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"
25 PrintAll("count-aa-print-all-queries", cl::ReallyHidden);
27 PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden);
29 class AliasAnalysisCounter : public ModulePass, public AliasAnalysis {
30 unsigned No, May, Must;
31 unsigned NoMR, JustRef, JustMod, MR;
35 AliasAnalysisCounter() {
37 NoMR = JustRef = JustMod = MR = 0;
40 void printLine(const char *Desc, unsigned Val, unsigned Sum) {
41 cerr << " " << Val << " " << Desc << " responses ("
42 << Val*100/Sum << "%)\n";
44 ~AliasAnalysisCounter() {
45 unsigned AASum = No+May+Must;
46 unsigned MRSum = NoMR+JustRef+JustMod+MR;
47 if (AASum + MRSum) { // Print a report if any counted queries occurred...
48 cerr << "\n===== Alias Analysis Counter Report =====\n"
49 << " Analysis counted: " << Name << "\n"
50 << " " << AASum << " Total Alias Queries Performed\n";
52 printLine("no alias", No, AASum);
53 printLine("may alias", May, AASum);
54 printLine("must alias", Must, AASum);
55 cerr << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
56 << May*100/AASum << "%/" << Must*100/AASum<<"%\n\n";
59 cerr << " " << MRSum << " Total Mod/Ref Queries Performed\n";
61 printLine("no mod/ref", NoMR, MRSum);
62 printLine("ref", JustRef, MRSum);
63 printLine("mod", JustMod, MRSum);
64 printLine("mod/ref", MR, MRSum);
65 cerr << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum<< "%/"
66 << JustRef*100/MRSum << "%/" << JustMod*100/MRSum << "%/"
67 << MR*100/MRSum <<"%\n\n";
72 bool runOnModule(Module &M) {
74 InitializeAliasAnalysis(this);
75 Name = dynamic_cast<Pass*>(&getAnalysis<AliasAnalysis>())->getPassName();
79 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
80 AliasAnalysis::getAnalysisUsage(AU);
81 AU.addRequired<AliasAnalysis>();
85 // FIXME: We could count these too...
86 bool pointsToConstantMemory(const Value *P) {
87 return getAnalysis<AliasAnalysis>().pointsToConstantMemory(P);
89 bool doesNotAccessMemory(Function *F) {
90 return getAnalysis<AliasAnalysis>().doesNotAccessMemory(F);
92 bool onlyReadsMemory(Function *F) {
93 return getAnalysis<AliasAnalysis>().onlyReadsMemory(F);
97 // Forwarding functions: just delegate to a real AA implementation, counting
98 // the number of responses...
99 AliasResult alias(const Value *V1, unsigned V1Size,
100 const Value *V2, unsigned V2Size);
102 ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
103 ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
104 return AliasAnalysis::getModRefInfo(CS1,CS2);
108 RegisterPass<AliasAnalysisCounter>
109 X("count-aa", "Count Alias Analysis Query Responses");
110 RegisterAnalysisGroup<AliasAnalysis> Y(X);
113 ModulePass *llvm::createAliasAnalysisCounterPass() {
114 return new AliasAnalysisCounter();
117 AliasAnalysis::AliasResult
118 AliasAnalysisCounter::alias(const Value *V1, unsigned V1Size,
119 const Value *V2, unsigned V2Size) {
120 AliasResult R = getAnalysis<AliasAnalysis>().alias(V1, V1Size, V2, V2Size);
122 const char *AliasString;
124 default: assert(0 && "Unknown alias type!");
125 case NoAlias: No++; AliasString = "No alias"; break;
126 case MayAlias: May++; AliasString = "May alias"; break;
127 case MustAlias: Must++; AliasString = "Must alias"; break;
130 if (PrintAll || (PrintAllFailures && R == MayAlias)) {
131 cerr << AliasString << ":\t";
132 cerr << "[" << V1Size << "B] ";
133 WriteAsOperand(*cerr.stream(), V1, true, M) << ", ";
134 cerr << "[" << V2Size << "B] ";
135 WriteAsOperand(*cerr.stream(), V2, true, M) << "\n";
141 AliasAnalysis::ModRefResult
142 AliasAnalysisCounter::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
143 ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, P, Size);
145 const char *MRString;
147 default: assert(0 && "Unknown mod/ref type!");
148 case NoModRef: NoMR++; MRString = "NoModRef"; break;
149 case Ref: JustRef++; MRString = "JustRef"; break;
150 case Mod: JustMod++; MRString = "JustMod"; break;
151 case ModRef: MR++; MRString = "ModRef"; break;
154 if (PrintAll || (PrintAllFailures && R == ModRef)) {
155 cerr << MRString << ": Ptr: ";
156 cerr << "[" << Size << "B] ";
157 WriteAsOperand(*cerr.stream(), P, true, M);
158 cerr << "\t<->" << *CS.getInstruction();