1 //===- MemDepPrinter.cpp - Printer for MemoryDependenceAnalysis -----------===//
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 //
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "llvm/Analysis/Passes.h"
14 #include "llvm/ADT/SetVector.h"
15 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
16 #include "llvm/IR/CallSite.h"
17 #include "llvm/IR/InstIterator.h"
18 #include "llvm/IR/LLVMContext.h"
19 #include "llvm/Support/ErrorHandling.h"
20 #include "llvm/Support/raw_ostream.h"
21 using namespace llvm;
22
23 namespace {
24 struct MemDepPrinter : public FunctionPass {
25 const Function *F;
26
27 enum DepType {
28 Clobber = 0,
29 Def,
30 NonFuncLocal,
31 Unknown
32 };
33
34 static const char *const DepTypeStr[];
35
36 typedef PointerIntPair<const Instruction *, 2, DepType> InstTypePair;
37 typedef std::pair<InstTypePair, const BasicBlock *> Dep;
38 typedef SmallSetVector<Dep, 4> DepSet;
39 typedef DenseMap<const Instruction *, DepSet> DepSetMap;
40 DepSetMap Deps;
41
42 static char ID; // Pass identifcation, replacement for typeid
MemDepPrinter__anon88716fca0111::MemDepPrinter43 MemDepPrinter() : FunctionPass(ID) {
44 initializeMemDepPrinterPass(*PassRegistry::getPassRegistry());
45 }
46
47 bool runOnFunction(Function &F) override;
48
49 void print(raw_ostream &OS, const Module * = nullptr) const override;
50
getAnalysisUsage__anon88716fca0111::MemDepPrinter51 void getAnalysisUsage(AnalysisUsage &AU) const override {
52 AU.addRequiredTransitive<AAResultsWrapperPass>();
53 AU.addRequiredTransitive<MemoryDependenceWrapperPass>();
54 AU.setPreservesAll();
55 }
56
releaseMemory__anon88716fca0111::MemDepPrinter57 void releaseMemory() override {
58 Deps.clear();
59 F = nullptr;
60 }
61
62 private:
getInstTypePair__anon88716fca0111::MemDepPrinter63 static InstTypePair getInstTypePair(MemDepResult dep) {
64 if (dep.isClobber())
65 return InstTypePair(dep.getInst(), Clobber);
66 if (dep.isDef())
67 return InstTypePair(dep.getInst(), Def);
68 if (dep.isNonFuncLocal())
69 return InstTypePair(dep.getInst(), NonFuncLocal);
70 assert(dep.isUnknown() && "unexpected dependence type");
71 return InstTypePair(dep.getInst(), Unknown);
72 }
getInstTypePair__anon88716fca0111::MemDepPrinter73 static InstTypePair getInstTypePair(const Instruction* inst, DepType type) {
74 return InstTypePair(inst, type);
75 }
76 };
77 }
78
79 char MemDepPrinter::ID = 0;
80 INITIALIZE_PASS_BEGIN(MemDepPrinter, "print-memdeps",
81 "Print MemDeps of function", false, true)
INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)82 INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)
83 INITIALIZE_PASS_END(MemDepPrinter, "print-memdeps",
84 "Print MemDeps of function", false, true)
85
86 FunctionPass *llvm::createMemDepPrinter() {
87 return new MemDepPrinter();
88 }
89
90 const char *const MemDepPrinter::DepTypeStr[]
91 = {"Clobber", "Def", "NonFuncLocal", "Unknown"};
92
runOnFunction(Function & F)93 bool MemDepPrinter::runOnFunction(Function &F) {
94 this->F = &F;
95 MemoryDependenceResults &MDA = getAnalysis<MemoryDependenceWrapperPass>().getMemDep();
96
97 // All this code uses non-const interfaces because MemDep is not
98 // const-friendly, though nothing is actually modified.
99 for (auto &I : instructions(F)) {
100 Instruction *Inst = &I;
101
102 if (!Inst->mayReadFromMemory() && !Inst->mayWriteToMemory())
103 continue;
104
105 MemDepResult Res = MDA.getDependency(Inst);
106 if (!Res.isNonLocal()) {
107 Deps[Inst].insert(std::make_pair(getInstTypePair(Res),
108 static_cast<BasicBlock *>(nullptr)));
109 } else if (auto CS = CallSite(Inst)) {
110 const MemoryDependenceResults::NonLocalDepInfo &NLDI =
111 MDA.getNonLocalCallDependency(CS);
112
113 DepSet &InstDeps = Deps[Inst];
114 for (const NonLocalDepEntry &I : NLDI) {
115 const MemDepResult &Res = I.getResult();
116 InstDeps.insert(std::make_pair(getInstTypePair(Res), I.getBB()));
117 }
118 } else {
119 SmallVector<NonLocalDepResult, 4> NLDI;
120 assert( (isa<LoadInst>(Inst) || isa<StoreInst>(Inst) ||
121 isa<VAArgInst>(Inst)) && "Unknown memory instruction!");
122 MDA.getNonLocalPointerDependency(Inst, NLDI);
123
124 DepSet &InstDeps = Deps[Inst];
125 for (const NonLocalDepResult &I : NLDI) {
126 const MemDepResult &Res = I.getResult();
127 InstDeps.insert(std::make_pair(getInstTypePair(Res), I.getBB()));
128 }
129 }
130 }
131
132 return false;
133 }
134
print(raw_ostream & OS,const Module * M) const135 void MemDepPrinter::print(raw_ostream &OS, const Module *M) const {
136 for (const auto &I : instructions(*F)) {
137 const Instruction *Inst = &I;
138
139 DepSetMap::const_iterator DI = Deps.find(Inst);
140 if (DI == Deps.end())
141 continue;
142
143 const DepSet &InstDeps = DI->second;
144
145 for (const auto &I : InstDeps) {
146 const Instruction *DepInst = I.first.getPointer();
147 DepType type = I.first.getInt();
148 const BasicBlock *DepBB = I.second;
149
150 OS << " ";
151 OS << DepTypeStr[type];
152 if (DepBB) {
153 OS << " in block ";
154 DepBB->printAsOperand(OS, /*PrintType=*/false, M);
155 }
156 if (DepInst) {
157 OS << " from: ";
158 DepInst->print(OS);
159 }
160 OS << "\n";
161 }
162
163 Inst->print(OS);
164 OS << "\n\n";
165 }
166 }
167