1 //===- Transforms/Instrumentation.h - Instrumentation passes ----*- 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 defines constructor functions for instrumentation passes. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_TRANSFORMS_INSTRUMENTATION_H 14 #define LLVM_TRANSFORMS_INSTRUMENTATION_H 15 16 #include "llvm/ADT/StringRef.h" 17 #include "llvm/IR/BasicBlock.h" 18 #include <cassert> 19 #include <cstdint> 20 #include <limits> 21 #include <string> 22 #include <vector> 23 24 namespace llvm { 25 26 class Triple; 27 class FunctionPass; 28 class ModulePass; 29 class OptimizationRemarkEmitter; 30 class Comdat; 31 class CallBase; 32 33 /// Instrumentation passes often insert conditional checks into entry blocks. 34 /// Call this function before splitting the entry block to move instructions 35 /// that must remain in the entry block up before the split point. Static 36 /// allocas and llvm.localescape calls, for example, must remain in the entry 37 /// block. 38 BasicBlock::iterator PrepareToSplitEntryBlock(BasicBlock &BB, 39 BasicBlock::iterator IP); 40 41 // Create a constant for Str so that we can pass it to the run-time lib. 42 GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str, 43 bool AllowMerging, 44 const char *NamePrefix = ""); 45 46 // Returns F.getComdat() if it exists. 47 // Otherwise creates a new comdat, sets F's comdat, and returns it. 48 // Returns nullptr on failure. 49 Comdat *getOrCreateFunctionComdat(Function &F, Triple &T); 50 51 // Insert GCOV profiling instrumentation 52 struct GCOVOptions { 53 static GCOVOptions getDefault(); 54 55 // Specify whether to emit .gcno files. 56 bool EmitNotes; 57 58 // Specify whether to modify the program to emit .gcda files when run. 59 bool EmitData; 60 61 // A four-byte version string. The meaning of a version string is described in 62 // gcc's gcov-io.h 63 char Version[4]; 64 65 // Add the 'noredzone' attribute to added runtime library calls. 66 bool NoRedZone; 67 68 // Use atomic profile counter increments. 69 bool Atomic = false; 70 71 // Regexes separated by a semi-colon to filter the files to instrument. 72 std::string Filter; 73 74 // Regexes separated by a semi-colon to filter the files to not instrument. 75 std::string Exclude; 76 }; 77 78 ModulePass *createGCOVProfilerPass(const GCOVOptions &Options = 79 GCOVOptions::getDefault()); 80 81 // PGO Instrumention. Parameter IsCS indicates if this is the context senstive 82 // instrumentation. 83 ModulePass *createPGOInstrumentationGenLegacyPass(bool IsCS = false); 84 ModulePass * 85 createPGOInstrumentationUseLegacyPass(StringRef Filename = StringRef(""), 86 bool IsCS = false); 87 ModulePass *createPGOInstrumentationGenCreateVarLegacyPass( 88 StringRef CSInstrName = StringRef("")); 89 ModulePass *createPGOIndirectCallPromotionLegacyPass(bool InLTO = false, 90 bool SamplePGO = false); 91 FunctionPass *createPGOMemOPSizeOptLegacyPass(); 92 93 ModulePass *createCGProfileLegacyPass(); 94 95 // The pgo-specific indirect call promotion function declared below is used by 96 // the pgo-driven indirect call promotion and sample profile passes. It's a 97 // wrapper around llvm::promoteCall, et al. that additionally computes !prof 98 // metadata. We place it in a pgo namespace so it's not confused with the 99 // generic utilities. 100 namespace pgo { 101 102 // Helper function that transforms CB (either an indirect-call instruction, or 103 // an invoke instruction , to a conditional call to F. This is like: 104 // if (Inst.CalledValue == F) 105 // F(...); 106 // else 107 // Inst(...); 108 // end 109 // TotalCount is the profile count value that the instruction executes. 110 // Count is the profile count value that F is the target function. 111 // These two values are used to update the branch weight. 112 // If \p AttachProfToDirectCall is true, a prof metadata is attached to the 113 // new direct call to contain \p Count. 114 // Returns the promoted direct call instruction. 115 CallBase &promoteIndirectCall(CallBase &CB, Function *F, uint64_t Count, 116 uint64_t TotalCount, bool AttachProfToDirectCall, 117 OptimizationRemarkEmitter *ORE); 118 } // namespace pgo 119 120 /// Options for the frontend instrumentation based profiling pass. 121 struct InstrProfOptions { 122 // Add the 'noredzone' attribute to added runtime library calls. 123 bool NoRedZone = false; 124 125 // Do counter register promotion 126 bool DoCounterPromotion = false; 127 128 // Use atomic profile counter increments. 129 bool Atomic = false; 130 131 // Use BFI to guide register promotion 132 bool UseBFIInPromotion = false; 133 134 // Name of the profile file to use as output 135 std::string InstrProfileOutput; 136 137 InstrProfOptions() = default; 138 }; 139 140 /// Insert frontend instrumentation based profiling. Parameter IsCS indicates if 141 // this is the context senstive instrumentation. 142 ModulePass *createInstrProfilingLegacyPass( 143 const InstrProfOptions &Options = InstrProfOptions(), bool IsCS = false); 144 145 ModulePass *createInstrOrderFilePass(); 146 147 // Insert DataFlowSanitizer (dynamic data flow analysis) instrumentation 148 ModulePass *createDataFlowSanitizerLegacyPassPass( 149 const std::vector<std::string> &ABIListFiles = std::vector<std::string>()); 150 151 // Options for sanitizer coverage instrumentation. 152 struct SanitizerCoverageOptions { 153 enum Type { 154 SCK_None = 0, 155 SCK_Function, 156 SCK_BB, 157 SCK_Edge 158 } CoverageType = SCK_None; 159 bool IndirectCalls = false; 160 bool TraceBB = false; 161 bool TraceCmp = false; 162 bool TraceDiv = false; 163 bool TraceGep = false; 164 bool Use8bitCounters = false; 165 bool TracePC = false; 166 bool TracePCGuard = false; 167 bool Inline8bitCounters = false; 168 bool InlineBoolFlag = false; 169 bool PCTable = false; 170 bool NoPrune = false; 171 bool StackDepth = false; 172 173 SanitizerCoverageOptions() = default; 174 }; 175 176 /// Calculate what to divide by to scale counts. 177 /// 178 /// Given the maximum count, calculate a divisor that will scale all the 179 /// weights to strictly less than std::numeric_limits<uint32_t>::max(). 180 static inline uint64_t calculateCountScale(uint64_t MaxCount) { 181 return MaxCount < std::numeric_limits<uint32_t>::max() 182 ? 1 183 : MaxCount / std::numeric_limits<uint32_t>::max() + 1; 184 } 185 186 /// Scale an individual branch count. 187 /// 188 /// Scale a 64-bit weight down to 32-bits using \c Scale. 189 /// 190 static inline uint32_t scaleBranchCount(uint64_t Count, uint64_t Scale) { 191 uint64_t Scaled = Count / Scale; 192 assert(Scaled <= std::numeric_limits<uint32_t>::max() && "overflow 32-bits"); 193 return Scaled; 194 } 195 } // end namespace llvm 196 197 #endif // LLVM_TRANSFORMS_INSTRUMENTATION_H 198
Indexes created Tue Feb 24 08:35:24 UTC 2026