1 //===- AliasAnalysisCounter.cpp - Alias Analysis Query Counter ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a pass which can be used to count how many alias queries
11 // are being made and how the alias analysis implementation being used responds.
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Analysis/Passes.h"
16 #include "llvm/Pass.h"
17 #include "llvm/Analysis/AliasAnalysis.h"
18 #include "llvm/Assembly/Writer.h"
19 #include "llvm/Support/CommandLine.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/ErrorHandling.h"
22 #include "llvm/Support/raw_ostream.h"
26 PrintAll("count-aa-print-all-queries", cl::ReallyHidden, cl::init(true));
28 PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden);
31 class AliasAnalysisCounter : public ModulePass, public AliasAnalysis {
32 unsigned No, May, Must;
33 unsigned NoMR, JustRef, JustMod, MR;
36 static char ID; // Class identification, replacement for typeinfo
37 AliasAnalysisCounter() : ModulePass(&ID) {
39 NoMR = JustRef = JustMod = MR = 0;
42 void printLine(const char *Desc, unsigned Val, unsigned Sum) {
43 errs() << " " << Val << " " << Desc << " responses ("
44 << Val*100/Sum << "%)\n";
46 ~AliasAnalysisCounter() {
47 unsigned AASum = No+May+Must;
48 unsigned MRSum = NoMR+JustRef+JustMod+MR;
49 if (AASum + MRSum) { // Print a report if any counted queries occurred...
50 errs() << "\n===== Alias Analysis Counter Report =====\n"
51 << " Analysis counted:\n"
52 << " " << AASum << " Total Alias Queries Performed\n";
54 printLine("no alias", No, AASum);
55 printLine("may alias", May, AASum);
56 printLine("must alias", Must, AASum);
57 errs() << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
58 << May*100/AASum << "%/" << Must*100/AASum<<"%\n\n";
61 errs() << " " << MRSum << " Total Mod/Ref Queries Performed\n";
63 printLine("no mod/ref", NoMR, MRSum);
64 printLine("ref", JustRef, MRSum);
65 printLine("mod", JustMod, MRSum);
66 printLine("mod/ref", MR, MRSum);
67 errs() << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum
68 << "%/" << JustRef*100/MRSum << "%/" << JustMod*100/MRSum
69 << "%/" << MR*100/MRSum <<"%\n\n";
74 bool runOnModule(Module &M) {
76 InitializeAliasAnalysis(this);
80 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
81 AliasAnalysis::getAnalysisUsage(AU);
82 AU.addRequired<AliasAnalysis>();
86 /// getAdjustedAnalysisPointer - This method is used when a pass implements
87 /// an analysis interface through multiple inheritance. If needed, it
88 /// should override this to adjust the this pointer as needed for the
89 /// specified pass info.
90 virtual void *getAdjustedAnalysisPointer(const PassInfo *PI) {
91 if (PI->isPassID(&AliasAnalysis::ID))
92 return (AliasAnalysis*)this;
96 // FIXME: We could count these too...
97 bool pointsToConstantMemory(const Value *P) {
98 return getAnalysis<AliasAnalysis>().pointsToConstantMemory(P);
101 // Forwarding functions: just delegate to a real AA implementation, counting
102 // the number of responses...
103 AliasResult alias(const Value *V1, unsigned V1Size,
104 const Value *V2, unsigned V2Size);
106 ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
107 ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
108 return AliasAnalysis::getModRefInfo(CS1,CS2);
113 char AliasAnalysisCounter::ID = 0;
114 static RegisterPass<AliasAnalysisCounter>
115 X("count-aa", "Count Alias Analysis Query Responses", false, true);
116 static RegisterAnalysisGroup<AliasAnalysis> Y(X);
118 ModulePass *llvm::createAliasAnalysisCounterPass() {
119 return new AliasAnalysisCounter();
122 AliasAnalysis::AliasResult
123 AliasAnalysisCounter::alias(const Value *V1, unsigned V1Size,
124 const Value *V2, unsigned V2Size) {
125 AliasResult R = getAnalysis<AliasAnalysis>().alias(V1, V1Size, V2, V2Size);
127 const char *AliasString;
129 default: llvm_unreachable("Unknown alias type!");
130 case NoAlias: No++; AliasString = "No alias"; break;
131 case MayAlias: May++; AliasString = "May alias"; break;
132 case MustAlias: Must++; AliasString = "Must alias"; break;
135 if (PrintAll || (PrintAllFailures && R == MayAlias)) {
136 errs() << AliasString << ":\t";
137 errs() << "[" << V1Size << "B] ";
138 WriteAsOperand(errs(), V1, true, M);
140 errs() << "[" << V2Size << "B] ";
141 WriteAsOperand(errs(), V2, true, M);
148 AliasAnalysis::ModRefResult
149 AliasAnalysisCounter::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
150 ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, P, Size);
152 const char *MRString;
154 default: llvm_unreachable("Unknown mod/ref type!");
155 case NoModRef: NoMR++; MRString = "NoModRef"; break;
156 case Ref: JustRef++; MRString = "JustRef"; break;
157 case Mod: JustMod++; MRString = "JustMod"; break;
158 case ModRef: MR++; MRString = "ModRef"; break;
161 if (PrintAll || (PrintAllFailures && R == ModRef)) {
162 errs() << MRString << ": Ptr: ";
163 errs() << "[" << Size << "B] ";
164 WriteAsOperand(errs(), P, true, M);
165 errs() << "\t<->" << *CS.getInstruction() << '\n';