llvm-6502/lib/Analysis/AliasAnalysisEvaluator.cpp
Chandler Carruth 876ac60880 [Modules] Move InstIterator out of the Support library, where it had no
business.

This header includes Function and BasicBlock and directly uses the
interfaces of both classes. It has to do with the IR, it even has that
in the name. =] Put it in the library it belongs to.

This is one step toward making LLVM's Support library survive a C++
modules bootstrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202814 91177308-0d34-0410-b5e6-96231b3b80d8
2014-03-04 10:30:26 +00:00

372 lines
14 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/Analysis/Passes.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
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> PrintPartialAlias("print-partial-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);
static cl::opt<bool> EvalTBAA("evaluate-tbaa", cl::ReallyHidden);
namespace {
class AAEval : public FunctionPass {
unsigned NoAlias, MayAlias, PartialAlias, MustAlias;
unsigned NoModRef, Mod, Ref, ModRef;
public:
static char ID; // Pass identification, replacement for typeid
AAEval() : FunctionPass(ID) {
initializeAAEvalPass(*PassRegistry::getPassRegistry());
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<AliasAnalysis>();
AU.setPreservesAll();
}
bool doInitialization(Module &M) {
NoAlias = MayAlias = PartialAlias = MustAlias = 0;
NoModRef = Mod = Ref = ModRef = 0;
if (PrintAll) {
PrintNoAlias = PrintMayAlias = true;
PrintPartialAlias = PrintMustAlias = true;
PrintNoModRef = PrintMod = PrintRef = PrintModRef = true;
}
return false;
}
bool runOnFunction(Function &F);
bool doFinalization(Module &M);
};
}
char AAEval::ID = 0;
INITIALIZE_PASS_BEGIN(AAEval, "aa-eval",
"Exhaustive Alias Analysis Precision Evaluator", false, true)
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
INITIALIZE_PASS_END(AAEval, "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::string o1, o2;
{
raw_string_ostream os1(o1), os2(o2);
V1->printAsOperand(os1, true, M);
V2->printAsOperand(os2, true, M);
}
if (o2 < o1)
std::swap(o1, o2);
errs() << " " << Msg << ":\t"
<< o1 << ", "
<< o2 << "\n";
}
}
static inline void
PrintModRefResults(const char *Msg, bool P, Instruction *I, Value *Ptr,
Module *M) {
if (P) {
errs() << " " << Msg << ": Ptr: ";
Ptr->printAsOperand(errs(), true, M);
errs() << "\t<->" << *I << '\n';
}
}
static inline void
PrintModRefResults(const char *Msg, bool P, CallSite CSA, CallSite CSB,
Module *M) {
if (P) {
errs() << " " << Msg << ": " << *CSA.getInstruction()
<< " <-> " << *CSB.getInstruction() << '\n';
}
}
static inline void
PrintLoadStoreResults(const char *Msg, bool P, const Value *V1,
const Value *V2, const Module *M) {
if (P) {
errs() << " " << Msg << ": " << *V1
<< " <-> " << *V2 << '\n';
}
}
static inline bool isInterestingPointer(Value *V) {
return V->getType()->isPointerTy()
&& !isa<ConstantPointerNull>(V);
}
bool AAEval::runOnFunction(Function &F) {
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
SetVector<Value *> Pointers;
SetVector<CallSite> CallSites;
SetVector<Value *> Loads;
SetVector<Value *> Stores;
for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; ++I)
if (I->getType()->isPointerTy()) // Add all pointer arguments.
Pointers.insert(I);
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) {
if (I->getType()->isPointerTy()) // Add all pointer instructions.
Pointers.insert(&*I);
if (EvalTBAA && isa<LoadInst>(&*I))
Loads.insert(&*I);
if (EvalTBAA && isa<StoreInst>(&*I))
Stores.insert(&*I);
Instruction &Inst = *I;
if (CallSite CS = cast<Value>(&Inst)) {
Value *Callee = CS.getCalledValue();
// Skip actual functions for direct function calls.
if (!isa<Function>(Callee) && isInterestingPointer(Callee))
Pointers.insert(Callee);
// Consider formals.
for (CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
AI != AE; ++AI)
if (isInterestingPointer(*AI))
Pointers.insert(*AI);
CallSites.insert(CS);
} else {
// Consider all operands.
for (Instruction::op_iterator OI = Inst.op_begin(), OE = Inst.op_end();
OI != OE; ++OI)
if (isInterestingPointer(*OI))
Pointers.insert(*OI);
}
}
if (PrintNoAlias || PrintMayAlias || PrintPartialAlias || PrintMustAlias ||
PrintNoModRef || PrintMod || PrintRef || PrintModRef)
errs() << "Function: " << F.getName() << ": " << Pointers.size()
<< " pointers, " << CallSites.size() << " call sites\n";
// iterate over the worklist, and run the full (n^2)/2 disambiguations
for (SetVector<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end();
I1 != E; ++I1) {
uint64_t I1Size = AliasAnalysis::UnknownSize;
Type *I1ElTy = cast<PointerType>((*I1)->getType())->getElementType();
if (I1ElTy->isSized()) I1Size = AA.getTypeStoreSize(I1ElTy);
for (SetVector<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) {
uint64_t I2Size = AliasAnalysis::UnknownSize;
Type *I2ElTy =cast<PointerType>((*I2)->getType())->getElementType();
if (I2ElTy->isSized()) I2Size = AA.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::PartialAlias:
PrintResults("PartialAlias", PrintPartialAlias, *I1, *I2,
F.getParent());
++PartialAlias; break;
case AliasAnalysis::MustAlias:
PrintResults("MustAlias", PrintMustAlias, *I1, *I2, F.getParent());
++MustAlias; break;
}
}
}
if (EvalTBAA) {
// iterate over all pairs of load, store
for (SetVector<Value *>::iterator I1 = Loads.begin(), E = Loads.end();
I1 != E; ++I1) {
for (SetVector<Value *>::iterator I2 = Stores.begin(), E2 = Stores.end();
I2 != E2; ++I2) {
switch (AA.alias(AA.getLocation(cast<LoadInst>(*I1)),
AA.getLocation(cast<StoreInst>(*I2)))) {
case AliasAnalysis::NoAlias:
PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2,
F.getParent());
++NoAlias; break;
case AliasAnalysis::MayAlias:
PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2,
F.getParent());
++MayAlias; break;
case AliasAnalysis::PartialAlias:
PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2,
F.getParent());
++PartialAlias; break;
case AliasAnalysis::MustAlias:
PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2,
F.getParent());
++MustAlias; break;
}
}
}
// iterate over all pairs of store, store
for (SetVector<Value *>::iterator I1 = Stores.begin(), E = Stores.end();
I1 != E; ++I1) {
for (SetVector<Value *>::iterator I2 = Stores.begin(); I2 != I1; ++I2) {
switch (AA.alias(AA.getLocation(cast<StoreInst>(*I1)),
AA.getLocation(cast<StoreInst>(*I2)))) {
case AliasAnalysis::NoAlias:
PrintLoadStoreResults("NoAlias", PrintNoAlias, *I1, *I2,
F.getParent());
++NoAlias; break;
case AliasAnalysis::MayAlias:
PrintLoadStoreResults("MayAlias", PrintMayAlias, *I1, *I2,
F.getParent());
++MayAlias; break;
case AliasAnalysis::PartialAlias:
PrintLoadStoreResults("PartialAlias", PrintPartialAlias, *I1, *I2,
F.getParent());
++PartialAlias; break;
case AliasAnalysis::MustAlias:
PrintLoadStoreResults("MustAlias", PrintMustAlias, *I1, *I2,
F.getParent());
++MustAlias; break;
}
}
}
}
// Mod/ref alias analysis: compare all pairs of calls and values
for (SetVector<CallSite>::iterator C = CallSites.begin(),
Ce = CallSites.end(); C != Ce; ++C) {
Instruction *I = C->getInstruction();
for (SetVector<Value *>::iterator V = Pointers.begin(), Ve = Pointers.end();
V != Ve; ++V) {
uint64_t Size = AliasAnalysis::UnknownSize;
Type *ElTy = cast<PointerType>((*V)->getType())->getElementType();
if (ElTy->isSized()) Size = AA.getTypeStoreSize(ElTy);
switch (AA.getModRefInfo(*C, *V, Size)) {
case AliasAnalysis::NoModRef:
PrintModRefResults("NoModRef", PrintNoModRef, I, *V, F.getParent());
++NoModRef; break;
case AliasAnalysis::Mod:
PrintModRefResults("Just Mod", PrintMod, I, *V, F.getParent());
++Mod; break;
case AliasAnalysis::Ref:
PrintModRefResults("Just Ref", PrintRef, I, *V, F.getParent());
++Ref; break;
case AliasAnalysis::ModRef:
PrintModRefResults("Both ModRef", PrintModRef, I, *V, F.getParent());
++ModRef; break;
}
}
}
// Mod/ref alias analysis: compare all pairs of calls
for (SetVector<CallSite>::iterator C = CallSites.begin(),
Ce = CallSites.end(); C != Ce; ++C) {
for (SetVector<CallSite>::iterator D = CallSites.begin(); D != Ce; ++D) {
if (D == C)
continue;
switch (AA.getModRefInfo(*C, *D)) {
case AliasAnalysis::NoModRef:
PrintModRefResults("NoModRef", PrintNoModRef, *C, *D, F.getParent());
++NoModRef; break;
case AliasAnalysis::Mod:
PrintModRefResults("Just Mod", PrintMod, *C, *D, F.getParent());
++Mod; break;
case AliasAnalysis::Ref:
PrintModRefResults("Just Ref", PrintRef, *C, *D, F.getParent());
++Ref; break;
case AliasAnalysis::ModRef:
PrintModRefResults("Both ModRef", PrintModRef, *C, *D, F.getParent());
++ModRef; break;
}
}
}
return false;
}
static void PrintPercent(unsigned Num, unsigned Sum) {
errs() << "(" << Num*100ULL/Sum << "."
<< ((Num*1000ULL/Sum) % 10) << "%)\n";
}
bool AAEval::doFinalization(Module &M) {
unsigned AliasSum = NoAlias + MayAlias + PartialAlias + MustAlias;
errs() << "===== Alias Analysis Evaluator Report =====\n";
if (AliasSum == 0) {
errs() << " Alias Analysis Evaluator Summary: No pointers!\n";
} else {
errs() << " " << AliasSum << " Total Alias Queries Performed\n";
errs() << " " << NoAlias << " no alias responses ";
PrintPercent(NoAlias, AliasSum);
errs() << " " << MayAlias << " may alias responses ";
PrintPercent(MayAlias, AliasSum);
errs() << " " << PartialAlias << " partial alias responses ";
PrintPercent(PartialAlias, AliasSum);
errs() << " " << MustAlias << " must alias responses ";
PrintPercent(MustAlias, AliasSum);
errs() << " Alias Analysis Evaluator Pointer Alias Summary: "
<< NoAlias*100/AliasSum << "%/" << MayAlias*100/AliasSum << "%/"
<< PartialAlias*100/AliasSum << "%/"
<< MustAlias*100/AliasSum << "%\n";
}
// Display the summary for mod/ref analysis
unsigned ModRefSum = NoModRef + Mod + Ref + ModRef;
if (ModRefSum == 0) {
errs() << " Alias Analysis Mod/Ref Evaluator Summary: no mod/ref!\n";
} else {
errs() << " " << ModRefSum << " Total ModRef Queries Performed\n";
errs() << " " << NoModRef << " no mod/ref responses ";
PrintPercent(NoModRef, ModRefSum);
errs() << " " << Mod << " mod responses ";
PrintPercent(Mod, ModRefSum);
errs() << " " << Ref << " ref responses ";
PrintPercent(Ref, ModRefSum);
errs() << " " << ModRef << " mod & ref responses ";
PrintPercent(ModRef, ModRefSum);
errs() << " Alias Analysis Evaluator Mod/Ref Summary: "
<< NoModRef*100/ModRefSum << "%/" << Mod*100/ModRefSum << "%/"
<< Ref*100/ModRefSum << "%/" << ModRef*100/ModRefSum << "%\n";
}
return false;
}