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__anon43e365580111::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__anon43e365580111::MemDepPrinter51 void getAnalysisUsage(AnalysisUsage &AU) const override {
52 AU.addRequiredTransitive<AliasAnalysis>();
53 AU.addRequiredTransitive<MemoryDependenceAnalysis>();
54 AU.setPreservesAll();
55 }
56
releaseMemory__anon43e365580111::MemDepPrinter57 void releaseMemory() override {
58 Deps.clear();
59 F = nullptr;
60 }
61
62 private:
getInstTypePair__anon43e365580111::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__anon43e365580111::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(MemoryDependenceAnalysis)82 INITIALIZE_PASS_DEPENDENCY(MemoryDependenceAnalysis)
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 AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
96 MemoryDependenceAnalysis &MDA = getAnalysis<MemoryDependenceAnalysis>();
97
98 // All this code uses non-const interfaces because MemDep is not
99 // const-friendly, though nothing is actually modified.
100 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
101 Instruction *Inst = &*I;
102
103 if (!Inst->mayReadFromMemory() && !Inst->mayWriteToMemory())
104 continue;
105
106 MemDepResult Res = MDA.getDependency(Inst);
107 if (!Res.isNonLocal()) {
108 Deps[Inst].insert(std::make_pair(getInstTypePair(Res),
109 static_cast<BasicBlock *>(nullptr)));
110 } else if (CallSite CS = cast<Value>(Inst)) {
111 const MemoryDependenceAnalysis::NonLocalDepInfo &NLDI =
112 MDA.getNonLocalCallDependency(CS);
113
114 DepSet &InstDeps = Deps[Inst];
115 for (MemoryDependenceAnalysis::NonLocalDepInfo::const_iterator
116 I = NLDI.begin(), E = NLDI.end(); I != E; ++I) {
117 const MemDepResult &Res = I->getResult();
118 InstDeps.insert(std::make_pair(getInstTypePair(Res), I->getBB()));
119 }
120 } else {
121 SmallVector<NonLocalDepResult, 4> NLDI;
122 if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
123 if (!LI->isUnordered()) {
124 // FIXME: Handle atomic/volatile loads.
125 Deps[Inst].insert(std::make_pair(getInstTypePair(nullptr, Unknown),
126 static_cast<BasicBlock *>(nullptr)));
127 continue;
128 }
129 AliasAnalysis::Location Loc = AA.getLocation(LI);
130 MDA.getNonLocalPointerDependency(Loc, true, LI->getParent(), NLDI);
131 } else if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
132 if (!SI->isUnordered()) {
133 // FIXME: Handle atomic/volatile stores.
134 Deps[Inst].insert(std::make_pair(getInstTypePair(nullptr, Unknown),
135 static_cast<BasicBlock *>(nullptr)));
136 continue;
137 }
138 AliasAnalysis::Location Loc = AA.getLocation(SI);
139 MDA.getNonLocalPointerDependency(Loc, false, SI->getParent(), NLDI);
140 } else if (VAArgInst *VI = dyn_cast<VAArgInst>(Inst)) {
141 AliasAnalysis::Location Loc = AA.getLocation(VI);
142 MDA.getNonLocalPointerDependency(Loc, false, VI->getParent(), NLDI);
143 } else {
144 llvm_unreachable("Unknown memory instruction!");
145 }
146
147 DepSet &InstDeps = Deps[Inst];
148 for (SmallVectorImpl<NonLocalDepResult>::const_iterator
149 I = NLDI.begin(), E = NLDI.end(); I != E; ++I) {
150 const MemDepResult &Res = I->getResult();
151 InstDeps.insert(std::make_pair(getInstTypePair(Res), I->getBB()));
152 }
153 }
154 }
155
156 return false;
157 }
158
print(raw_ostream & OS,const Module * M) const159 void MemDepPrinter::print(raw_ostream &OS, const Module *M) const {
160 for (const_inst_iterator I = inst_begin(*F), E = inst_end(*F); I != E; ++I) {
161 const Instruction *Inst = &*I;
162
163 DepSetMap::const_iterator DI = Deps.find(Inst);
164 if (DI == Deps.end())
165 continue;
166
167 const DepSet &InstDeps = DI->second;
168
169 for (DepSet::const_iterator I = InstDeps.begin(), E = InstDeps.end();
170 I != E; ++I) {
171 const Instruction *DepInst = I->first.getPointer();
172 DepType type = I->first.getInt();
173 const BasicBlock *DepBB = I->second;
174
175 OS << " ";
176 OS << DepTypeStr[type];
177 if (DepBB) {
178 OS << " in block ";
179 DepBB->printAsOperand(OS, /*PrintType=*/false, M);
180 }
181 if (DepInst) {
182 OS << " from: ";
183 DepInst->print(OS);
184 }
185 OS << "\n";
186 }
187
188 Inst->print(OS);
189 OS << "\n\n";
190 }
191 }
192