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llvm-project/llvm/lib/Analysis/AliasSetTracker.cpp

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//===- AliasSetTracker.cpp - Alias Sets Tracker implementation-------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the AliasSetTracker and AliasSet classes.
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/AliasSetTracker.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/MemoryLocation.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instruction.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Value.h"
#include "llvm/Pass.h"
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdint>
#include <vector>
using namespace llvm;
static cl::opt<unsigned>
SaturationThreshold("alias-set-saturation-threshold", cl::Hidden,
cl::init(250),
cl::desc("The maximum number of pointers may-alias "
"sets may contain before degradation"));
/// mergeSetIn - Merge the specified alias set into this alias set.
///
void AliasSet::mergeSetIn(AliasSet &AS, AliasSetTracker &AST) {
assert(!AS.Forward && "Alias set is already forwarding!");
assert(!Forward && "This set is a forwarding set!!");
bool WasMustAlias = (Alias == SetMustAlias);
// Update the alias and access types of this set...
Access |= AS.Access;
Alias |= AS.Alias;
Volatile |= AS.Volatile;
if (Alias == SetMustAlias) {
// Check that these two merged sets really are must aliases. Since both
// used to be must-alias sets, we can just check any pointer from each set
// for aliasing.
AliasAnalysis &AA = AST.getAliasAnalysis();
PointerRec *L = getSomePointer();
PointerRec *R = AS.getSomePointer();
// If the pointers are not a must-alias pair, this set becomes a may alias.
if (AA.alias(MemoryLocation(L->getValue(), L->getSize(), L->getAAInfo()),
MemoryLocation(R->getValue(), R->getSize(), R->getAAInfo())) !=
MustAlias)
Alias = SetMayAlias;
}
if (Alias == SetMayAlias) {
if (WasMustAlias)
AST.TotalMayAliasSetSize += size();
if (AS.Alias == SetMustAlias)
AST.TotalMayAliasSetSize += AS.size();
}
bool ASHadUnknownInsts = !AS.UnknownInsts.empty();
if (UnknownInsts.empty()) { // Merge call sites...
if (ASHadUnknownInsts) {
std::swap(UnknownInsts, AS.UnknownInsts);
addRef();
}
} else if (ASHadUnknownInsts) {
UnknownInsts.insert(UnknownInsts.end(), AS.UnknownInsts.begin(), AS.UnknownInsts.end());
AS.UnknownInsts.clear();
}
AS.Forward = this; // Forward across AS now...
addRef(); // AS is now pointing to us...
// Merge the list of constituent pointers...
if (AS.PtrList) {
SetSize += AS.size();
AS.SetSize = 0;
*PtrListEnd = AS.PtrList;
AS.PtrList->setPrevInList(PtrListEnd);
PtrListEnd = AS.PtrListEnd;
AS.PtrList = nullptr;
AS.PtrListEnd = &AS.PtrList;
assert(*AS.PtrListEnd == nullptr && "End of list is not null?");
}
if (ASHadUnknownInsts)
AS.dropRef(AST);
}
void AliasSetTracker::removeAliasSet(AliasSet *AS) {
if (AliasSet *Fwd = AS->Forward) {
Fwd->dropRef(*this);
AS->Forward = nullptr;
}
if (AS->Alias == AliasSet::SetMayAlias)
TotalMayAliasSetSize -= AS->size();
AliasSets.erase(AS);
}
void AliasSet::removeFromTracker(AliasSetTracker &AST) {
assert(RefCount == 0 && "Cannot remove non-dead alias set from tracker!");
AST.removeAliasSet(this);
}
void AliasSet::addPointer(AliasSetTracker &AST, PointerRec &Entry,
uint64_t Size, const AAMDNodes &AAInfo,
bool KnownMustAlias) {
assert(!Entry.hasAliasSet() && "Entry already in set!");
// Check to see if we have to downgrade to _may_ alias.
if (isMustAlias() && !KnownMustAlias)
if (PointerRec *P = getSomePointer()) {
AliasAnalysis &AA = AST.getAliasAnalysis();
AliasResult Result =
AA.alias(MemoryLocation(P->getValue(), P->getSize(), P->getAAInfo()),
MemoryLocation(Entry.getValue(), Size, AAInfo));
if (Result != MustAlias) {
Alias = SetMayAlias;
AST.TotalMayAliasSetSize += size();
} else {
// First entry of must alias must have maximum size!
P->updateSizeAndAAInfo(Size, AAInfo);
}
assert(Result != NoAlias && "Cannot be part of must set!");
}
Entry.setAliasSet(this);
Entry.updateSizeAndAAInfo(Size, AAInfo);
// Add it to the end of the list...
++SetSize;
assert(*PtrListEnd == nullptr && "End of list is not null?");
*PtrListEnd = &Entry;
PtrListEnd = Entry.setPrevInList(PtrListEnd);
assert(*PtrListEnd == nullptr && "End of list is not null?");
// Entry points to alias set.
addRef();
if (Alias == SetMayAlias)
AST.TotalMayAliasSetSize++;
}
void AliasSet::addUnknownInst(Instruction *I, AliasAnalysis &AA) {
if (UnknownInsts.empty())
addRef();
UnknownInsts.emplace_back(I);
if (!I->mayWriteToMemory()) {
Alias = SetMayAlias;
Access |= RefAccess;
return;
}
// FIXME: This should use mod/ref information to make this not suck so bad
Alias = SetMayAlias;
Access = ModRefAccess;
}
/// aliasesPointer - Return true if the specified pointer "may" (or must)
/// alias one of the members in the set.
///
bool AliasSet::aliasesPointer(const Value *Ptr, uint64_t Size,
const AAMDNodes &AAInfo,
AliasAnalysis &AA) const {
if (AliasAny)
return true;
if (Alias == SetMustAlias) {
assert(UnknownInsts.empty() && "Illegal must alias set!");
// If this is a set of MustAliases, only check to see if the pointer aliases
// SOME value in the set.
PointerRec *SomePtr = getSomePointer();
assert(SomePtr && "Empty must-alias set??");
return AA.alias(MemoryLocation(SomePtr->getValue(), SomePtr->getSize(),
SomePtr->getAAInfo()),
MemoryLocation(Ptr, Size, AAInfo));
}
// If this is a may-alias set, we have to check all of the pointers in the set
// to be sure it doesn't alias the set...
for (iterator I = begin(), E = end(); I != E; ++I)
if (AA.alias(MemoryLocation(Ptr, Size, AAInfo),
MemoryLocation(I.getPointer(), I.getSize(), I.getAAInfo())))
return true;
// Check the unknown instructions...
if (!UnknownInsts.empty()) {
for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i)
if (auto *Inst = getUnknownInst(i))
if (AA.getModRefInfo(Inst, MemoryLocation(Ptr, Size, AAInfo)) !=
MRI_NoModRef)
return true;
}
return false;
}
bool AliasSet::aliasesUnknownInst(const Instruction *Inst,
AliasAnalysis &AA) const {
if (AliasAny)
return true;
if (!Inst->mayReadOrWriteMemory())
return false;
for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) {
if (auto *UnknownInst = getUnknownInst(i)) {
ImmutableCallSite C1(UnknownInst), C2(Inst);
if (!C1 || !C2 || AA.getModRefInfo(C1, C2) != MRI_NoModRef ||
AA.getModRefInfo(C2, C1) != MRI_NoModRef)
return true;
}
}
for (iterator I = begin(), E = end(); I != E; ++I)
if (AA.getModRefInfo(Inst, MemoryLocation(I.getPointer(), I.getSize(),
I.getAAInfo())) != MRI_NoModRef)
return true;
return false;
}
void AliasSetTracker::clear() {
// Delete all the PointerRec entries.
for (PointerMapType::iterator I = PointerMap.begin(), E = PointerMap.end();
I != E; ++I)
I->second->eraseFromList();
PointerMap.clear();
// The alias sets should all be clear now.
AliasSets.clear();
}
/// mergeAliasSetsForPointer - Given a pointer, merge all alias sets that may
/// alias the pointer. Return the unified set, or nullptr if no set that aliases
/// the pointer was found.
AliasSet *AliasSetTracker::mergeAliasSetsForPointer(const Value *Ptr,
uint64_t Size,
const AAMDNodes &AAInfo) {
AliasSet *FoundSet = nullptr;
for (iterator I = begin(), E = end(); I != E;) {
iterator Cur = I++;
if (Cur->Forward || !Cur->aliasesPointer(Ptr, Size, AAInfo, AA)) continue;
if (!FoundSet) { // If this is the first alias set ptr can go into.
FoundSet = &*Cur; // Remember it.
} else { // Otherwise, we must merge the sets.
FoundSet->mergeSetIn(*Cur, *this); // Merge in contents.
}
}
return FoundSet;
}
bool AliasSetTracker::containsUnknown(const Instruction *Inst) const {
for (const AliasSet &AS : *this)
if (!AS.Forward && AS.aliasesUnknownInst(Inst, AA))
return true;
return false;
}
AliasSet *AliasSetTracker::findAliasSetForUnknownInst(Instruction *Inst) {
AliasSet *FoundSet = nullptr;
for (iterator I = begin(), E = end(); I != E;) {
iterator Cur = I++;
if (Cur->Forward || !Cur->aliasesUnknownInst(Inst, AA))
continue;
if (!FoundSet) // If this is the first alias set ptr can go into.
FoundSet = &*Cur; // Remember it.
else if (!Cur->Forward) // Otherwise, we must merge the sets.
FoundSet->mergeSetIn(*Cur, *this); // Merge in contents.
}
return FoundSet;
}
/// getAliasSetForPointer - Return the alias set that the specified pointer
/// lives in.
AliasSet &AliasSetTracker::getAliasSetForPointer(Value *Pointer, uint64_t Size,
const AAMDNodes &AAInfo) {
AliasSet::PointerRec &Entry = getEntryFor(Pointer);
if (AliasAnyAS) {
// At this point, the AST is saturated, so we only have one active alias
// set. That means we already know which alias set we want to return, and
// just need to add the pointer to that set to keep the data structure
// consistent.
// This, of course, means that we will never need a merge here.
if (Entry.hasAliasSet()) {
Entry.updateSizeAndAAInfo(Size, AAInfo);
assert(Entry.getAliasSet(*this) == AliasAnyAS &&
"Entry in saturated AST must belong to only alias set");
} else {
AliasAnyAS->addPointer(*this, Entry, Size, AAInfo);
}
return *AliasAnyAS;
}
// Check to see if the pointer is already known.
if (Entry.hasAliasSet()) {
// If the size changed, we may need to merge several alias sets.
// Note that we can *not* return the result of mergeAliasSetsForPointer
// due to a quirk of alias analysis behavior. Since alias(undef, undef)
// is NoAlias, mergeAliasSetsForPointer(undef, ...) will not find the
// the right set for undef, even if it exists.
if (Entry.updateSizeAndAAInfo(Size, AAInfo))
mergeAliasSetsForPointer(Pointer, Size, AAInfo);
// Return the set!
return *Entry.getAliasSet(*this)->getForwardedTarget(*this);
}
if (AliasSet *AS = mergeAliasSetsForPointer(Pointer, Size, AAInfo)) {
// Add it to the alias set it aliases.
AS->addPointer(*this, Entry, Size, AAInfo);
return *AS;
}
// Otherwise create a new alias set to hold the loaded pointer.
AliasSets.push_back(new AliasSet());
AliasSets.back().addPointer(*this, Entry, Size, AAInfo);
return AliasSets.back();
}
void AliasSetTracker::add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo) {
addPointer(Ptr, Size, AAInfo, AliasSet::NoAccess);
}
void AliasSetTracker::add(LoadInst *LI) {
if (isStrongerThanMonotonic(LI->getOrdering())) return addUnknown(LI);
AAMDNodes AAInfo;
LI->getAAMetadata(AAInfo);
AliasSet::AccessLattice Access = AliasSet::RefAccess;
const DataLayout &DL = LI->getModule()->getDataLayout();
AliasSet &AS = addPointer(LI->getOperand(0),
DL.getTypeStoreSize(LI->getType()), AAInfo, Access);
if (LI->isVolatile()) AS.setVolatile();
}
void AliasSetTracker::add(StoreInst *SI) {
if (isStrongerThanMonotonic(SI->getOrdering())) return addUnknown(SI);
AAMDNodes AAInfo;
SI->getAAMetadata(AAInfo);
AliasSet::AccessLattice Access = AliasSet::ModAccess;
const DataLayout &DL = SI->getModule()->getDataLayout();
Value *Val = SI->getOperand(0);
AliasSet &AS = addPointer(
SI->getOperand(1), DL.getTypeStoreSize(Val->getType()), AAInfo, Access);
if (SI->isVolatile()) AS.setVolatile();
}
void AliasSetTracker::add(VAArgInst *VAAI) {
AAMDNodes AAInfo;
VAAI->getAAMetadata(AAInfo);
addPointer(VAAI->getOperand(0), MemoryLocation::UnknownSize, AAInfo,
AliasSet::ModRefAccess);
}
void AliasSetTracker::add(MemSetInst *MSI) {
AAMDNodes AAInfo;
MSI->getAAMetadata(AAInfo);
uint64_t Len;
if (ConstantInt *C = dyn_cast<ConstantInt>(MSI->getLength()))
Len = C->getZExtValue();
else
Len = MemoryLocation::UnknownSize;
AliasSet &AS =
addPointer(MSI->getRawDest(), Len, AAInfo, AliasSet::ModAccess);
if (MSI->isVolatile())
AS.setVolatile();
}
void AliasSetTracker::add(MemTransferInst *MTI) {
AAMDNodes AAInfo;
MTI->getAAMetadata(AAInfo);
uint64_t Len;
if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength()))
Len = C->getZExtValue();
else
Len = MemoryLocation::UnknownSize;
AliasSet &ASSrc =
addPointer(MTI->getRawSource(), Len, AAInfo, AliasSet::RefAccess);
if (MTI->isVolatile())
ASSrc.setVolatile();
AliasSet &ASDst =
addPointer(MTI->getRawDest(), Len, AAInfo, AliasSet::ModAccess);
if (MTI->isVolatile())
ASDst.setVolatile();
}
void AliasSetTracker::addUnknown(Instruction *Inst) {
if (isa<DbgInfoIntrinsic>(Inst))
return; // Ignore DbgInfo Intrinsics.
if (auto *II = dyn_cast<IntrinsicInst>(Inst)) {
// These intrinsics will show up as affecting memory, but they are just
// markers.
switch (II->getIntrinsicID()) {
default:
break;
// FIXME: Add lifetime/invariant intrinsics (See: PR30807).
case Intrinsic::assume:
return;
}
}
if (!Inst->mayReadOrWriteMemory())
return; // doesn't alias anything
AliasSet *AS = findAliasSetForUnknownInst(Inst);
if (AS) {
AS->addUnknownInst(Inst, AA);
return;
}
AliasSets.push_back(new AliasSet());
AS = &AliasSets.back();
AS->addUnknownInst(Inst, AA);
}
void AliasSetTracker::add(Instruction *I) {
// Dispatch to one of the other add methods.
if (LoadInst *LI = dyn_cast<LoadInst>(I))
return add(LI);
if (StoreInst *SI = dyn_cast<StoreInst>(I))
return add(SI);
if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
return add(VAAI);
if (MemSetInst *MSI = dyn_cast<MemSetInst>(I))
return add(MSI);
if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(I))
return add(MTI);
return addUnknown(I);
}
void AliasSetTracker::add(BasicBlock &BB) {
for (auto &I : BB)
add(&I);
}
void AliasSetTracker::add(const AliasSetTracker &AST) {
assert(&AA == &AST.AA &&
"Merging AliasSetTracker objects with different Alias Analyses!");
// Loop over all of the alias sets in AST, adding the pointers contained
// therein into the current alias sets. This can cause alias sets to be
// merged together in the current AST.
for (const AliasSet &AS : AST) {
if (AS.Forward)
continue; // Ignore forwarding alias sets
// If there are any call sites in the alias set, add them to this AST.
for (unsigned i = 0, e = AS.UnknownInsts.size(); i != e; ++i)
if (auto *Inst = AS.getUnknownInst(i))
add(Inst);
// Loop over all of the pointers in this alias set.
for (AliasSet::iterator ASI = AS.begin(), E = AS.end(); ASI != E; ++ASI) {
AliasSet &NewAS =
addPointer(ASI.getPointer(), ASI.getSize(), ASI.getAAInfo(),
(AliasSet::AccessLattice)AS.Access);
if (AS.isVolatile()) NewAS.setVolatile();
}
}
}
// deleteValue method - This method is used to remove a pointer value from the
// AliasSetTracker entirely. It should be used when an instruction is deleted
// from the program to update the AST. If you don't use this, you would have
// dangling pointers to deleted instructions.
//
void AliasSetTracker::deleteValue(Value *PtrVal) {
// First, look up the PointerRec for this pointer.
PointerMapType::iterator I = PointerMap.find_as(PtrVal);
if (I == PointerMap.end()) return; // Noop
// If we found one, remove the pointer from the alias set it is in.
AliasSet::PointerRec *PtrValEnt = I->second;
AliasSet *AS = PtrValEnt->getAliasSet(*this);
// Unlink and delete from the list of values.
PtrValEnt->eraseFromList();
if (AS->Alias == AliasSet::SetMayAlias) {
AS->SetSize--;
TotalMayAliasSetSize--;
}
// Stop using the alias set.
AS->dropRef(*this);
PointerMap.erase(I);
}
// copyValue - This method should be used whenever a preexisting value in the
// program is copied or cloned, introducing a new value. Note that it is ok for
// clients that use this method to introduce the same value multiple times: if
// the tracker already knows about a value, it will ignore the request.
//
void AliasSetTracker::copyValue(Value *From, Value *To) {
// First, look up the PointerRec for this pointer.
PointerMapType::iterator I = PointerMap.find_as(From);
if (I == PointerMap.end())
return; // Noop
assert(I->second->hasAliasSet() && "Dead entry?");
AliasSet::PointerRec &Entry = getEntryFor(To);
if (Entry.hasAliasSet()) return; // Already in the tracker!
// getEntryFor above may invalidate iterator \c I, so reinitialize it.
I = PointerMap.find_as(From);
// Add it to the alias set it aliases...
AliasSet *AS = I->second->getAliasSet(*this);
AS->addPointer(*this, Entry, I->second->getSize(),
I->second->getAAInfo(),
true);
}
AliasSet &AliasSetTracker::mergeAllAliasSets() {
assert(!AliasAnyAS && (TotalMayAliasSetSize > SaturationThreshold) &&
"Full merge should happen once, when the saturation threshold is "
"reached");
// Collect all alias sets, so that we can drop references with impunity
// without worrying about iterator invalidation.
std::vector<AliasSet *> ASVector;
ASVector.reserve(SaturationThreshold);
for (iterator I = begin(), E = end(); I != E; I++)
ASVector.push_back(&*I);
// Copy all instructions and pointers into a new set, and forward all other
// sets to it.
AliasSets.push_back(new AliasSet());
AliasAnyAS = &AliasSets.back();
AliasAnyAS->Alias = AliasSet::SetMayAlias;
AliasAnyAS->Access = AliasSet::ModRefAccess;
AliasAnyAS->AliasAny = true;
for (auto Cur : ASVector) {
// If Cur was already forwarding, just forward to the new AS instead.
AliasSet *FwdTo = Cur->Forward;
if (FwdTo) {
Cur->Forward = AliasAnyAS;
AliasAnyAS->addRef();
FwdTo->dropRef(*this);
continue;
}
// Otherwise, perform the actual merge.
AliasAnyAS->mergeSetIn(*Cur, *this);
}
return *AliasAnyAS;
}
AliasSet &AliasSetTracker::addPointer(Value *P, uint64_t Size,
const AAMDNodes &AAInfo,
AliasSet::AccessLattice E) {
AliasSet &AS = getAliasSetForPointer(P, Size, AAInfo);
AS.Access |= E;
if (!AliasAnyAS && (TotalMayAliasSetSize > SaturationThreshold)) {
// The AST is now saturated. From here on, we conservatively consider all
// pointers to alias each-other.
return mergeAllAliasSets();
}
return AS;
}
//===----------------------------------------------------------------------===//
// AliasSet/AliasSetTracker Printing Support
//===----------------------------------------------------------------------===//
void AliasSet::print(raw_ostream &OS) const {
OS << " AliasSet[" << (const void*)this << ", " << RefCount << "] ";
OS << (Alias == SetMustAlias ? "must" : "may") << " alias, ";
switch (Access) {
case NoAccess: OS << "No access "; break;
case RefAccess: OS << "Ref "; break;
case ModAccess: OS << "Mod "; break;
case ModRefAccess: OS << "Mod/Ref "; break;
default: llvm_unreachable("Bad value for Access!");
}
if (isVolatile()) OS << "[volatile] ";
if (Forward)
OS << " forwarding to " << (void*)Forward;
if (!empty()) {
OS << "Pointers: ";
for (iterator I = begin(), E = end(); I != E; ++I) {
if (I != begin()) OS << ", ";
I.getPointer()->printAsOperand(OS << "(");
OS << ", " << I.getSize() << ")";
}
}
if (!UnknownInsts.empty()) {
OS << "\n " << UnknownInsts.size() << " Unknown instructions: ";
for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) {
if (i) OS << ", ";
if (auto *I = getUnknownInst(i))
I->printAsOperand(OS);
}
}
OS << "\n";
}
void AliasSetTracker::print(raw_ostream &OS) const {
OS << "Alias Set Tracker: " << AliasSets.size() << " alias sets for "
<< PointerMap.size() << " pointer values.\n";
for (const AliasSet &AS : *this)
AS.print(OS);
OS << "\n";
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void AliasSet::dump() const { print(dbgs()); }
LLVM_DUMP_METHOD void AliasSetTracker::dump() const { print(dbgs()); }
#endif
//===----------------------------------------------------------------------===//
// ASTCallbackVH Class Implementation
//===----------------------------------------------------------------------===//
void AliasSetTracker::ASTCallbackVH::deleted() {
assert(AST && "ASTCallbackVH called with a null AliasSetTracker!");
AST->deleteValue(getValPtr());
// this now dangles!
}
void AliasSetTracker::ASTCallbackVH::allUsesReplacedWith(Value *V) {
AST->copyValue(getValPtr(), V);
}
AliasSetTracker::ASTCallbackVH::ASTCallbackVH(Value *V, AliasSetTracker *ast)
: CallbackVH(V), AST(ast) {}
AliasSetTracker::ASTCallbackVH &
AliasSetTracker::ASTCallbackVH::operator=(Value *V) {
return *this = ASTCallbackVH(V, AST);
}
//===----------------------------------------------------------------------===//
// AliasSetPrinter Pass
//===----------------------------------------------------------------------===//
namespace {
class AliasSetPrinter : public FunctionPass {
AliasSetTracker *Tracker;
public:
static char ID; // Pass identification, replacement for typeid
AliasSetPrinter() : FunctionPass(ID) {
initializeAliasSetPrinterPass(*PassRegistry::getPassRegistry());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesAll();
AU.addRequired<AAResultsWrapperPass>();
}
bool runOnFunction(Function &F) override {
auto &AAWP = getAnalysis<AAResultsWrapperPass>();
Tracker = new AliasSetTracker(AAWP.getAAResults());
errs() << "Alias sets for function '" << F.getName() << "':\n";
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
Tracker->add(&*I);
Tracker->print(errs());
delete Tracker;
return false;
}
};
} // end anonymous namespace
char AliasSetPrinter::ID = 0;
INITIALIZE_PASS_BEGIN(AliasSetPrinter, "print-alias-sets",
"Alias Set Printer", false, true)
INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
INITIALIZE_PASS_END(AliasSetPrinter, "print-alias-sets",
"Alias Set Printer", false, true)
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