1 //=-- InstrProf.cpp - Instrumented profiling format support -----------------=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains support for clang's instrumentation based PGO and
13 //===----------------------------------------------------------------------===//
15 #include "llvm/IR/Constants.h"
16 #include "llvm/IR/Function.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/IR/GlobalVariable.h"
19 #include "llvm/ProfileData/InstrProf.h"
20 #include "llvm/Support/ErrorHandling.h"
21 #include "llvm/Support/ManagedStatic.h"
26 class InstrProfErrorCategoryType : public std::error_category {
27 const char *name() const LLVM_NOEXCEPT override { return "llvm.instrprof"; }
28 std::string message(int IE) const override {
29 instrprof_error E = static_cast<instrprof_error>(IE);
31 case instrprof_error::success:
33 case instrprof_error::eof:
35 case instrprof_error::bad_magic:
36 return "Invalid profile data (bad magic)";
37 case instrprof_error::bad_header:
38 return "Invalid profile data (file header is corrupt)";
39 case instrprof_error::unsupported_version:
40 return "Unsupported profiling format version";
41 case instrprof_error::unsupported_hash_type:
42 return "Unsupported profiling hash";
43 case instrprof_error::too_large:
44 return "Too much profile data";
45 case instrprof_error::truncated:
46 return "Truncated profile data";
47 case instrprof_error::malformed:
48 return "Malformed profile data";
49 case instrprof_error::unknown_function:
50 return "No profile data available for function";
51 case instrprof_error::hash_mismatch:
52 return "Function hash mismatch";
53 case instrprof_error::count_mismatch:
54 return "Function count mismatch";
55 case instrprof_error::counter_overflow:
56 return "Counter overflow";
57 case instrprof_error::value_site_count_mismatch:
58 return "Function's value site counts mismatch";
60 llvm_unreachable("A value of instrprof_error has no message.");
65 static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
67 const std::error_category &llvm::instrprof_category() {
68 return *ErrorCategory;
73 std::string getPGOFuncName(StringRef RawFuncName,
74 GlobalValue::LinkageTypes Linkage,
77 // Function names may be prefixed with a binary '1' to indicate
78 // that the backend should not modify the symbols due to any platform
79 // naming convention. Do not include that '1' in the PGO profile name.
80 if (RawFuncName[0] == '\1')
81 RawFuncName = RawFuncName.substr(1);
83 std::string FuncName = RawFuncName;
84 if (llvm::GlobalValue::isLocalLinkage(Linkage)) {
85 // For local symbols, prepend the main file name to distinguish them.
86 // Do not include the full path in the file name since there's no guarantee
87 // that it will stay the same, e.g., if the files are checked out from
88 // version control in different locations.
90 FuncName = FuncName.insert(0, "<unknown>:");
92 FuncName = FuncName.insert(0, FileName.str() + ":");
97 std::string getPGOFuncName(const Function &F) {
98 return getPGOFuncName(F.getName(), F.getLinkage(), F.getParent()->getName());
101 GlobalVariable *createPGOFuncNameVar(Module &M,
102 GlobalValue::LinkageTypes Linkage,
103 StringRef FuncName) {
105 // We generally want to match the function's linkage, but available_externally
106 // and extern_weak both have the wrong semantics, and anything that doesn't
107 // need to link across compilation units doesn't need to be visible at all.
108 if (Linkage == GlobalValue::ExternalWeakLinkage)
109 Linkage = GlobalValue::LinkOnceAnyLinkage;
110 else if (Linkage == GlobalValue::AvailableExternallyLinkage)
111 Linkage = GlobalValue::LinkOnceODRLinkage;
112 else if (Linkage == GlobalValue::InternalLinkage ||
113 Linkage == GlobalValue::ExternalLinkage)
114 Linkage = GlobalValue::PrivateLinkage;
116 auto *Value = ConstantDataArray::getString(M.getContext(), FuncName, false);
118 new GlobalVariable(M, Value->getType(), true, Linkage, Value,
119 Twine(getInstrProfNameVarPrefix()) + FuncName);
121 // Hide the symbol so that we correctly get a copy for each executable.
122 if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
123 FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
128 GlobalVariable *createPGOFuncNameVar(Function &F, StringRef FuncName) {
129 return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), FuncName);