
111 
112  /// Emit runtime registration functions for each profile data variable.
113  void emitRegistration();
114 
115  /// Emit the necessary plumbing to pull in the runtime initialization.
116  /// Returns true if a change was made.
117  bool emitRuntimeHook();
118 
119  /// Add uses of our data variables and runtime hook.
120  void emitUses();
121 
122  /// Create a static initializer for our data, on platforms that need it,
123  /// and for any profile output file that was specified.
124  void emitInitialization();
125 };
126 
127 } // end namespace llvm
128 
129 #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:66
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:373
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:154
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.
print Print MemDeps of function
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.