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llvm-mirror/lib/Analysis/AliasAnalysisEvaluator.cpp
Dan Gohman bab18cae46 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017
2008-05-13 00:00:25 +00:00

247 lines
8.7 KiB
C++

//===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===//
//
// 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 simple N^2 alias analysis accuracy evaluator.
// Basically, for each function in the program, it simply queries to see how the
// alias analysis implementation answers alias queries between each pair of
// pointers in the function.
//
// This is inspired and adapted from code by: Naveen Neelakantam, Francesco
// Spadini, and Wojciech Stryjewski.
//
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/Passes.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/InstIterator.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Streams.h"
#include <set>
#include <sstream>
using namespace llvm;
static cl::opt<bool> PrintAll("print-all-alias-modref-info", cl::ReallyHidden);
static cl::opt<bool> PrintNoAlias("print-no-aliases", cl::ReallyHidden);
static cl::opt<bool> PrintMayAlias("print-may-aliases", cl::ReallyHidden);
static cl::opt<bool> PrintMustAlias("print-must-aliases", cl::ReallyHidden);
static cl::opt<bool> PrintNoModRef("print-no-modref", cl::ReallyHidden);
static cl::opt<bool> PrintMod("print-mod", cl::ReallyHidden);
static cl::opt<bool> PrintRef("print-ref", cl::ReallyHidden);
static cl::opt<bool> PrintModRef("print-modref", cl::ReallyHidden);
namespace {
class VISIBILITY_HIDDEN AAEval : public FunctionPass {
unsigned NoAlias, MayAlias, MustAlias;
unsigned NoModRef, Mod, Ref, ModRef;
public:
static char ID; // Pass identification, replacement for typeid
AAEval() : FunctionPass((intptr_t)&ID) {}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<AliasAnalysis>();
AU.setPreservesAll();
}
bool doInitialization(Module &M) {
NoAlias = MayAlias = MustAlias = 0;
NoModRef = Mod = Ref = ModRef = 0;
if (PrintAll) {
PrintNoAlias = PrintMayAlias = PrintMustAlias = true;
PrintNoModRef = PrintMod = PrintRef = PrintModRef = true;
}
return false;
}
bool runOnFunction(Function &F);
bool doFinalization(Module &M);
};
}
char AAEval::ID = 0;
static RegisterPass<AAEval>
X("aa-eval", "Exhaustive Alias Analysis Precision Evaluator", false, true);
FunctionPass *llvm::createAAEvalPass() { return new AAEval(); }
static void PrintResults(const char *Msg, bool P, const Value *V1, const Value *V2,
const Module *M) {
if (P) {
std::stringstream s1, s2;
WriteAsOperand(s1, V1, true, M);
WriteAsOperand(s2, V2, true, M);
std::string o1(s1.str()), o2(s2.str());
if (o2 < o1)
std::swap(o1, o2);
cerr << " " << Msg << ":\t"
<< o1 << ", "
<< o2 << "\n";
}
}
static inline void
PrintModRefResults(const char *Msg, bool P, Instruction *I, Value *Ptr,
Module *M) {
if (P) {
cerr << " " << Msg << ": Ptr: ";
WriteAsOperand(*cerr.stream(), Ptr, true, M);
cerr << "\t<->" << *I;
}
}
bool AAEval::runOnFunction(Function &F) {
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
const TargetData &TD = AA.getTargetData();
std::set<Value *> Pointers;
std::set<CallSite> CallSites;
for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
if (isa<PointerType>(I->getType())) // Add all pointer arguments
Pointers.insert(I);
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
if (isa<PointerType>(I->getType())) // Add all pointer instructions
Pointers.insert(&*I);
Instruction &Inst = *I;
User::op_iterator OI = Inst.op_begin();
if ((isa<InvokeInst>(Inst) || isa<CallInst>(Inst)) &&
isa<Function>(Inst.getOperand(0)))
++OI; // Skip actual functions for direct function calls.
for (; OI != Inst.op_end(); ++OI)
if (isa<PointerType>((*OI)->getType()) && !isa<ConstantPointerNull>(*OI))
Pointers.insert(*OI);
CallSite CS = CallSite::get(&*I);
if (CS.getInstruction()) CallSites.insert(CS);
}
if (PrintNoAlias || PrintMayAlias || PrintMustAlias ||
PrintNoModRef || PrintMod || PrintRef || PrintModRef)
cerr << "Function: " << F.getName() << ": " << Pointers.size()
<< " pointers, " << CallSites.size() << " call sites\n";
// iterate over the worklist, and run the full (n^2)/2 disambiguations
for (std::set<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
I1 != E; ++I1) {
unsigned I1Size = 0;
const Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
if (I1ElTy->isSized()) I1Size = TD.getTypeStoreSize(I1ElTy);
for (std::set<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
unsigned I2Size = 0;
const Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType();
if (I2ElTy->isSized()) I2Size = TD.getTypeStoreSize(I2ElTy);
switch (AA.alias(*I1, I1Size, *I2, I2Size)) {
case AliasAnalysis::NoAlias:
PrintResults("NoAlias", PrintNoAlias, *I1, *I2, F.getParent());
++NoAlias; break;
case AliasAnalysis::MayAlias:
PrintResults("MayAlias", PrintMayAlias, *I1, *I2, F.getParent());
++MayAlias; break;
case AliasAnalysis::MustAlias:
PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent());
++MustAlias; break;
default:
cerr << "Unknown alias query result!\n";
}
}
}
// Mod/ref alias analysis: compare all pairs of calls and values
for (std::set<CallSite>::iterator C = CallSites.begin(),
Ce = CallSites.end(); C != Ce; ++C) {
Instruction *I = C->getInstruction();
for (std::set<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end();
V != Ve; ++V) {
unsigned Size = 0;
const Type *ElTy = cast<PointerType>((*V)->getType())->getElementType();
if (ElTy->isSized()) Size = TD.getTypeStoreSize(ElTy);
switch (AA.getModRefInfo(*C, *V, Size)) {
case AliasAnalysis::NoModRef:
PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent());
++NoModRef; break;
case AliasAnalysis::Mod:
PrintModRefResults(" Mod", PrintMod, I, *V, F.getParent());
++Mod; break;
case AliasAnalysis::Ref:
PrintModRefResults(" Ref", PrintRef, I, *V, F.getParent());
++Ref; break;
case AliasAnalysis::ModRef:
PrintModRefResults(" ModRef", PrintModRef, I, *V, F.getParent());
++ModRef; break;
default:
cerr << "Unknown alias query result!\n";
}
}
}
return false;
}
static void PrintPercent(unsigned Num, unsigned Sum) {
cerr << "(" << Num*100ULL/Sum << "."
<< ((Num*1000ULL/Sum) % 10) << "%)\n";
}
bool AAEval::doFinalization(Module &M) {
unsigned AliasSum = NoAlias + MayAlias + MustAlias;
cerr << "===== Alias Analysis Evaluator Report =====\n";
if (AliasSum == 0) {
cerr << " Alias Analysis Evaluator Summary: No pointers!\n";
} else {
cerr << " " << AliasSum << " Total Alias Queries Performed\n";
cerr << " " << NoAlias << " no alias responses ";
PrintPercent(NoAlias, AliasSum);
cerr << " " << MayAlias << " may alias responses ";
PrintPercent(MayAlias, AliasSum);
cerr << " " << MustAlias << " must alias responses ";
PrintPercent(MustAlias, AliasSum);
cerr << " Alias Analysis Evaluator Pointer Alias Summary: "
<< NoAlias*100/AliasSum << "%/" << MayAlias*100/AliasSum << "%/"
<< MustAlias*100/AliasSum << "%\n";
}
// Display the summary for mod/ref analysis
unsigned ModRefSum = NoModRef + Mod + Ref + ModRef;
if (ModRefSum == 0) {
cerr << " Alias Analysis Mod/Ref Evaluator Summary: no mod/ref!\n";
} else {
cerr << " " << ModRefSum << " Total ModRef Queries Performed\n";
cerr << " " << NoModRef << " no mod/ref responses ";
PrintPercent(NoModRef, ModRefSum);
cerr << " " << Mod << " mod responses ";
PrintPercent(Mod, ModRefSum);
cerr << " " << Ref << " ref responses ";
PrintPercent(Ref, ModRefSum);
cerr << " " << ModRef << " mod & ref responses ";
PrintPercent(ModRef, ModRefSum);
cerr << " Alias Analysis Evaluator Mod/Ref Summary: "
<< NoModRef*100/ModRefSum << "%/" << Mod*100/ModRefSum << "%/"
<< Ref*100/ModRefSum << "%/" << ModRef*100/ModRefSum << "%\n";
}
return false;
}