1 //===-- ImportedFunctionsInliningStats.cpp ----------------------*- 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 // Generating inliner statistics for imported functions, mostly useful for 9 // ThinLTO. 10 //===----------------------------------------------------------------------===// 11 12 #include "llvm/Analysis/Utils/ImportedFunctionsInliningStatistics.h" 13 #include "llvm/ADT/STLExtras.h" 14 #include "llvm/IR/Function.h" 15 #include "llvm/IR/Module.h" 16 #include "llvm/Support/CommandLine.h" 17 #include "llvm/Support/Debug.h" 18 #include "llvm/Support/raw_ostream.h" 19 #include <iomanip> 20 #include <sstream> 21 #include <string> 22 23 using namespace llvm; 24 25 namespace llvm { 26 cl::opt<InlinerFunctionImportStatsOpts> InlinerFunctionImportStats( 27 "inliner-function-import-stats", 28 cl::init(InlinerFunctionImportStatsOpts::No), 29 cl::values(clEnumValN(InlinerFunctionImportStatsOpts::Basic, "basic", 30 "basic statistics"), 31 clEnumValN(InlinerFunctionImportStatsOpts::Verbose, "verbose", 32 "printing of statistics for each inlined function")), 33 cl::Hidden, cl::desc("Enable inliner stats for imported functions")); 34 } // namespace llvm 35 36 ImportedFunctionsInliningStatistics::InlineGraphNode & 37 ImportedFunctionsInliningStatistics::createInlineGraphNode(const Function &F) { 38 39 auto &ValueLookup = NodesMap[F.getName()]; 40 if (!ValueLookup) { 41 ValueLookup = std::make_unique<InlineGraphNode>(); 42 ValueLookup->Imported = F.hasMetadata("thinlto_src_module"); 43 } 44 return *ValueLookup; 45 } 46 47 void ImportedFunctionsInliningStatistics::recordInline(const Function &Caller, 48 const Function &Callee) { 49 50 InlineGraphNode &CallerNode = createInlineGraphNode(Caller); 51 InlineGraphNode &CalleeNode = createInlineGraphNode(Callee); 52 CalleeNode.NumberOfInlines++; 53 54 if (!CallerNode.Imported && !CalleeNode.Imported) { 55 // Direct inline from not imported callee to not imported caller, so we 56 // don't have to add this to graph. It might be very helpful if you wanna 57 // get the inliner statistics in compile step where there are no imported 58 // functions. In this case the graph would be empty. 59 CalleeNode.NumberOfRealInlines++; 60 return; 61 } 62 63 CallerNode.InlinedCallees.push_back(&CalleeNode); 64 if (!CallerNode.Imported) { 65 // We could avoid second lookup, but it would make the code ultra ugly. 66 auto It = NodesMap.find(Caller.getName()); 67 assert(It != NodesMap.end() && "The node should be already there."); 68 // Save Caller as a starting node for traversal. The string has to be one 69 // from map because Caller can disappear (and function name with it). 70 NonImportedCallers.push_back(It->first()); 71 } 72 } 73 74 void ImportedFunctionsInliningStatistics::setModuleInfo(const Module &M) { 75 ModuleName = M.getName(); 76 for (const auto &F : M.functions()) { 77 if (F.isDeclaration()) 78 continue; 79 AllFunctions++; 80 ImportedFunctions += int(F.hasMetadata("thinlto_src_module")); 81 } 82 } 83 static std::string getStatString(const char *Msg, int32_t Fraction, int32_t All, 84 const char *PercentageOfMsg, 85 bool LineEnd = true) { 86 double Result = 0; 87 if (All != 0) 88 Result = 100 * static_cast<double>(Fraction) / All; 89 90 std::stringstream Str; 91 Str << std::setprecision(4) << Msg << ": " << Fraction << " [" << Result 92 << "% of " << PercentageOfMsg << "]"; 93 if (LineEnd) 94 Str << "\n"; 95 return Str.str(); 96 } 97 98 void ImportedFunctionsInliningStatistics::dump(const bool Verbose) { 99 calculateRealInlines(); 100 NonImportedCallers.clear(); 101 102 int32_t InlinedImportedFunctionsCount = 0; 103 int32_t InlinedNotImportedFunctionsCount = 0; 104 105 int32_t InlinedImportedFunctionsToImportingModuleCount = 0; 106 int32_t InlinedNotImportedFunctionsToImportingModuleCount = 0; 107 108 const auto SortedNodes = getSortedNodes(); 109 std::string Out; 110 Out.reserve(5000); 111 raw_string_ostream Ostream(Out); 112 113 Ostream << "------- Dumping inliner stats for [" << ModuleName 114 << "] -------\n"; 115 116 if (Verbose) 117 Ostream << "-- List of inlined functions:\n"; 118 119 for (const auto &Node : SortedNodes) { 120 assert(Node->second->NumberOfInlines >= Node->second->NumberOfRealInlines); 121 if (Node->second->NumberOfInlines == 0) 122 continue; 123 124 if (Node->second->Imported) { 125 InlinedImportedFunctionsCount++; 126 InlinedImportedFunctionsToImportingModuleCount += 127 int(Node->second->NumberOfRealInlines > 0); 128 } else { 129 InlinedNotImportedFunctionsCount++; 130 InlinedNotImportedFunctionsToImportingModuleCount += 131 int(Node->second->NumberOfRealInlines > 0); 132 } 133 134 if (Verbose) 135 Ostream << "Inlined " 136 << (Node->second->Imported ? "imported " : "not imported ") 137 << "function [" << Node->first() << "]" 138 << ": #inlines = " << Node->second->NumberOfInlines 139 << ", #inlines_to_importing_module = " 140 << Node->second->NumberOfRealInlines << "\n"; 141 } 142 143 auto InlinedFunctionsCount = 144 InlinedImportedFunctionsCount + InlinedNotImportedFunctionsCount; 145 auto NotImportedFuncCount = AllFunctions - ImportedFunctions; 146 auto ImportedNotInlinedIntoModule = 147 ImportedFunctions - InlinedImportedFunctionsToImportingModuleCount; 148 149 Ostream << "-- Summary:\n" 150 << "All functions: " << AllFunctions 151 << ", imported functions: " << ImportedFunctions << "\n" 152 << getStatString("inlined functions", InlinedFunctionsCount, 153 AllFunctions, "all functions") 154 << getStatString("imported functions inlined anywhere", 155 InlinedImportedFunctionsCount, ImportedFunctions, 156 "imported functions") 157 << getStatString("imported functions inlined into importing module", 158 InlinedImportedFunctionsToImportingModuleCount, 159 ImportedFunctions, "imported functions", 160 /*LineEnd=*/false) 161 << getStatString(", remaining", ImportedNotInlinedIntoModule, 162 ImportedFunctions, "imported functions") 163 << getStatString("non-imported functions inlined anywhere", 164 InlinedNotImportedFunctionsCount, 165 NotImportedFuncCount, "non-imported functions") 166 << getStatString( 167 "non-imported functions inlined into importing module", 168 InlinedNotImportedFunctionsToImportingModuleCount, 169 NotImportedFuncCount, "non-imported functions"); 170 Ostream.flush(); 171 dbgs() << Out; 172 } 173 174 void ImportedFunctionsInliningStatistics::calculateRealInlines() { 175 // Removing duplicated Callers. 176 llvm::sort(NonImportedCallers); 177 NonImportedCallers.erase(llvm::unique(NonImportedCallers), 178 NonImportedCallers.end()); 179 180 for (const auto &Name : NonImportedCallers) { 181 auto &Node = *NodesMap[Name]; 182 if (!Node.Visited) 183 dfs(Node); 184 } 185 } 186 187 void ImportedFunctionsInliningStatistics::dfs(InlineGraphNode &GraphNode) { 188 assert(!GraphNode.Visited); 189 GraphNode.Visited = true; 190 for (auto *const InlinedFunctionNode : GraphNode.InlinedCallees) { 191 InlinedFunctionNode->NumberOfRealInlines++; 192 if (!InlinedFunctionNode->Visited) 193 dfs(*InlinedFunctionNode); 194 } 195 } 196 197 ImportedFunctionsInliningStatistics::SortedNodesTy 198 ImportedFunctionsInliningStatistics::getSortedNodes() { 199 SortedNodesTy SortedNodes; 200 SortedNodes.reserve(NodesMap.size()); 201 for (const NodesMapTy::value_type &Node : NodesMap) 202 SortedNodes.push_back(&Node); 203 204 llvm::sort(SortedNodes, [&](const SortedNodesTy::value_type &Lhs, 205 const SortedNodesTy::value_type &Rhs) { 206 if (Lhs->second->NumberOfInlines != Rhs->second->NumberOfInlines) 207 return Lhs->second->NumberOfInlines > Rhs->second->NumberOfInlines; 208 if (Lhs->second->NumberOfRealInlines != Rhs->second->NumberOfRealInlines) 209 return Lhs->second->NumberOfRealInlines > 210 Rhs->second->NumberOfRealInlines; 211 return Lhs->first() < Rhs->first(); 212 }); 213 return SortedNodes; 214 } 215