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//===- AliasAnalysisCounter.cpp - Alias Analysis Query Counter ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements a pass which can be used to count how many alias queries
// are being made and how the alias analysis implementation being used responds.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
static cl::opt<bool>
PrintAll("count-aa-print-all-queries", cl::ReallyHidden, cl::init(true));
static cl::opt<bool>
PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden);
namespace {
class AliasAnalysisCounter : public ModulePass, public AliasAnalysis {
unsigned No, May, Partial, Must;
unsigned NoMR, JustRef, JustMod, MR;
Module *M;
public:
static char ID; // Class identification, replacement for typeinfo
AliasAnalysisCounter() : ModulePass(ID) {
initializeAliasAnalysisCounterPass(*PassRegistry::getPassRegistry());
No = May = Partial = Must = 0;
NoMR = JustRef = JustMod = MR = 0;
}
void printLine(const char *Desc, unsigned Val, unsigned Sum) {
errs() << " " << Val << " " << Desc << " responses ("
<< Val*100/Sum << "%)\n";
}
~AliasAnalysisCounter() {
unsigned AASum = No+May+Partial+Must;
unsigned MRSum = NoMR+JustRef+JustMod+MR;
if (AASum + MRSum) { // Print a report if any counted queries occurred...
errs() << "\n===== Alias Analysis Counter Report =====\n"
<< " Analysis counted:\n"
<< " " << AASum << " Total Alias Queries Performed\n";
if (AASum) {
printLine("no alias", No, AASum);
printLine("may alias", May, AASum);
printLine("partial alias", Partial, AASum);
printLine("must alias", Must, AASum);
errs() << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
<< May*100/AASum << "%/"
<< Partial*100/AASum << "%/"
<< Must*100/AASum<<"%\n\n";
}
errs() << " " << MRSum << " Total Mod/Ref Queries Performed\n";
if (MRSum) {
printLine("no mod/ref", NoMR, MRSum);
printLine("ref", JustRef, MRSum);
printLine("mod", JustMod, MRSum);
printLine("mod/ref", MR, MRSum);
errs() << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum
<< "%/" << JustRef*100/MRSum << "%/" << JustMod*100/MRSum
<< "%/" << MR*100/MRSum <<"%\n\n";
}
}
}
bool runOnModule(Module &M) override {
this->M = &M;
InitializeAliasAnalysis(this);
return false;
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AliasAnalysis::getAnalysisUsage(AU);
AU.addRequired<AliasAnalysis>();
AU.setPreservesAll();
}
/// getAdjustedAnalysisPointer - This method is used when a pass implements
/// an analysis interface through multiple inheritance. If needed, it
/// should override this to adjust the this pointer as needed for the
/// specified pass info.
void *getAdjustedAnalysisPointer(AnalysisID PI) override {
if (PI == &AliasAnalysis::ID)
return (AliasAnalysis*)this;
return this;
}
// FIXME: We could count these too...
bool pointsToConstantMemory(const Location &Loc, bool OrLocal) override {
return getAnalysis<AliasAnalysis>().pointsToConstantMemory(Loc, OrLocal);
}
// Forwarding functions: just delegate to a real AA implementation, counting
// the number of responses...
AliasResult alias(const Location &LocA, const Location &LocB) override;
ModRefResult getModRefInfo(ImmutableCallSite CS,
const Location &Loc) override;
ModRefResult getModRefInfo(ImmutableCallSite CS1,
ImmutableCallSite CS2) override {
return AliasAnalysis::getModRefInfo(CS1,CS2);
}
};
}
char AliasAnalysisCounter::ID = 0;
INITIALIZE_AG_PASS(AliasAnalysisCounter, AliasAnalysis, "count-aa",
"Count Alias Analysis Query Responses", false, true, false)
ModulePass *llvm::createAliasAnalysisCounterPass() {
return new AliasAnalysisCounter();
}
AliasAnalysis::AliasResult
AliasAnalysisCounter::alias(const Location &LocA, const Location &LocB) {
AliasResult R = getAnalysis<AliasAnalysis>().alias(LocA, LocB);
const char *AliasString = nullptr;
switch (R) {
case NoAlias: No++; AliasString = "No alias"; break;
case MayAlias: May++; AliasString = "May alias"; break;
case PartialAlias: Partial++; AliasString = "Partial alias"; break;
case MustAlias: Must++; AliasString = "Must alias"; break;
}
if (PrintAll || (PrintAllFailures && R == MayAlias)) {
errs() << AliasString << ":\t";
errs() << "[" << LocA.Size << "B] ";
LocA.Ptr->printAsOperand(errs(), true, M);
errs() << ", ";
errs() << "[" << LocB.Size << "B] ";
LocB.Ptr->printAsOperand(errs(), true, M);
errs() << "\n";
}
return R;
}
AliasAnalysis::ModRefResult
AliasAnalysisCounter::getModRefInfo(ImmutableCallSite CS,
const Location &Loc) {
ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, Loc);
const char *MRString = nullptr;
switch (R) {
case NoModRef: NoMR++; MRString = "NoModRef"; break;
case Ref: JustRef++; MRString = "JustRef"; break;
case Mod: JustMod++; MRString = "JustMod"; break;
case ModRef: MR++; MRString = "ModRef"; break;
}
if (PrintAll || (PrintAllFailures && R == ModRef)) {
errs() << MRString << ": Ptr: ";
errs() << "[" << Loc.Size << "B] ";
Loc.Ptr->printAsOperand(errs(), true, M);
errs() << "\t<->" << *CS.getInstruction() << '\n';
}
return R;
}
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