1 //===- AliasAnalysisCounter.cpp - Alias Analysis Query Counter ------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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/Streams.h"
26 PrintAll("count-aa-print-all-queries", cl::ReallyHidden);
28 PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden);
30 class AliasAnalysisCounter : public ModulePass, public AliasAnalysis {
31 unsigned No, May, Must;
32 unsigned NoMR, JustRef, JustMod, MR;
36 AliasAnalysisCounter() {
38 NoMR = JustRef = JustMod = MR = 0;
41 void printLine(const char *Desc, unsigned Val, unsigned Sum) {
42 cerr << " " << Val << " " << Desc << " responses ("
43 << Val*100/Sum << "%)\n";
45 ~AliasAnalysisCounter() {
46 unsigned AASum = No+May+Must;
47 unsigned MRSum = NoMR+JustRef+JustMod+MR;
48 if (AASum + MRSum) { // Print a report if any counted queries occurred...
49 cerr << "\n===== Alias Analysis Counter Report =====\n"
50 << " Analysis counted: " << Name << "\n"
51 << " " << AASum << " Total Alias Queries Performed\n";
53 printLine("no alias", No, AASum);
54 printLine("may alias", May, AASum);
55 printLine("must alias", Must, AASum);
56 cerr << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
57 << May*100/AASum << "%/" << Must*100/AASum<<"%\n\n";
60 cerr << " " << MRSum << " Total Mod/Ref Queries Performed\n";
62 printLine("no mod/ref", NoMR, MRSum);
63 printLine("ref", JustRef, MRSum);
64 printLine("mod", JustMod, MRSum);
65 printLine("mod/ref", MR, MRSum);
66 cerr << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum<< "%/"
67 << JustRef*100/MRSum << "%/" << JustMod*100/MRSum << "%/"
68 << MR*100/MRSum <<"%\n\n";
73 bool runOnModule(Module &M) {
75 InitializeAliasAnalysis(this);
76 Name = dynamic_cast<Pass*>(&getAnalysis<AliasAnalysis>())->getPassName();
80 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
81 AliasAnalysis::getAnalysisUsage(AU);
82 AU.addRequired<AliasAnalysis>();
86 // FIXME: We could count these too...
87 bool pointsToConstantMemory(const Value *P) {
88 return getAnalysis<AliasAnalysis>().pointsToConstantMemory(P);
90 bool doesNotAccessMemory(Function *F) {
91 return getAnalysis<AliasAnalysis>().doesNotAccessMemory(F);
93 bool onlyReadsMemory(Function *F) {
94 return getAnalysis<AliasAnalysis>().onlyReadsMemory(F);
98 // Forwarding functions: just delegate to a real AA implementation, counting
99 // the number of responses...
100 AliasResult alias(const Value *V1, unsigned V1Size,
101 const Value *V2, unsigned V2Size);
103 ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
104 ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
105 return AliasAnalysis::getModRefInfo(CS1,CS2);
109 RegisterPass<AliasAnalysisCounter>
110 X("count-aa", "Count Alias Analysis Query Responses");
111 RegisterAnalysisGroup<AliasAnalysis> Y(X);
114 ModulePass *llvm::createAliasAnalysisCounterPass() {
115 return new AliasAnalysisCounter();
118 AliasAnalysis::AliasResult
119 AliasAnalysisCounter::alias(const Value *V1, unsigned V1Size,
120 const Value *V2, unsigned V2Size) {
121 AliasResult R = getAnalysis<AliasAnalysis>().alias(V1, V1Size, V2, V2Size);
123 const char *AliasString;
125 default: assert(0 && "Unknown alias type!");
126 case NoAlias: No++; AliasString = "No alias"; break;
127 case MayAlias: May++; AliasString = "May alias"; break;
128 case MustAlias: Must++; AliasString = "Must alias"; break;
131 if (PrintAll || (PrintAllFailures && R == MayAlias)) {
132 cerr << AliasString << ":\t";
133 cerr << "[" << V1Size << "B] ";
134 WriteAsOperand(std::cerr, V1, true, M) << ", ";
135 cerr << "[" << V2Size << "B] ";
136 WriteAsOperand(std::cerr, V2, true, M) << "\n";
142 AliasAnalysis::ModRefResult
143 AliasAnalysisCounter::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
144 ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, P, Size);
146 const char *MRString;
148 default: assert(0 && "Unknown mod/ref type!");
149 case NoModRef: NoMR++; MRString = "NoModRef"; break;
150 case Ref: JustRef++; MRString = "JustRef"; break;
151 case Mod: JustMod++; MRString = "JustMod"; break;
152 case ModRef: MR++; MRString = "ModRef"; break;
155 if (PrintAll || (PrintAllFailures && R == ModRef)) {
156 cerr << MRString << ": Ptr: ";
157 cerr << "[" << Size << "B] ";
158 WriteAsOperand(std::cerr, P, true, M);
159 cerr << "\t<->" << *CS.getInstruction();