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/Analysis/AliasAnalysis.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/Pass.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, Partial, Must;
33 unsigned NoMR, JustRef, JustMod, MR;
36 static char ID; // Class identification, replacement for typeinfo
37 AliasAnalysisCounter() : ModulePass(ID) {
38 initializeAliasAnalysisCounterPass(*PassRegistry::getPassRegistry());
39 No = May = Partial = Must = 0;
40 NoMR = JustRef = JustMod = MR = 0;
43 void printLine(const char *Desc, unsigned Val, unsigned Sum) {
44 errs() << " " << Val << " " << Desc << " responses ("
45 << Val*100/Sum << "%)\n";
47 ~AliasAnalysisCounter() override {
48 unsigned AASum = No+May+Partial+Must;
49 unsigned MRSum = NoMR+JustRef+JustMod+MR;
50 if (AASum + MRSum) { // Print a report if any counted queries occurred...
51 errs() << "\n===== Alias Analysis Counter Report =====\n"
52 << " Analysis counted:\n"
53 << " " << AASum << " Total Alias Queries Performed\n";
55 printLine("no alias", No, AASum);
56 printLine("may alias", May, AASum);
57 printLine("partial alias", Partial, AASum);
58 printLine("must alias", Must, AASum);
59 errs() << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
60 << May*100/AASum << "%/"
61 << Partial*100/AASum << "%/"
62 << Must*100/AASum<<"%\n\n";
65 errs() << " " << MRSum << " Total MRI_Mod/MRI_Ref Queries Performed\n";
67 printLine("no mod/ref", NoMR, MRSum);
68 printLine("ref", JustRef, MRSum);
69 printLine("mod", JustMod, MRSum);
70 printLine("mod/ref", MR, MRSum);
71 errs() << " MRI_Mod/MRI_Ref Analysis Counter Summary: "
72 << NoMR * 100 / MRSum << "%/" << JustRef * 100 / MRSum << "%/"
73 << JustMod * 100 / MRSum << "%/" << MR * 100 / MRSum
79 bool runOnModule(Module &M) override {
81 InitializeAliasAnalysis(this, &M.getDataLayout());
85 void getAnalysisUsage(AnalysisUsage &AU) const override {
86 AliasAnalysis::getAnalysisUsage(AU);
87 AU.addRequired<AliasAnalysis>();
91 /// getAdjustedAnalysisPointer - This method is used when a pass implements
92 /// an analysis interface through multiple inheritance. If needed, it
93 /// should override this to adjust the this pointer as needed for the
94 /// specified pass info.
95 void *getAdjustedAnalysisPointer(AnalysisID PI) override {
96 if (PI == &AliasAnalysis::ID)
97 return (AliasAnalysis*)this;
101 // FIXME: We could count these too...
102 bool pointsToConstantMemory(const MemoryLocation &Loc,
103 bool OrLocal) override {
104 return getAnalysis<AliasAnalysis>().pointsToConstantMemory(Loc, OrLocal);
107 // Forwarding functions: just delegate to a real AA implementation, counting
108 // the number of responses...
109 AliasResult alias(const MemoryLocation &LocA,
110 const MemoryLocation &LocB) override;
112 ModRefInfo getModRefInfo(ImmutableCallSite CS,
113 const MemoryLocation &Loc) override;
114 ModRefInfo getModRefInfo(ImmutableCallSite CS1,
115 ImmutableCallSite CS2) override {
116 return AliasAnalysis::getModRefInfo(CS1,CS2);
121 char AliasAnalysisCounter::ID = 0;
122 INITIALIZE_AG_PASS(AliasAnalysisCounter, AliasAnalysis, "count-aa",
123 "Count Alias Analysis Query Responses", false, true, false)
125 ModulePass *llvm::createAliasAnalysisCounterPass() {
126 return new AliasAnalysisCounter();
129 AliasResult AliasAnalysisCounter::alias(const MemoryLocation &LocA,
130 const MemoryLocation &LocB) {
131 AliasResult R = getAnalysis<AliasAnalysis>().alias(LocA, LocB);
133 const char *AliasString = nullptr;
135 case NoAlias: No++; AliasString = "No alias"; break;
136 case MayAlias: May++; AliasString = "May alias"; break;
137 case PartialAlias: Partial++; AliasString = "Partial alias"; break;
138 case MustAlias: Must++; AliasString = "Must alias"; break;
141 if (PrintAll || (PrintAllFailures && R == MayAlias)) {
142 errs() << AliasString << ":\t";
143 errs() << "[" << LocA.Size << "B] ";
144 LocA.Ptr->printAsOperand(errs(), true, M);
146 errs() << "[" << LocB.Size << "B] ";
147 LocB.Ptr->printAsOperand(errs(), true, M);
154 ModRefInfo AliasAnalysisCounter::getModRefInfo(ImmutableCallSite CS,
155 const MemoryLocation &Loc) {
156 ModRefInfo R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, Loc);
158 const char *MRString = nullptr;
162 MRString = "MRI_NoModRef";
166 MRString = "JustRef";
170 MRString = "JustMod";
174 MRString = "MRI_ModRef";
178 if (PrintAll || (PrintAllFailures && R == MRI_ModRef)) {
179 errs() << MRString << ": Ptr: ";
180 errs() << "[" << Loc.Size << "B] ";
181 Loc.Ptr->printAsOperand(errs(), true, M);
182 errs() << "\t<->" << *CS.getInstruction() << '\n';