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_iterator I = AST.begin(), E = AST.end(); I != E; ++I) {
if (I->Forward) continue; // Ignore forwarding alias sets
AliasSet &AS = const_cast<AliasSet&>(*I);
// 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)
add(AS.UnknownInsts[i]);
// Loop over all of the pointers in this alias set.
bool X;
for (AliasSet::iterator ASI = AS.begin(), E = AS.end(); ASI != E; ++ASI) {
AliasSet &NewAS = addPointer(ASI.getPointer(), ASI.getSize(),
ASI.getTBAAInfo(),
(AliasSet::AccessType)AS.AccessTy, X);
if (AS.isVolatile()) NewAS.setVolatile();
}
}
}
/// cloneBasicBlockAnalysis - Simple Analysis hook. Clone alias set info.
void LICM::cloneBasicBlockAnalysis(BasicBlock *From, BasicBlock *To, Loop *L) {
AliasSetTracker *AST = LoopToAliasMap[L];
if (!AST)
return;
AST->copyValue(From, To);
}
/// deleteAnalysisValue - Simple Analysis hook. Delete value V from alias
/// set.
void LICM::deleteAnalysisValue(Value *V, Loop *L) {
AliasSetTracker *AST = LoopToAliasMap[L];
if (!AST)
return;
AST->deleteValue(V);
}
void DeadStoreEliminationPass::printSet(raw_ostream &O,
AliasSetTracker &myset) const {
O << " {\n";
for (AliasSetTracker::const_iterator it = myset.begin();
it != myset.end(); ++it) {
O << " ";
(*it).print(O);
}
O << " }\n";
}
void AliasSet::addPointer(AliasSetTracker &AST, PointerRec &Entry,
uint64_t Size, const MDNode *TBAAInfo,
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();
AliasAnalysis::AliasResult Result =
AA.alias(AliasAnalysis::Location(P->getValue(), P->getSize(),
P->getTBAAInfo()),
AliasAnalysis::Location(Entry.getValue(), Size, TBAAInfo));
if (Result != AliasAnalysis::MustAlias)
AliasTy = MayAlias;
else // First entry of must alias must have maximum size!
P->updateSizeAndTBAAInfo(Size, TBAAInfo);
assert(Result != AliasAnalysis::NoAlias && "Cannot be part of must set!");
}
Entry.setAliasSet(this);
Entry.updateSizeAndTBAAInfo(Size, TBAAInfo);
// Add it to the end of the list...
assert(*PtrListEnd == 0 && "End of list is not null?");
*PtrListEnd = &Entry;
PtrListEnd = Entry.setPrevInList(PtrListEnd);
assert(*PtrListEnd == 0 && "End of list is not null?");
addRef(); // Entry points to alias set.
}
/// 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;
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 AliasSet::addPointer(AliasSetTracker &AST, HashNodePair &Entry,
unsigned Size, bool KnownMustAlias) {
assert(!Entry.second.hasAliasSet() && "Entry already in set!");
// Check to see if we have to downgrade to _may_ alias.
if (isMustAlias() && !KnownMustAlias)
if (HashNodePair *P = getSomePointer()) {
AliasAnalysis &AA = AST.getAliasAnalysis();
AliasAnalysis::AliasResult Result =
AA.alias(P->first, P->second.getSize(), Entry.first, Size);
if (Result == AliasAnalysis::MayAlias)
AliasTy = MayAlias;
else // First entry of must alias must have maximum size!
P->second.updateSize(Size);
assert(Result != AliasAnalysis::NoAlias && "Cannot be part of must set!");
}
Entry.second.setAliasSet(this);
Entry.second.updateSize(Size);
// Add it to the end of the list...
assert(*PtrListEnd == 0 && "End of list is not null?");
*PtrListEnd = &Entry;
PtrListEnd = Entry.second.setPrevInList(PtrListEnd);
assert(*PtrListEnd == 0 && "End of list is not null?");
addRef(); // Entry points to alias set...
}
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_iterator I = AST.begin(), E = AST.end(); I != E; ++I)
if (!I->Forward) { // Ignore forwarding alias sets
AliasSet &AS = const_cast<AliasSet&>(*I);
// If there are any call sites in the alias set, add them to this AST.
for (unsigned i = 0, e = AS.CallSites.size(); i != e; ++i)
add(AS.CallSites[i]);
// Loop over all of the pointers in this alias set...
AliasSet::iterator I = AS.begin(), E = AS.end();
bool X;
for (; I != E; ++I)
addPointer(I.getPointer(), I.getSize(),
(AliasSet::AccessType)AS.AccessTy, X);
}
}
/// 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!!");
// Update the alias and access types of this set...
AccessTy |= AS.AccessTy;
AliasTy |= AS.AliasTy;
Volatile |= AS.Volatile;
if (AliasTy == MustAlias) {
// 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(AliasAnalysis::Location(L->getValue(),
L->getSize(),
L->getTBAAInfo()),
AliasAnalysis::Location(R->getValue(),
R->getSize(),
R->getTBAAInfo()))
!= AliasAnalysis::MustAlias)
AliasTy = MayAlias;
}
if (CallSites.empty()) { // Merge call sites...
if (!AS.CallSites.empty())
std::swap(CallSites, AS.CallSites);
} else if (!AS.CallSites.empty()) {
CallSites.insert(CallSites.end(), AS.CallSites.begin(), AS.CallSites.end());
AS.CallSites.clear();
}
AS.Forward = this; // Forward across AS now...
addRef(); // AS is now pointing to us...
// Merge the list of constituent pointers...
if (AS.PtrList) {
*PtrListEnd = AS.PtrList;
AS.PtrList->setPrevInList(PtrListEnd);
PtrListEnd = AS.PtrListEnd;
AS.PtrList = 0;
AS.PtrListEnd = &AS.PtrList;
assert(*AS.PtrListEnd == 0 && "End of list is not null?");
}
}
void AliasSet::addPointer(AliasSetTracker &AST, PointerRec &Entry,
LocationSize 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::removeFromTracker(AliasSetTracker &AST) {
assert(RefCount == 0 && "Cannot remove non-dead alias set from tracker!");
AST.removeAliasSet(this);
}
DeadMemOpElimination::instr_iterator
DeadMemOpElimination::handleMemOp(instr_iterator I, DefMapTy &Defs,
AliasSetTracker &AST) {
MachineInstr *MI = I;
MachineMemOperand *MO = *MI->memoperands_begin();
// AliasAnalysis cannot handle offset right now, so we pretend to write a
// a big enough size to the location pointed by the base pointer.
uint64_t Size = MO->getSize() + MO->getOffset();
AliasSet *ASet = &AST.getAliasSetForPointer(const_cast<Value*>(MO->getValue()),
Size, 0);
MachineInstr *&LastMI = Defs[ASet];
bool canHandleLastStore = LastMI && ASet->isMustAlias()
&& LastMI->getOpcode() != VTM::VOpInternalCall
// FIXME: We may need to remember the last
// definition for all predicates.
&& isPredIdentical(LastMI, MI);
if (canHandleLastStore) {
MachineMemOperand *LastMO = *LastMI->memoperands_begin();
// We can only handle last store if and only if their memory operand have
// the must-alias address and the same size.
canHandleLastStore = LastMO->getSize() == MO->getSize()
&& !LastMO->isVolatile()
&& MachineMemOperandAlias(MO, LastMO, AA, SE)
== AliasAnalysis::MustAlias;
}
// FIXME: These elimination is only valid if we are in single-thread mode!
if (VInstrInfo::mayStore(MI)) {
if (canHandleLastStore) {
// Dead store find, remove it.
LastMI->eraseFromParent();
++DeadStoreEliminated;
}
// Update the definition.
LastMI = MI;
return I;
}
// Now MI is a load.
if (!canHandleLastStore) return I;
// Loading the value that just be stored, the load is not necessary.
MachineOperand LoadedMO = MI->getOperand(0);
MachineOperand StoredMO = LastMI->getOperand(2);
// Simply replace the load by a copy.
DebugLoc dl = MI->getDebugLoc();
I = *BuildMI(*MI->getParent(), I, dl, VInstrInfo::getDesc(VTM::VOpMove))
.addOperand(LoadedMO).addOperand(StoredMO).
addOperand(*VInstrInfo::getPredOperand(MI)).
addOperand(*VInstrInfo::getTraceOperand(MI));
MI->eraseFromParent();
++DeadLoadEliminated;
return I;
}
