LLVM  4.0.0
ImportedFunctionsInliningStatistics.cpp
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1 //===-- ImportedFunctionsInliningStats.cpp ----------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // Generating inliner statistics for imported functions, mostly useful for
10 // ThinLTO.
11 //===----------------------------------------------------------------------===//
12 
14 #include "llvm/ADT/STLExtras.h"
15 #include "llvm/IR/Function.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/Support/Debug.h"
19 #include <algorithm>
20 #include <iomanip>
21 #include <sstream>
22 using namespace llvm;
23 
24 ImportedFunctionsInliningStatistics::InlineGraphNode &
25 ImportedFunctionsInliningStatistics::createInlineGraphNode(const Function &F) {
26 
27  auto &ValueLookup = NodesMap[F.getName()];
28  if (!ValueLookup) {
29  ValueLookup = llvm::make_unique<InlineGraphNode>();
30  ValueLookup->Imported = F.getMetadata("thinlto_src_module") != nullptr;
31  }
32  return *ValueLookup;
33 }
34 
36  const Function &Callee) {
37 
38  InlineGraphNode &CallerNode = createInlineGraphNode(Caller);
39  InlineGraphNode &CalleeNode = createInlineGraphNode(Callee);
40  CalleeNode.NumberOfInlines++;
41 
42  if (!CallerNode.Imported && !CalleeNode.Imported) {
43  // Direct inline from not imported callee to not imported caller, so we
44  // don't have to add this to graph. It might be very helpful if you wanna
45  // get the inliner statistics in compile step where there are no imported
46  // functions. In this case the graph would be empty.
47  CalleeNode.NumberOfRealInlines++;
48  return;
49  }
50 
51  CallerNode.InlinedCallees.push_back(&CalleeNode);
52  if (!CallerNode.Imported) {
53  // We could avoid second lookup, but it would make the code ultra ugly.
54  auto It = NodesMap.find(Caller.getName());
55  assert(It != NodesMap.end() && "The node should be already there.");
56  // Save Caller as a starting node for traversal. The string has to be one
57  // from map because Caller can disappear (and function name with it).
58  NonImportedCallers.push_back(It->first());
59  }
60 }
61 
63  ModuleName = M.getName();
64  for (const auto &F : M.functions()) {
65  AllFunctions++;
66  ImportedFunctions += int(F.getMetadata("thinlto_src_module") != nullptr);
67  }
68 }
69 static std::string getStatString(const char *Msg, int32_t Fraction, int32_t All,
70  const char *PercentageOfMsg,
71  bool LineEnd = true) {
72  double Result = 0;
73  if (All != 0)
74  Result = 100 * static_cast<double>(Fraction) / All;
75 
76  std::stringstream Str;
77  Str << std::setprecision(4) << Msg << ": " << Fraction << " [" << Result
78  << "% of " << PercentageOfMsg << "]";
79  if (LineEnd)
80  Str << "\n";
81  return Str.str();
82 }
83 
85  calculateRealInlines();
86  NonImportedCallers.clear();
87 
88  int32_t InlinedImportedFunctionsCount = 0;
89  int32_t InlinedNotImportedFunctionsCount = 0;
90 
91  int32_t InlinedImportedFunctionsToImportingModuleCount = 0;
92  int32_t InlinedNotImportedFunctionsToImportingModuleCount = 0;
93 
94  const auto SortedNodes = getSortedNodes();
95  std::string Out;
96  Out.reserve(5000);
97  raw_string_ostream Ostream(Out);
98 
99  Ostream << "------- Dumping inliner stats for [" << ModuleName
100  << "] -------\n";
101 
102  if (Verbose)
103  Ostream << "-- List of inlined functions:\n";
104 
105  for (const auto &Node : SortedNodes) {
106  assert(Node->second->NumberOfInlines >= Node->second->NumberOfRealInlines);
107  if (Node->second->NumberOfInlines == 0)
108  continue;
109 
110  if (Node->second->Imported) {
111  InlinedImportedFunctionsCount++;
112  InlinedImportedFunctionsToImportingModuleCount +=
113  int(Node->second->NumberOfRealInlines > 0);
114  } else {
115  InlinedNotImportedFunctionsCount++;
116  InlinedNotImportedFunctionsToImportingModuleCount +=
117  int(Node->second->NumberOfRealInlines > 0);
118  }
119 
120  if (Verbose)
121  Ostream << "Inlined "
122  << (Node->second->Imported ? "imported " : "not imported ")
123  << "function [" << Node->first() << "]"
124  << ": #inlines = " << Node->second->NumberOfInlines
125  << ", #inlines_to_importing_module = "
126  << Node->second->NumberOfRealInlines << "\n";
127  }
128 
129  auto InlinedFunctionsCount =
130  InlinedImportedFunctionsCount + InlinedNotImportedFunctionsCount;
131  auto NotImportedFuncCount = AllFunctions - ImportedFunctions;
132  auto ImportedNotInlinedIntoModule =
133  ImportedFunctions - InlinedImportedFunctionsToImportingModuleCount;
134 
135  Ostream << "-- Summary:\n"
136  << "All functions: " << AllFunctions
137  << ", imported functions: " << ImportedFunctions << "\n"
138  << getStatString("inlined functions", InlinedFunctionsCount,
139  AllFunctions, "all functions")
140  << getStatString("imported functions inlined anywhere",
141  InlinedImportedFunctionsCount, ImportedFunctions,
142  "imported functions")
143  << getStatString("imported functions inlined into importing module",
144  InlinedImportedFunctionsToImportingModuleCount,
145  ImportedFunctions, "imported functions",
146  /*LineEnd=*/false)
147  << getStatString(", remaining", ImportedNotInlinedIntoModule,
148  ImportedFunctions, "imported functions")
149  << getStatString("non-imported functions inlined anywhere",
150  InlinedNotImportedFunctionsCount,
151  NotImportedFuncCount, "non-imported functions")
152  << getStatString(
153  "non-imported functions inlined into importing module",
154  InlinedNotImportedFunctionsToImportingModuleCount,
155  NotImportedFuncCount, "non-imported functions");
156  Ostream.flush();
157  dbgs() << Out;
158 }
159 
160 void ImportedFunctionsInliningStatistics::calculateRealInlines() {
161  // Removing duplicated Callers.
162  std::sort(NonImportedCallers.begin(), NonImportedCallers.end());
163  NonImportedCallers.erase(
164  std::unique(NonImportedCallers.begin(), NonImportedCallers.end()),
165  NonImportedCallers.end());
166 
167  for (const auto &Name : NonImportedCallers) {
168  auto &Node = *NodesMap[Name];
169  if (!Node.Visited)
170  dfs(Node);
171  }
172 }
173 
174 void ImportedFunctionsInliningStatistics::dfs(InlineGraphNode &GraphNode) {
175  assert(!GraphNode.Visited);
176  GraphNode.Visited = true;
177  for (auto *const InlinedFunctionNode : GraphNode.InlinedCallees) {
178  InlinedFunctionNode->NumberOfRealInlines++;
179  if (!InlinedFunctionNode->Visited)
180  dfs(*InlinedFunctionNode);
181  }
182 }
183 
184 ImportedFunctionsInliningStatistics::SortedNodesTy
185 ImportedFunctionsInliningStatistics::getSortedNodes() {
186  SortedNodesTy SortedNodes;
187  SortedNodes.reserve(NodesMap.size());
188  for (const NodesMapTy::value_type& Node : NodesMap)
189  SortedNodes.push_back(&Node);
190 
191  std::sort(
192  SortedNodes.begin(), SortedNodes.end(),
193  [&](const SortedNodesTy::value_type &Lhs,
194  const SortedNodesTy::value_type &Rhs) {
195  if (Lhs->second->NumberOfInlines != Rhs->second->NumberOfInlines)
196  return Lhs->second->NumberOfInlines > Rhs->second->NumberOfInlines;
197  if (Lhs->second->NumberOfRealInlines != Rhs->second->NumberOfRealInlines)
198  return Lhs->second->NumberOfRealInlines >
199  Rhs->second->NumberOfRealInlines;
200  return Lhs->first() < Rhs->first();
201  });
202  return SortedNodes;
203 }
void setModuleInfo(const Module &M)
Set information like AllFunctions, ImportedFunctions, ModuleName.
A Module instance is used to store all the information related to an LLVM module. ...
Definition: Module.h:52
void recordInline(const Function &Caller, const Function &Callee)
Record inline of.
iterator find(StringRef Key)
Definition: StringMap.h:315
StringRef getName() const
Return a constant reference to the value's name.
Definition: Value.cpp:191
StringRef getName() const
Get a short "name" for the module.
Definition: Module.h:205
#define F(x, y, z)
Definition: MD5.cpp:51
iterator_range< iterator > functions()
Definition: Module.h:546
unsigned size() const
Definition: StringMap.h:114
Module.h This file contains the declarations for the Module class.
static std::string getStatString(const char *Msg, int32_t Fraction, int32_t All, const char *PercentageOfMsg, bool LineEnd=true)
StringMapEntry< ValueTy > value_type
Definition: StringMap.h:296
raw_ostream & dbgs()
dbgs() - This returns a reference to a raw_ostream for debugging messages.
Definition: Debug.cpp:132
void dump(bool Verbose)
Dump stats computed with InlinerStatistics class.
MDNode * getMetadata(unsigned KindID) const
Get the current metadata attachments for the given kind, if any.
Definition: Metadata.cpp:1391
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
A raw_ostream that writes to an std::string.
Definition: raw_ostream.h:463
iterator end()
Definition: StringMap.h:305