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_INSTRUMENTATION_INSTRPROFILING_H
14#define LLVM_TRANSFORMS_INSTRUMENTATION_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"
20#include "llvm/ProfileData/InstrProf.h"
21#include "llvm/Transforms/Instrumentation.h"
22#include <cstddef>
23#include <cstdint>
24#include <cstring>
25#include <vector>
26
27namespace llvm {
28
29class TargetLibraryInfo;
30using 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.
35class InstrProfiling : public PassInfoMixin<InstrProfiling> {
36public:
37 InstrProfiling() : IsCS(false) {}
38 InstrProfiling(const InstrProfOptions &Options, bool IsCS = false)
39 : Options(Options), IsCS(IsCS) {}
40
41 PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
42 bool run(Module &M,
43 std::function<const TargetLibraryInfo &(Function &F)> GetTLI);
44
45private:
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 };
59 DenseMap<GlobalVariable *, PerFunctionProfileData> ProfileDataMap;
60 std::vector<GlobalValue *> CompilerUsedVars;
61 std::vector<GlobalValue *> UsedVars;
62 std::vector<GlobalVariable *> ReferencedNames;
63 GlobalVariable *NamesVar;
64 size_t NamesSize;
65
66 // Is this lowering for the context-sensitive instrumentation.
67 bool IsCS;
68
69 // vector of counter load/store pairs to be register promoted.
70 std::vector<LoadStorePair> PromotionCandidates;
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 relocating counters at runtime is enabled.
82 bool isRuntimeCounterRelocationEnabled() const;
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_INSTRUMENTATION_INSTRPROFILING_H
129