SDValue WebAssemblyTargetLowering::LowerBR_JT(SDValue Op,
SelectionDAG &DAG) const {
SDLoc DL(Op);
SDValue Chain = Op.getOperand(0);
const auto *JT = cast<JumpTableSDNode>(Op.getOperand(1));
SDValue Index = Op.getOperand(2);
assert(JT->getTargetFlags() == 0 && "WebAssembly doesn't set target flags");
SmallVector<SDValue, 8> Ops;
Ops.push_back(Chain);
Ops.push_back(Index);
MachineJumpTableInfo *MJTI = DAG.getMachineFunction().getJumpTableInfo();
const auto &MBBs = MJTI->getJumpTables()[JT->getIndex()].MBBs;
// TODO: For now, we just pick something arbitrary for a default case for now.
// We really want to sniff out the guard and put in the real default case (and
// delete the guard).
Ops.push_back(DAG.getBasicBlock(MBBs[0]));
// Add an operand for each case.
for (auto MBB : MBBs)
Ops.push_back(DAG.getBasicBlock(MBB));
return DAG.getNode(WebAssemblyISD::SWITCH, DL, MVT::Other, Ops);
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineJumpTable &YamlJTI,
const MachineJumpTableInfo &JTI) {
YamlJTI.Kind = JTI.getEntryKind();
unsigned ID = 0;
for (const auto &Table : JTI.getJumpTables()) {
std::string Str;
yaml::MachineJumpTable::Entry Entry;
Entry.ID = ID++;
for (const auto *MBB : Table.MBBs) {
raw_string_ostream StrOS(Str);
StrOS << printMBBReference(*MBB);
Entry.Blocks.push_back(StrOS.str());
Str.clear();
}
YamlJTI.Entries.push_back(Entry);
}
}