void BlockState::mergePredecessorAvailSetAndValue(RLEContext &Ctx) {
// Clear the state if the basic block has no predecessor.
if (BB->getPreds().begin() == BB->getPreds().end()) {
ForwardSetIn.reset();
ForwardValIn.clear();
return;
}
auto Iter = BB->pred_begin();
ForwardSetIn = Ctx.getBlockState(*Iter).ForwardSetOut;
ForwardValIn = Ctx.getBlockState(*Iter).ForwardValOut;
Iter = std::next(Iter);
for (auto EndIter = BB->pred_end(); Iter != EndIter; ++Iter) {
BlockState &OtherState = Ctx.getBlockState(*Iter);
ForwardSetIn &= OtherState.ForwardSetOut;
// Merge in the predecessor state.
for (unsigned i = 0; i < LocationNum; ++i) {
if (OtherState.ForwardSetOut[i]) {
// There are multiple values from multiple predecessors, set this as
// a covering value. We do not need to track the value itself, as we
// can always go to the predecessors BlockState to find it.
ForwardValIn[i] = Ctx.getValueBit(LSValue(true));
continue;
}
// If this location does have an available value, then clear it.
stopTrackingValue(ForwardValIn, i);
stopTrackingLocation(ForwardSetIn, i);
}
}
}
void BlockState::mergePredecessorsAvailSetMax(RLEContext &Ctx) {
if (BB->pred_empty()) {
ForwardSetMax.reset();
return;
}
auto Iter = BB->pred_begin();
ForwardSetMax = Ctx.getBlockState(*Iter).ForwardSetMax;
Iter = std::next(Iter);
for (auto EndIter = BB->pred_end(); Iter != EndIter; ++Iter) {
ForwardSetMax &= Ctx.getBlockState(*Iter).ForwardSetMax;
}
}
void BlockState::mergePredecessorAvailSet(RLEContext &Ctx) {
// Clear the state if the basic block has no predecessor.
if (BB->getPreds().begin() == BB->getPreds().end()) {
ForwardSetIn.reset();
return;
}
auto Iter = BB->pred_begin();
ForwardSetIn = Ctx.getBlockState(*Iter).ForwardSetOut;
Iter = std::next(Iter);
for (auto EndIter = BB->pred_end(); Iter != EndIter; ++Iter) {
ForwardSetIn &= Ctx.getBlockState(*Iter).ForwardSetOut;
}
}
void BlockState::mergePredecessorStates(RLEContext &Ctx, RLEKind Kind) {
// Clear the state if the basic block has no predecessor.
if (BB->getPreds().begin() == BB->getPreds().end()) {
clearLSLocations();
return;
}
// We initialize the state with the first predecessor's state and merge
// in states of other predecessors.
bool HasAtLeastOnePred = false;
// For each predecessor of BB...
for (auto Pred : BB->getPreds()) {
BlockState &Other = Ctx.getBlockState(Pred);
// If we have not had at least one predecessor, initialize BlockState
// with the state of the initial predecessor.
// If BB is also a predecessor of itself, we should not initialize.
if (!HasAtLeastOnePred) {
if (isComputeAvailSet(Kind)) {
ForwardSetIn = Other.ForwardSetOut;
}
if (isComputeAvailValue(Kind) || isPerformRLE(Kind)) {
ForwardSetIn = Other.ForwardSetOut;
ForwardValIn = Other.ForwardValOut;
}
} else {
mergePredecessorState(Ctx, Other, Kind);
}
HasAtLeastOnePred = true;
}
}