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
24namespace llvm {
25
26class Triple;
27class FunctionPass;
28class ModulePass;
29class OptimizationRemarkEmitter;
30class Comdat;
31class 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.
38BasicBlock::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.
42GlobalVariable *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.
49Comdat *getOrCreateFunctionComdat(Function &F, Triple &T);
50
51// Insert GCOV profiling instrumentation
52struct 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
78ModulePass *createGCOVProfilerPass(const GCOVOptions &Options =
79 GCOVOptions::getDefault());
80
81// PGO Instrumention. Parameter IsCS indicates if this is the context senstive
82// instrumentation.
83ModulePass *createPGOInstrumentationGenLegacyPass(bool IsCS = false);
84ModulePass *
85createPGOInstrumentationUseLegacyPass(StringRef Filename = StringRef(""),
86 bool IsCS = false);
87ModulePass *createPGOInstrumentationGenCreateVarLegacyPass(
88 StringRef CSInstrName = StringRef(""));
89ModulePass *createPGOIndirectCallPromotionLegacyPass(bool InLTO = false,
90 bool SamplePGO = false);
91FunctionPass *createPGOMemOPSizeOptLegacyPass();
92
93ModulePass *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.
100namespace 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.
115CallBase &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.
121struct 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.
142ModulePass *createInstrProfilingLegacyPass(
143 const InstrProfOptions &Options = InstrProfOptions(), bool IsCS = false);
144
145ModulePass *createInstrOrderFilePass();
146
147// Insert DataFlowSanitizer (dynamic data flow analysis) instrumentation
148ModulePass *createDataFlowSanitizerLegacyPassPass(
149 const std::vector<std::string> &ABIListFiles = std::vector<std::string>());
150
151// Options for sanitizer coverage instrumentation.
152struct 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().
180static 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///
190static 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