SDValue PTXTargetLowering::
LowerReturn(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl,
SelectionDAG &DAG) const {
if (isVarArg) llvm_unreachable("PTX does not support varargs");
switch (CallConv) {
default:
llvm_unreachable("Unsupported calling convention.");
case CallingConv::PTX_Kernel:
assert(Outs.size() == 0 && "Kernel must return void.");
return DAG.getNode(PTXISD::EXIT, dl, MVT::Other, Chain);
case CallingConv::PTX_Device:
//assert(Outs.size() <= 1 && "Can at most return one value.");
break;
}
MachineFunction& MF = DAG.getMachineFunction();
PTXMachineFunctionInfo *MFI = MF.getInfo<PTXMachineFunctionInfo>();
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
getTargetMachine(), RVLocs, *DAG.getContext());
SDValue Flag;
CCInfo.AnalyzeReturn(Outs, RetCC_PTX);
for (unsigned i = 0, e = RVLocs.size(); i != e; ++i) {
CCValAssign& VA = RVLocs[i];
assert(VA.isRegLoc() && "CCValAssign must be RegLoc");
unsigned Reg = VA.getLocReg();
DAG.getMachineFunction().getRegInfo().addLiveOut(Reg);
Chain = DAG.getCopyToReg(Chain, dl, Reg, OutVals[i], Flag);
// Guarantee that all emitted copies are stuck together,
// avoiding something bad
Flag = Chain.getValue(1);
MFI->addRetReg(Reg);
}
if (Flag.getNode() == 0) {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain);
}
else {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain, Flag);
}
}
SDValue PTXTargetLowering::
LowerReturn(SDValue Chain,
CallingConv::ID CallConv,
bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl,
SelectionDAG &DAG) const {
if (isVarArg) llvm_unreachable("PTX does not support varargs");
switch (CallConv) {
default:
llvm_unreachable("Unsupported calling convention.");
case CallingConv::PTX_Kernel:
assert(Outs.size() == 0 && "Kernel must return void.");
return DAG.getNode(PTXISD::EXIT, dl, MVT::Other, Chain);
case CallingConv::PTX_Device:
assert(Outs.size() <= 1 && "Can at most return one value.");
break;
}
MachineFunction& MF = DAG.getMachineFunction();
PTXMachineFunctionInfo *MFI = MF.getInfo<PTXMachineFunctionInfo>();
PTXParamManager &PM = MFI->getParamManager();
SDValue Flag;
const PTXSubtarget& ST = getTargetMachine().getSubtarget<PTXSubtarget>();
if (ST.useParamSpaceForDeviceArgs()) {
assert(Outs.size() < 2 && "Device functions can return at most one value");
if (Outs.size() == 1) {
unsigned ParamSize = OutVals[0].getValueType().getSizeInBits();
unsigned Param = PM.addReturnParam(ParamSize);
const std::string &ParamName = PM.getParamName(Param);
SDValue ParamValue = DAG.getTargetExternalSymbol(ParamName.c_str(),
MVT::Other);
Chain = DAG.getNode(PTXISD::STORE_PARAM, dl, MVT::Other, Chain,
ParamValue, OutVals[0]);
}
} else {
for (unsigned i = 0, e = Outs.size(); i != e; ++i) {
EVT RegVT = Outs[i].VT;
TargetRegisterClass* TRC = 0;
// Determine which register class we need
if (RegVT == MVT::i1) {
TRC = PTX::RegPredRegisterClass;
}
else if (RegVT == MVT::i16) {
TRC = PTX::RegI16RegisterClass;
}
else if (RegVT == MVT::i32) {
TRC = PTX::RegI32RegisterClass;
}
else if (RegVT == MVT::i64) {
TRC = PTX::RegI64RegisterClass;
}
else if (RegVT == MVT::f32) {
TRC = PTX::RegF32RegisterClass;
}
else if (RegVT == MVT::f64) {
TRC = PTX::RegF64RegisterClass;
}
else {
llvm_unreachable("Unknown parameter type");
}
unsigned Reg = MF.getRegInfo().createVirtualRegister(TRC);
SDValue Copy = DAG.getCopyToReg(Chain, dl, Reg, OutVals[i]/*, Flag*/);
SDValue OutReg = DAG.getRegister(Reg, RegVT);
Chain = DAG.getNode(PTXISD::WRITE_PARAM, dl, MVT::Other, Copy, OutReg);
MFI->addRetReg(Reg);
}
}
if (Flag.getNode() == 0) {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain);
}
else {
return DAG.getNode(PTXISD::RET, dl, MVT::Other, Chain, Flag);
}
}