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[Attributor][NFC] Simplify common pattern wrt. fixpoints
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When a fixpoint is indicated the change status is known due to the
fixpoint kind. This simplifies a common code pattern by making the
connection explicit.

llvm-svn: 367790
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Johannes Doerfert committed Aug 4, 2019
1 parent b6acee5 commit d1c3793
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Showing 2 changed files with 55 additions and 74 deletions.
18 changes: 14 additions & 4 deletions llvm/include/llvm/Transforms/IPO/Attributor.h
View file
Expand Up @@ -375,13 +375,17 @@ struct AbstractState {
///
/// This will usually make the optimistically assumed state the known to be
/// true state.
virtual void indicateOptimisticFixpoint() = 0;
///
/// \returns ChangeStatus::UNCHANGED as the assumed value should not change.
virtual ChangeStatus indicateOptimisticFixpoint() = 0;

/// Indicate that the abstract state should converge to the pessimistic state.
///
/// This will usually revert the optimistically assumed state to the known to
/// be true state.
virtual void indicatePessimisticFixpoint() = 0;
///
/// \returns ChangeStatus::CHANGED as the assumed value may change.
virtual ChangeStatus indicatePessimisticFixpoint() = 0;
};

/// Simple state with integers encoding.
Expand Down Expand Up @@ -412,10 +416,16 @@ struct IntegerState : public AbstractState {
bool isAtFixpoint() const override { return Assumed == Known; }

/// See AbstractState::indicateOptimisticFixpoint(...)
void indicateOptimisticFixpoint() override { Known = Assumed; }
ChangeStatus indicateOptimisticFixpoint() override {
Known = Assumed;
return ChangeStatus::UNCHANGED;
}

/// See AbstractState::indicatePessimisticFixpoint(...)
void indicatePessimisticFixpoint() override { Assumed = Known; }
ChangeStatus indicatePessimisticFixpoint() override {
Assumed = Known;
return ChangeStatus::CHANGED;
}

/// Return the known state encoding
base_t getKnown() const { return Known; }
Expand Down
111 changes: 41 additions & 70 deletions llvm/lib/Transforms/IPO/Attributor.cpp
View file
Expand Up @@ -488,10 +488,8 @@ ChangeStatus AANoUnwindFunction::updateImpl(Attributor &A) {

auto *NoUnwindAA = A.getAAFor<AANoUnwind>(*this, *I);

if (!NoUnwindAA || !NoUnwindAA->isAssumedNoUnwind()) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!NoUnwindAA || !NoUnwindAA->isAssumedNoUnwind())
return indicatePessimisticFixpoint();
}
}
return ChangeStatus::UNCHANGED;
Expand Down Expand Up @@ -625,14 +623,16 @@ class AAReturnedValuesImpl final : public AAReturnedValues, AbstractState {
bool isValidState() const override { return IsValidState; }

/// See AbstractState::indicateOptimisticFixpoint(...).
void indicateOptimisticFixpoint() override {
ChangeStatus indicateOptimisticFixpoint() override {
IsFixed = true;
IsValidState &= true;
return ChangeStatus::UNCHANGED;
}

void indicatePessimisticFixpoint() override {
ChangeStatus indicatePessimisticFixpoint() override {
IsFixed = true;
IsValidState = false;
return ChangeStatus::CHANGED;
}
};

Expand Down Expand Up @@ -1000,19 +1000,16 @@ ChangeStatus AANoSyncFunction::updateImpl(Attributor &A) {
continue;

if (ICS && (!NoSyncAA || !NoSyncAA->isAssumedNoSync()) &&
!ICS.hasFnAttr(Attribute::NoSync)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
!ICS.hasFnAttr(Attribute::NoSync))
return indicatePessimisticFixpoint();

if (ICS)
continue;

if (!isVolatile(I) && !isNonRelaxedAtomic(I))
continue;

indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
return indicatePessimisticFixpoint();
}

auto &OpcodeInstMap = InfoCache.getOpcodeInstMapForFunction(F);
Expand All @@ -1035,8 +1032,7 @@ ChangeStatus AANoSyncFunction::updateImpl(Attributor &A) {
if (!ICS.isConvergent())
continue;

indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
return indicatePessimisticFixpoint();
}
}

Expand Down Expand Up @@ -1100,10 +1096,8 @@ ChangeStatus AANoFreeFunction::updateImpl(Attributor &A) {
auto *NoFreeAA = A.getAAFor<AANoFreeFunction>(*this, *I);

if ((!NoFreeAA || !NoFreeAA->isAssumedNoFree()) &&
!ICS.hasFnAttr(Attribute::NoFree)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
!ICS.hasFnAttr(Attribute::NoFree))
return indicatePessimisticFixpoint();
}
}
return ChangeStatus::UNCHANGED;
Expand Down Expand Up @@ -1203,18 +1197,14 @@ ChangeStatus AANonNullReturned::updateImpl(Attributor &A) {
Function &F = getAnchorScope();

auto *AARetVal = A.getAAFor<AAReturnedValues>(*this, F);
if (!AARetVal) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetVal)
return indicatePessimisticFixpoint();

std::function<bool(Value &, const SmallPtrSetImpl<ReturnInst *> &)> Pred =
this->generatePredicate(A);

if (!AARetVal->checkForallReturnedValues(Pred)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetVal->checkForallReturnedValues(Pred))
return indicatePessimisticFixpoint();
return ChangeStatus::UNCHANGED;
}

Expand Down Expand Up @@ -1300,10 +1290,8 @@ ChangeStatus AANonNullArgument::updateImpl(Attributor &A) {

return false;
};
if (!A.checkForAllCallSites(F, CallSiteCheck, true, *this)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!A.checkForAllCallSites(F, CallSiteCheck, true, *this))
return indicatePessimisticFixpoint();
return ChangeStatus::UNCHANGED;
}

Expand All @@ -1315,10 +1303,8 @@ ChangeStatus AANonNullCallSiteArgument::updateImpl(Attributor &A) {

auto *NonNullAA = A.getAAFor<AANonNull>(*this, V);

if (!NonNullAA || !NonNullAA->isAssumedNonNull()) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!NonNullAA || !NonNullAA->isAssumedNonNull())
return indicatePessimisticFixpoint();

return ChangeStatus::UNCHANGED;
}
Expand Down Expand Up @@ -1416,10 +1402,8 @@ ChangeStatus AAWillReturnFunction::updateImpl(Attributor &A) {
continue;

auto *WillReturnAA = A.getAAFor<AAWillReturn>(*this, *I);
if (!WillReturnAA || !WillReturnAA->isAssumedWillReturn()) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!WillReturnAA || !WillReturnAA->isAssumedWillReturn())
return indicatePessimisticFixpoint();

auto *NoRecurseAA = A.getAAFor<AANoRecurse>(*this, *I);

Expand All @@ -1428,10 +1412,8 @@ ChangeStatus AAWillReturnFunction::updateImpl(Attributor &A) {
// regarded as having recursion.
// Code below should be
// if ((!NoRecurseAA || !NoRecurseAA->isAssumedNoRecurse()) &&
if (!NoRecurseAA && !ICS.hasFnAttr(Attribute::NoRecurse)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!NoRecurseAA && !ICS.hasFnAttr(Attribute::NoRecurse))
return indicatePessimisticFixpoint();
}
}

Expand Down Expand Up @@ -1492,10 +1474,8 @@ ChangeStatus AANoAliasReturned::updateImpl(Attributor &A) {
Function &F = getAnchorScope();

auto *AARetValImpl = A.getAAFor<AAReturnedValuesImpl>(*this, F);
if (!AARetValImpl) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetValImpl)
return indicatePessimisticFixpoint();

std::function<bool(Value &, const SmallPtrSetImpl<ReturnInst *> &)> Pred =
[&](Value &RV, const SmallPtrSetImpl<ReturnInst *> &RetInsts) -> bool {
Expand Down Expand Up @@ -1525,10 +1505,8 @@ ChangeStatus AANoAliasReturned::updateImpl(Attributor &A) {
return true;
};

if (!AARetValImpl->checkForallReturnedValues(Pred)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetValImpl->checkForallReturnedValues(Pred))
return indicatePessimisticFixpoint();

return ChangeStatus::UNCHANGED;
}
Expand Down Expand Up @@ -1764,15 +1742,17 @@ struct DerefState : AbstractState {
}

/// See AbstractState::indicateOptimisticFixpoint(...)
void indicateOptimisticFixpoint() override {
ChangeStatus indicateOptimisticFixpoint() override {
DerefBytesState.indicateOptimisticFixpoint();
NonNullGlobalState.indicateOptimisticFixpoint();
return ChangeStatus::UNCHANGED;
}

/// See AbstractState::indicatePessimisticFixpoint(...)
void indicatePessimisticFixpoint() override {
ChangeStatus indicatePessimisticFixpoint() override {
DerefBytesState.indicatePessimisticFixpoint();
NonNullGlobalState.indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}

/// Update known dereferenceable bytes.
Expand Down Expand Up @@ -1958,10 +1938,8 @@ ChangeStatus AADereferenceableReturned::updateImpl(Attributor &A) {
syncNonNull(A.getAAFor<AANonNull>(*this, F));

auto *AARetVal = A.getAAFor<AAReturnedValues>(*this, F);
if (!AARetVal) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetVal)
return indicatePessimisticFixpoint();

bool IsNonNull = isAssumedNonNull();
bool IsGlobal = isAssumedGlobal();
Expand All @@ -1979,8 +1957,7 @@ ChangeStatus AADereferenceableReturned::updateImpl(Attributor &A) {
? ChangeStatus::UNCHANGED
: ChangeStatus::CHANGED;
}
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
return indicatePessimisticFixpoint();
}

struct AADereferenceableArgument : AADereferenceableImpl {
Expand Down Expand Up @@ -2030,10 +2007,8 @@ ChangeStatus AADereferenceableArgument::updateImpl(Attributor &A) {
return isValidState();
};

if (!A.checkForAllCallSites(F, CallSiteCheck, true, *this)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!A.checkForAllCallSites(F, CallSiteCheck, true, *this))
return indicatePessimisticFixpoint();

updateAssumedNonNullGlobalState(IsNonNull, IsGlobal);

Expand Down Expand Up @@ -2171,10 +2146,8 @@ struct AAAlignReturned : AAAlignImpl {
ChangeStatus AAAlignReturned::updateImpl(Attributor &A) {
Function &F = getAnchorScope();
auto *AARetValImpl = A.getAAFor<AAReturnedValuesImpl>(*this, F);
if (!AARetValImpl) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetValImpl)
return indicatePessimisticFixpoint();

// Currently, align<n> is deduced if alignments in return values are assumed
// as greater than n. We reach pessimistic fixpoint if any of the return value
Expand All @@ -2196,10 +2169,8 @@ ChangeStatus AAAlignReturned::updateImpl(Attributor &A) {
return isValidState();
};

if (!AARetValImpl->checkForallReturnedValues(Pred)) {
indicatePessimisticFixpoint();
return ChangeStatus::CHANGED;
}
if (!AARetValImpl->checkForallReturnedValues(Pred))
return indicatePessimisticFixpoint();

return (getAssumed() != BeforeState) ? ChangeStatus::CHANGED
: ChangeStatus::UNCHANGED;
Expand Down

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