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AliasAnalysisEvaluator.cpp (198090) AliasAnalysisEvaluator.cpp (198892)
1//===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===//
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// This file implements a simple N^2 alias analysis accuracy evaluator.
11// Basically, for each function in the program, it simply queries to see how the
12// alias analysis implementation answers alias queries between each pair of
13// pointers in the function.
14//
15// This is inspired and adapted from code by: Naveen Neelakantam, Francesco
16// Spadini, and Wojciech Stryjewski.
17//
18//===----------------------------------------------------------------------===//
19
20#include "llvm/Constants.h"
21#include "llvm/DerivedTypes.h"
22#include "llvm/Function.h"
23#include "llvm/Instructions.h"
24#include "llvm/Pass.h"
25#include "llvm/Analysis/Passes.h"
26#include "llvm/Analysis/AliasAnalysis.h"
27#include "llvm/Assembly/Writer.h"
28#include "llvm/Target/TargetData.h"
29#include "llvm/Support/InstIterator.h"
30#include "llvm/Support/CommandLine.h"
1//===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===//
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// This file implements a simple N^2 alias analysis accuracy evaluator.
11// Basically, for each function in the program, it simply queries to see how the
12// alias analysis implementation answers alias queries between each pair of
13// pointers in the function.
14//
15// This is inspired and adapted from code by: Naveen Neelakantam, Francesco
16// Spadini, and Wojciech Stryjewski.
17//
18//===----------------------------------------------------------------------===//
19
20#include "llvm/Constants.h"
21#include "llvm/DerivedTypes.h"
22#include "llvm/Function.h"
23#include "llvm/Instructions.h"
24#include "llvm/Pass.h"
25#include "llvm/Analysis/Passes.h"
26#include "llvm/Analysis/AliasAnalysis.h"
27#include "llvm/Assembly/Writer.h"
28#include "llvm/Target/TargetData.h"
29#include "llvm/Support/InstIterator.h"
30#include "llvm/Support/CommandLine.h"
31#include "llvm/Support/Compiler.h"
32#include "llvm/Support/raw_ostream.h"
33#include "llvm/ADT/SetVector.h"
34using namespace llvm;
35
36static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
37
38static cl::opt<bool> PrintNoAlias("print-no-aliases", cl::ReallyHidden);
39static cl::opt<bool> PrintMayAlias("print-may-aliases", cl::ReallyHidden);
40static cl::opt<bool> PrintMustAlias("print-must-aliases", cl::ReallyHidden);
41
42static cl::opt<bool> PrintNoModRef("print-no-modref", cl::ReallyHidden);
43static cl::opt<bool> PrintMod("print-mod", cl::ReallyHidden);
44static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden);
45static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden);
46
47namespace {
31#include "llvm/Support/raw_ostream.h"
32#include "llvm/ADT/SetVector.h"
33using namespace llvm;
34
35static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
36
37static cl::opt<bool> PrintNoAlias("print-no-aliases", cl::ReallyHidden);
38static cl::opt<bool> PrintMayAlias("print-may-aliases", cl::ReallyHidden);
39static cl::opt<bool> PrintMustAlias("print-must-aliases", cl::ReallyHidden);
40
41static cl::opt<bool> PrintNoModRef("print-no-modref", cl::ReallyHidden);
42static cl::opt<bool> PrintMod("print-mod", cl::ReallyHidden);
43static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden);
44static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden);
45
46namespace {
48 class VISIBILITY_HIDDEN AAEval : public FunctionPass {
47 class AAEval : public FunctionPass {
49 unsigned NoAlias, MayAlias, MustAlias;
50 unsigned NoModRef, Mod, Ref, ModRef;
51
52 public:
53 static char ID; // Pass identification, replacement for typeid
54 AAEval() : FunctionPass(&ID) {}
55
56 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
57 AU.addRequired<AliasAnalysis>();
58 AU.setPreservesAll();
59 }
60
61 bool doInitialization(Module &M) {
62 NoAlias = MayAlias = MustAlias = 0;
63 NoModRef = Mod = Ref = ModRef = 0;
64
65 if (PrintAll) {
66 PrintNoAlias = PrintMayAlias = PrintMustAlias = true;
67 PrintNoModRef = PrintMod = PrintRef = PrintModRef = true;
68 }
69 return false;
70 }
71
72 bool runOnFunction(Function &F);
73 bool doFinalization(Module &M);
74 };
75}
76
77char AAEval::ID = 0;
78static RegisterPass<AAEval>
79X("aa-eval", "Exhaustive Alias Analysis Precision Evaluator", false, true);
80
81FunctionPass *llvm::createAAEvalPass() { return new AAEval(); }
82
83static void PrintResults(const char *Msg, bool P, const Value *V1,
84 const Value *V2, const Module *M) {
85 if (P) {
86 std::string o1, o2;
87 {
88 raw_string_ostream os1(o1), os2(o2);
89 WriteAsOperand(os1, V1, true, M);
90 WriteAsOperand(os2, V2, true, M);
91 }
92
93 if (o2 < o1)
94 std::swap(o1, o2);
95 errs() << " " << Msg << ":\t"
96 << o1 << ", "
97 << o2 << "\n";
98 }
99}
100
101static inline void
102PrintModRefResults(const char *Msg, bool P, Instruction *I, Value *Ptr,
103 Module *M) {
104 if (P) {
105 errs() << " " << Msg << ": Ptr: ";
106 WriteAsOperand(errs(), Ptr, true, M);
107 errs() << "\t<->" << *I << '\n';
108 }
109}
110
111bool AAEval::runOnFunction(Function &F) {
112 AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
113
114 SetVector<Value *> Pointers;
115 SetVector<CallSite> CallSites;
116
117 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
118 if (isa<PointerType>(I->getType())) // Add all pointer arguments
119 Pointers.insert(I);
120
121 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
122 if (isa<PointerType>(I->getType())) // Add all pointer instructions
123 Pointers.insert(&*I);
124 Instruction &Inst = *I;
125 User::op_iterator OI = Inst.op_begin();
126 CallSite CS = CallSite::get(&Inst);
127 if (CS.getInstruction() &&
128 isa<Function>(CS.getCalledValue()))
129 ++OI; // Skip actual functions for direct function calls.
130 for (; OI != Inst.op_end(); ++OI)
131 if (isa<PointerType>((*OI)->getType()) && !isa<ConstantPointerNull>(*OI))
132 Pointers.insert(*OI);
133
134 if (CS.getInstruction()) CallSites.insert(CS);
135 }
136
137 if (PrintNoAlias || PrintMayAlias || PrintMustAlias ||
138 PrintNoModRef || PrintMod || PrintRef || PrintModRef)
139 errs() << "Function: " << F.getName() << ": " << Pointers.size()
140 << " pointers, " << CallSites.size() << " call sites\n";
141
142 // iterate over the worklist, and run the full (n^2)/2 disambiguations
143 for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
144 I1 != E; ++I1) {
145 unsigned I1Size = ~0u;
146 const Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
147 if (I1ElTy->isSized()) I1Size = AA.getTypeStoreSize(I1ElTy);
148
149 for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
150 unsigned I2Size = ~0u;
151 const Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType();
152 if (I2ElTy->isSized()) I2Size = AA.getTypeStoreSize(I2ElTy);
153
154 switch (AA.alias(*I1, I1Size, *I2, I2Size)) {
155 case AliasAnalysis::NoAlias:
156 PrintResults("NoAlias", PrintNoAlias, *I1, *I2, F.getParent());
157 ++NoAlias; break;
158 case AliasAnalysis::MayAlias:
159 PrintResults("MayAlias", PrintMayAlias, *I1, *I2, F.getParent());
160 ++MayAlias; break;
161 case AliasAnalysis::MustAlias:
162 PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent());
163 ++MustAlias; break;
164 default:
165 errs() << "Unknown alias query result!\n";
166 }
167 }
168 }
169
170 // Mod/ref alias analysis: compare all pairs of calls and values
171 for (SetVector<CallSite>::iterator C = CallSites.begin(),
172 Ce = CallSites.end(); C != Ce; ++C) {
173 Instruction *I = C->getInstruction();
174
175 for (SetVector<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end();
176 V != Ve; ++V) {
177 unsigned Size = ~0u;
178 const Type *ElTy = cast<PointerType>((*V)->getType())->getElementType();
179 if (ElTy->isSized()) Size = AA.getTypeStoreSize(ElTy);
180
181 switch (AA.getModRefInfo(*C, *V, Size)) {
182 case AliasAnalysis::NoModRef:
183 PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent());
184 ++NoModRef; break;
185 case AliasAnalysis::Mod:
186 PrintModRefResults(" Mod", PrintMod, I, *V, F.getParent());
187 ++Mod; break;
188 case AliasAnalysis::Ref:
189 PrintModRefResults(" Ref", PrintRef, I, *V, F.getParent());
190 ++Ref; break;
191 case AliasAnalysis::ModRef:
192 PrintModRefResults(" ModRef", PrintModRef, I, *V, F.getParent());
193 ++ModRef; break;
194 default:
195 errs() << "Unknown alias query result!\n";
196 }
197 }
198 }
199
200 return false;
201}
202
203static void PrintPercent(unsigned Num, unsigned Sum) {
204 errs() << "(" << Num*100ULL/Sum << "."
205 << ((Num*1000ULL/Sum) % 10) << "%)\n";
206}
207
208bool AAEval::doFinalization(Module &M) {
209 unsigned AliasSum = NoAlias + MayAlias + MustAlias;
210 errs() << "===== Alias Analysis Evaluator Report =====\n";
211 if (AliasSum == 0) {
212 errs() << " Alias Analysis Evaluator Summary: No pointers!\n";
213 } else {
214 errs() << " " << AliasSum << " Total Alias Queries Performed\n";
215 errs() << " " << NoAlias << " no alias responses ";
216 PrintPercent(NoAlias, AliasSum);
217 errs() << " " << MayAlias << " may alias responses ";
218 PrintPercent(MayAlias, AliasSum);
219 errs() << " " << MustAlias << " must alias responses ";
220 PrintPercent(MustAlias, AliasSum);
221 errs() << " Alias Analysis Evaluator Pointer Alias Summary: "
222 << NoAlias*100/AliasSum << "%/" << MayAlias*100/AliasSum << "%/"
223 << MustAlias*100/AliasSum << "%\n";
224 }
225
226 // Display the summary for mod/ref analysis
227 unsigned ModRefSum = NoModRef + Mod + Ref + ModRef;
228 if (ModRefSum == 0) {
229 errs() << " Alias Analysis Mod/Ref Evaluator Summary: no mod/ref!\n";
230 } else {
231 errs() << " " << ModRefSum << " Total ModRef Queries Performed\n";
232 errs() << " " << NoModRef << " no mod/ref responses ";
233 PrintPercent(NoModRef, ModRefSum);
234 errs() << " " << Mod << " mod responses ";
235 PrintPercent(Mod, ModRefSum);
236 errs() << " " << Ref << " ref responses ";
237 PrintPercent(Ref, ModRefSum);
238 errs() << " " << ModRef << " mod & ref responses ";
239 PrintPercent(ModRef, ModRefSum);
240 errs() << " Alias Analysis Evaluator Mod/Ref Summary: "
241 << NoModRef*100/ModRefSum << "%/" << Mod*100/ModRefSum << "%/"
242 << Ref*100/ModRefSum << "%/" << ModRef*100/ModRefSum << "%\n";
243 }
244
245 return false;
246}
48 unsigned NoAlias, MayAlias, MustAlias;
49 unsigned NoModRef, Mod, Ref, ModRef;
50
51 public:
52 static char ID; // Pass identification, replacement for typeid
53 AAEval() : FunctionPass(&ID) {}
54
55 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
56 AU.addRequired<AliasAnalysis>();
57 AU.setPreservesAll();
58 }
59
60 bool doInitialization(Module &M) {
61 NoAlias = MayAlias = MustAlias = 0;
62 NoModRef = Mod = Ref = ModRef = 0;
63
64 if (PrintAll) {
65 PrintNoAlias = PrintMayAlias = PrintMustAlias = true;
66 PrintNoModRef = PrintMod = PrintRef = PrintModRef = true;
67 }
68 return false;
69 }
70
71 bool runOnFunction(Function &F);
72 bool doFinalization(Module &M);
73 };
74}
75
76char AAEval::ID = 0;
77static RegisterPass<AAEval>
78X("aa-eval", "Exhaustive Alias Analysis Precision Evaluator", false, true);
79
80FunctionPass *llvm::createAAEvalPass() { return new AAEval(); }
81
82static void PrintResults(const char *Msg, bool P, const Value *V1,
83 const Value *V2, const Module *M) {
84 if (P) {
85 std::string o1, o2;
86 {
87 raw_string_ostream os1(o1), os2(o2);
88 WriteAsOperand(os1, V1, true, M);
89 WriteAsOperand(os2, V2, true, M);
90 }
91
92 if (o2 < o1)
93 std::swap(o1, o2);
94 errs() << " " << Msg << ":\t"
95 << o1 << ", "
96 << o2 << "\n";
97 }
98}
99
100static inline void
101PrintModRefResults(const char *Msg, bool P, Instruction *I, Value *Ptr,
102 Module *M) {
103 if (P) {
104 errs() << " " << Msg << ": Ptr: ";
105 WriteAsOperand(errs(), Ptr, true, M);
106 errs() << "\t<->" << *I << '\n';
107 }
108}
109
110bool AAEval::runOnFunction(Function &F) {
111 AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
112
113 SetVector<Value *> Pointers;
114 SetVector<CallSite> CallSites;
115
116 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
117 if (isa<PointerType>(I->getType())) // Add all pointer arguments
118 Pointers.insert(I);
119
120 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
121 if (isa<PointerType>(I->getType())) // Add all pointer instructions
122 Pointers.insert(&*I);
123 Instruction &Inst = *I;
124 User::op_iterator OI = Inst.op_begin();
125 CallSite CS = CallSite::get(&Inst);
126 if (CS.getInstruction() &&
127 isa<Function>(CS.getCalledValue()))
128 ++OI; // Skip actual functions for direct function calls.
129 for (; OI != Inst.op_end(); ++OI)
130 if (isa<PointerType>((*OI)->getType()) && !isa<ConstantPointerNull>(*OI))
131 Pointers.insert(*OI);
132
133 if (CS.getInstruction()) CallSites.insert(CS);
134 }
135
136 if (PrintNoAlias || PrintMayAlias || PrintMustAlias ||
137 PrintNoModRef || PrintMod || PrintRef || PrintModRef)
138 errs() << "Function: " << F.getName() << ": " << Pointers.size()
139 << " pointers, " << CallSites.size() << " call sites\n";
140
141 // iterate over the worklist, and run the full (n^2)/2 disambiguations
142 for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
143 I1 != E; ++I1) {
144 unsigned I1Size = ~0u;
145 const Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
146 if (I1ElTy->isSized()) I1Size = AA.getTypeStoreSize(I1ElTy);
147
148 for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
149 unsigned I2Size = ~0u;
150 const Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType();
151 if (I2ElTy->isSized()) I2Size = AA.getTypeStoreSize(I2ElTy);
152
153 switch (AA.alias(*I1, I1Size, *I2, I2Size)) {
154 case AliasAnalysis::NoAlias:
155 PrintResults("NoAlias", PrintNoAlias, *I1, *I2, F.getParent());
156 ++NoAlias; break;
157 case AliasAnalysis::MayAlias:
158 PrintResults("MayAlias", PrintMayAlias, *I1, *I2, F.getParent());
159 ++MayAlias; break;
160 case AliasAnalysis::MustAlias:
161 PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent());
162 ++MustAlias; break;
163 default:
164 errs() << "Unknown alias query result!\n";
165 }
166 }
167 }
168
169 // Mod/ref alias analysis: compare all pairs of calls and values
170 for (SetVector<CallSite>::iterator C = CallSites.begin(),
171 Ce = CallSites.end(); C != Ce; ++C) {
172 Instruction *I = C->getInstruction();
173
174 for (SetVector<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end();
175 V != Ve; ++V) {
176 unsigned Size = ~0u;
177 const Type *ElTy = cast<PointerType>((*V)->getType())->getElementType();
178 if (ElTy->isSized()) Size = AA.getTypeStoreSize(ElTy);
179
180 switch (AA.getModRefInfo(*C, *V, Size)) {
181 case AliasAnalysis::NoModRef:
182 PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent());
183 ++NoModRef; break;
184 case AliasAnalysis::Mod:
185 PrintModRefResults(" Mod", PrintMod, I, *V, F.getParent());
186 ++Mod; break;
187 case AliasAnalysis::Ref:
188 PrintModRefResults(" Ref", PrintRef, I, *V, F.getParent());
189 ++Ref; break;
190 case AliasAnalysis::ModRef:
191 PrintModRefResults(" ModRef", PrintModRef, I, *V, F.getParent());
192 ++ModRef; break;
193 default:
194 errs() << "Unknown alias query result!\n";
195 }
196 }
197 }
198
199 return false;
200}
201
202static void PrintPercent(unsigned Num, unsigned Sum) {
203 errs() << "(" << Num*100ULL/Sum << "."
204 << ((Num*1000ULL/Sum) % 10) << "%)\n";
205}
206
207bool AAEval::doFinalization(Module &M) {
208 unsigned AliasSum = NoAlias + MayAlias + MustAlias;
209 errs() << "===== Alias Analysis Evaluator Report =====\n";
210 if (AliasSum == 0) {
211 errs() << " Alias Analysis Evaluator Summary: No pointers!\n";
212 } else {
213 errs() << " " << AliasSum << " Total Alias Queries Performed\n";
214 errs() << " " << NoAlias << " no alias responses ";
215 PrintPercent(NoAlias, AliasSum);
216 errs() << " " << MayAlias << " may alias responses ";
217 PrintPercent(MayAlias, AliasSum);
218 errs() << " " << MustAlias << " must alias responses ";
219 PrintPercent(MustAlias, AliasSum);
220 errs() << " Alias Analysis Evaluator Pointer Alias Summary: "
221 << NoAlias*100/AliasSum << "%/" << MayAlias*100/AliasSum << "%/"
222 << MustAlias*100/AliasSum << "%\n";
223 }
224
225 // Display the summary for mod/ref analysis
226 unsigned ModRefSum = NoModRef + Mod + Ref + ModRef;
227 if (ModRefSum == 0) {
228 errs() << " Alias Analysis Mod/Ref Evaluator Summary: no mod/ref!\n";
229 } else {
230 errs() << " " << ModRefSum << " Total ModRef Queries Performed\n";
231 errs() << " " << NoModRef << " no mod/ref responses ";
232 PrintPercent(NoModRef, ModRefSum);
233 errs() << " " << Mod << " mod responses ";
234 PrintPercent(Mod, ModRefSum);
235 errs() << " " << Ref << " ref responses ";
236 PrintPercent(Ref, ModRefSum);
237 errs() << " " << ModRef << " mod & ref responses ";
238 PrintPercent(ModRef, ModRefSum);
239 errs() << " Alias Analysis Evaluator Mod/Ref Summary: "
240 << NoModRef*100/ModRefSum << "%/" << Mod*100/ModRefSum << "%/"
241 << Ref*100/ModRefSum << "%/" << ModRef*100/ModRefSum << "%\n";
242 }
243
244 return false;
245}