bool
LSLocation::reduce(LSLocation Base, SILModule *M, LSLocationSet &Locs) {
// If this is a class reference type, we have reached end of the type tree.
if (Base.getType(M).getClassOrBoundGenericClass())
return Locs.find(Base) != Locs.end();
// This is a leaf node.
LSLocationList NextLevel;
Base.getNextLevelLSLocations(NextLevel, M);
if (NextLevel.empty())
return Locs.find(Base) != Locs.end();
// This is not a leaf node, try to find whether all its children are alive.
bool Alive = true;
for (auto &X : NextLevel) {
Alive &= LSLocation::reduce(X, M, Locs);
}
// All next level locations are alive, create the new aggregated location.
if (Alive) {
for (auto &X : NextLevel)
Locs.erase(X);
Locs.insert(Base);
}
return Alive;
}
void
LSValue::reduceInner(LSLocation &Base, SILModule *M, LSLocationValueMap &Values,
SILInstruction *InsertPt) {
// If this is a class reference type, we have reached end of the type tree.
if (Base.getType(M).getClassOrBoundGenericClass())
return;
// This is a leaf node, we must have a value for it.
LSLocationList NextLevel;
Base.getNextLevelLSLocations(NextLevel, M);
if (NextLevel.empty())
return;
// This is not a leaf node, reduce the next level node one by one.
for (auto &X : NextLevel) {
LSValue::reduceInner(X, M, Values, InsertPt);
}
// This is NOT a leaf node, we need to construct a value for it.
auto Iter = NextLevel.begin();
LSValue &FirstVal = Values[*Iter];
// There is only 1 children node and its value's projection path is not
// empty, keep stripping it.
if (NextLevel.size() == 1 && !FirstVal.hasEmptyProjectionPath()) {
Values[Base] = FirstVal.stripLastLevelProjection();
// We have a value for the parent, remove all the values for children.
removeLSLocations(Values, NextLevel);
return;
}
bool HasIdenticalBase = true;
SILValue FirstBase = FirstVal.getBase();
for (auto &X : NextLevel) {
HasIdenticalBase &= (FirstBase == Values[X].getBase());
}
// This is NOT a leaf node and it has multiple children, but they have the
// same value base.
if (NextLevel.size() > 1 && HasIdenticalBase) {
if (!FirstVal.hasEmptyProjectionPath()) {
Values[Base] = FirstVal.stripLastLevelProjection();
// We have a value for the parent, remove all the values for children.
removeLSLocations(Values, NextLevel);
return;
}
}
// In 3 cases do we need aggregation.
//
// 1. If there is only 1 child and we cannot strip off any projections,
// that means we need to create an aggregation.
//
// 2. There are multiple children and they have the same base, but empty
// projection paths.
//
// 3. Children have values from different bases, We need to create
// extractions and aggregation in this case.
//
llvm::SmallVector<SILValue, 8> Vals;
for (auto &X : NextLevel) {
Vals.push_back(Values[X].materialize(InsertPt));
}
SILBuilder Builder(InsertPt);
Builder.setCurrentDebugScope(InsertPt->getFunction()->getDebugScope());
// We use an auto-generated SILLocation for now.
NullablePtr<swift::SILInstruction> AI =
Projection::createAggFromFirstLevelProjections(
Builder, RegularLocation::getAutoGeneratedLocation(),
Base.getType(M).getObjectType(),
Vals);
// This is the Value for the current base.
ProjectionPath P(Base.getType(M));
Values[Base] = LSValue(SILValue(AI.get()), P);
removeLSLocations(Values, NextLevel);
}
