llvm-6502/lib/Analysis/AliasAnalysisCounter.cpp
Duncan Sands dff6710717 Integrate the readonly/readnone logic more deeply
into alias analysis.  This meant updating the API
which now has versions of the getModRefBehavior,
doesNotAccessMemory and onlyReadsMemory methods
which take a callsite parameter.  These should be
used unless the callsite is not known, since in
general they can do a better job than the versions
that take a function.  Also, users should no longer
call the version of getModRefBehavior that takes
both a function and a callsite.  To reduce the
chance of misuse it is now protected.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44487 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-01 07:51:45 +00:00

172 lines
6.0 KiB
C++

//===- AliasAnalysisCounter.cpp - Alias Analysis Query Counter ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and 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/Pass.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Streams.h"
using namespace llvm;
namespace {
cl::opt<bool>
PrintAll("count-aa-print-all-queries", cl::ReallyHidden);
cl::opt<bool>
PrintAllFailures("count-aa-print-all-failed-queries", cl::ReallyHidden);
class VISIBILITY_HIDDEN AliasAnalysisCounter
: public ModulePass, public AliasAnalysis {
unsigned No, May, Must;
unsigned NoMR, JustRef, JustMod, MR;
const char *Name;
Module *M;
public:
static char ID; // Class identification, replacement for typeinfo
AliasAnalysisCounter() : ModulePass((intptr_t) &ID) {
No = May = Must = 0;
NoMR = JustRef = JustMod = MR = 0;
}
void printLine(const char *Desc, unsigned Val, unsigned Sum) {
cerr << " " << Val << " " << Desc << " responses ("
<< Val*100/Sum << "%)\n";
}
~AliasAnalysisCounter() {
unsigned AASum = No+May+Must;
unsigned MRSum = NoMR+JustRef+JustMod+MR;
if (AASum + MRSum) { // Print a report if any counted queries occurred...
cerr << "\n===== Alias Analysis Counter Report =====\n"
<< " Analysis counted: " << Name << "\n"
<< " " << AASum << " Total Alias Queries Performed\n";
if (AASum) {
printLine("no alias", No, AASum);
printLine("may alias", May, AASum);
printLine("must alias", Must, AASum);
cerr << " Alias Analysis Counter Summary: " << No*100/AASum << "%/"
<< May*100/AASum << "%/" << Must*100/AASum<<"%\n\n";
}
cerr << " " << 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);
cerr << " Mod/Ref Analysis Counter Summary: " <<NoMR*100/MRSum<< "%/"
<< JustRef*100/MRSum << "%/" << JustMod*100/MRSum << "%/"
<< MR*100/MRSum <<"%\n\n";
}
}
}
bool runOnModule(Module &M) {
this->M = &M;
InitializeAliasAnalysis(this);
Name = dynamic_cast<Pass*>(&getAnalysis<AliasAnalysis>())->getPassName();
return false;
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AliasAnalysis::getAnalysisUsage(AU);
AU.addRequired<AliasAnalysis>();
AU.setPreservesAll();
}
// FIXME: We could count these too...
bool pointsToConstantMemory(const Value *P) {
return getAnalysis<AliasAnalysis>().pointsToConstantMemory(P);
}
bool doesNotAccessMemory(CallSite CS) {
return getAnalysis<AliasAnalysis>().doesNotAccessMemory(CS);
}
bool doesNotAccessMemory(Function *F) {
return getAnalysis<AliasAnalysis>().doesNotAccessMemory(F);
}
bool onlyReadsMemory(CallSite CS) {
return getAnalysis<AliasAnalysis>().onlyReadsMemory(CS);
}
bool onlyReadsMemory(Function *F) {
return getAnalysis<AliasAnalysis>().onlyReadsMemory(F);
}
// Forwarding functions: just delegate to a real AA implementation, counting
// the number of responses...
AliasResult alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size);
ModRefResult getModRefInfo(CallSite CS, Value *P, unsigned Size);
ModRefResult getModRefInfo(CallSite CS1, CallSite CS2) {
return AliasAnalysis::getModRefInfo(CS1,CS2);
}
};
char AliasAnalysisCounter::ID = 0;
RegisterPass<AliasAnalysisCounter>
X("count-aa", "Count Alias Analysis Query Responses");
RegisterAnalysisGroup<AliasAnalysis> Y(X);
}
ModulePass *llvm::createAliasAnalysisCounterPass() {
return new AliasAnalysisCounter();
}
AliasAnalysis::AliasResult
AliasAnalysisCounter::alias(const Value *V1, unsigned V1Size,
const Value *V2, unsigned V2Size) {
AliasResult R = getAnalysis<AliasAnalysis>().alias(V1, V1Size, V2, V2Size);
const char *AliasString;
switch (R) {
default: assert(0 && "Unknown alias type!");
case NoAlias: No++; AliasString = "No alias"; break;
case MayAlias: May++; AliasString = "May alias"; break;
case MustAlias: Must++; AliasString = "Must alias"; break;
}
if (PrintAll || (PrintAllFailures && R == MayAlias)) {
cerr << AliasString << ":\t";
cerr << "[" << V1Size << "B] ";
WriteAsOperand(*cerr.stream(), V1, true, M) << ", ";
cerr << "[" << V2Size << "B] ";
WriteAsOperand(*cerr.stream(), V2, true, M) << "\n";
}
return R;
}
AliasAnalysis::ModRefResult
AliasAnalysisCounter::getModRefInfo(CallSite CS, Value *P, unsigned Size) {
ModRefResult R = getAnalysis<AliasAnalysis>().getModRefInfo(CS, P, Size);
const char *MRString;
switch (R) {
default: assert(0 && "Unknown mod/ref type!");
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)) {
cerr << MRString << ": Ptr: ";
cerr << "[" << Size << "B] ";
WriteAsOperand(*cerr.stream(), P, true, M);
cerr << "\t<->" << *CS.getInstruction();
}
return R;
}