void SelectionDAGBuilder::visitGCRelocate(const GCRelocateInst &Relocate) {
#ifndef NDEBUG
// Consistency check
// We skip this check for relocates not in the same basic block as thier
// statepoint. It would be too expensive to preserve validation info through
// different basic blocks.
if (Relocate.getStatepoint()->getParent() == Relocate.getParent())
StatepointLowering.relocCallVisited(Relocate);
auto *Ty = Relocate.getType()->getScalarType();
if (auto IsManaged = GFI->getStrategy().isGCManagedPointer(Ty))
assert(*IsManaged && "Non gc managed pointer relocated!");
#endif
const Value *DerivedPtr = Relocate.getDerivedPtr();
SDValue SD = getValue(DerivedPtr);
auto &SpillMap = FuncInfo.StatepointSpillMaps[Relocate.getStatepoint()];
auto SlotIt = SpillMap.find(DerivedPtr);
assert(SlotIt != SpillMap.end() && "Relocating not lowered gc value");
Optional<int> DerivedPtrLocation = SlotIt->second;
// We didn't need to spill these special cases (constants and allocas).
// See the handling in spillIncomingValueForStatepoint for detail.
if (!DerivedPtrLocation) {
setValue(&Relocate, SD);
return;
}
SDValue SpillSlot = DAG.getTargetFrameIndex(*DerivedPtrLocation,
SD.getValueType());
// Be conservative: flush all pending loads
// TODO: Probably we can be less restrictive on this,
// it may allow more scheduling opportunities.
SDValue Chain = getRoot();
SDValue SpillLoad =
DAG.getLoad(SpillSlot.getValueType(), getCurSDLoc(), Chain, SpillSlot,
MachinePointerInfo::getFixedStack(DAG.getMachineFunction(),
*DerivedPtrLocation),
false, false, false, 0);
// Again, be conservative, don't emit pending loads
DAG.setRoot(SpillLoad.getValue(1));
assert(SpillLoad.getNode());
setValue(&Relocate, SpillLoad);
}
