setStackPointerRegisterToSaveRestore(SystemZ::R15);
setSchedulingPreference(SchedulingForLatency);
+
+ setOperationAction(ISD::RET, MVT::Other, Custom);
+
}
SDValue SystemZTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
+ case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
+ case ISD::RET: return LowerRET(Op, DAG);
default:
assert(0 && "unimplemented operand");
return SDValue();
#include "SystemZGenCallingConv.inc"
+SDValue SystemZTargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op,
+ SelectionDAG &DAG) {
+ unsigned CC = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
+ switch (CC) {
+ default:
+ assert(0 && "Unsupported calling convention");
+ case CallingConv::C:
+ case CallingConv::Fast:
+ return LowerCCCArguments(Op, DAG);
+ }
+}
+
+/// LowerCCCArguments - transform physical registers into virtual registers and
+/// generate load operations for arguments places on the stack.
+// FIXME: struct return stuff
+// FIXME: varargs
+SDValue SystemZTargetLowering::LowerCCCArguments(SDValue Op,
+ SelectionDAG &DAG) {
+ MachineFunction &MF = DAG.getMachineFunction();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MachineRegisterInfo &RegInfo = MF.getRegInfo();
+ SDValue Root = Op.getOperand(0);
+ bool isVarArg = cast<ConstantSDNode>(Op.getOperand(2))->getZExtValue() != 0;
+ unsigned CC = MF.getFunction()->getCallingConv();
+ DebugLoc dl = Op.getDebugLoc();
+
+ // Assign locations to all of the incoming arguments.
+ SmallVector<CCValAssign, 16> ArgLocs;
+ CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs);
+ CCInfo.AnalyzeFormalArguments(Op.getNode(), CC_SystemZ);
+
+ assert(!isVarArg && "Varargs not supported yet");
+
+ SmallVector<SDValue, 16> ArgValues;
+ for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
+ CCValAssign &VA = ArgLocs[i];
+ if (VA.isRegLoc()) {
+ // Arguments passed in registers
+ MVT RegVT = VA.getLocVT();
+ switch (RegVT.getSimpleVT()) {
+ default:
+ cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
+ << RegVT.getSimpleVT()
+ << "\n";
+ abort();
+ case MVT::i64:
+ unsigned VReg =
+ RegInfo.createVirtualRegister(SystemZ::GR64RegisterClass);
+ RegInfo.addLiveIn(VA.getLocReg(), VReg);
+ SDValue ArgValue = DAG.getCopyFromReg(Root, dl, VReg, RegVT);
+
+ // If this is an 8/16/32-bit value, it is really passed promoted to 64
+ // bits. Insert an assert[sz]ext to capture this, then truncate to the
+ // right size.
+ if (VA.getLocInfo() == CCValAssign::SExt)
+ ArgValue = DAG.getNode(ISD::AssertSext, dl, RegVT, ArgValue,
+ DAG.getValueType(VA.getValVT()));
+ else if (VA.getLocInfo() == CCValAssign::ZExt)
+ ArgValue = DAG.getNode(ISD::AssertZext, dl, RegVT, ArgValue,
+ DAG.getValueType(VA.getValVT()));
+
+ if (VA.getLocInfo() != CCValAssign::Full)
+ ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
+
+ ArgValues.push_back(ArgValue);
+ }
+ } else {
+ // Sanity check
+ assert(VA.isMemLoc());
+ // Load the argument to a virtual register
+ unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
+ if (ObjSize > 8) {
+ cerr << "LowerFORMAL_ARGUMENTS Unhandled argument type: "
+ << VA.getLocVT().getSimpleVT()
+ << "\n";
+ }
+ // Create the frame index object for this incoming parameter...
+ int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset());
+
+ // Create the SelectionDAG nodes corresponding to a load
+ //from this parameter
+ SDValue FIN = DAG.getFrameIndex(FI, MVT::i64);
+ ArgValues.push_back(DAG.getLoad(VA.getLocVT(), dl, Root, FIN,
+ PseudoSourceValue::getFixedStack(FI), 0));
+ }
+ }
+
+ ArgValues.push_back(Root);
+
+ // Return the new list of results.
+ return DAG.getNode(ISD::MERGE_VALUES, dl, Op.getNode()->getVTList(),
+ &ArgValues[0], ArgValues.size()).getValue(Op.getResNo());
+}
+
+SDValue SystemZTargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
+ // CCValAssign - represent the assignment of the return value to a location
+ SmallVector<CCValAssign, 16> RVLocs;
+ unsigned CC = DAG.getMachineFunction().getFunction()->getCallingConv();
+ bool isVarArg = DAG.getMachineFunction().getFunction()->isVarArg();
+ DebugLoc dl = Op.getDebugLoc();
+
+ // CCState - Info about the registers and stack slot.
+ CCState CCInfo(CC, isVarArg, getTargetMachine(), RVLocs);
+
+ // Analize return values of ISD::RET
+ CCInfo.AnalyzeReturn(Op.getNode(), RetCC_SystemZ);
+
+ // If this is the first return lowered for this function, add the regs to the
+ // liveout set for the function.
+ if (DAG.getMachineFunction().getRegInfo().liveout_empty()) {
+ for (unsigned i = 0; i != RVLocs.size(); ++i)
+ if (RVLocs[i].isRegLoc())
+ DAG.getMachineFunction().getRegInfo().addLiveOut(RVLocs[i].getLocReg());
+ }
+
+ // The chain is always operand #0
+ SDValue Chain = Op.getOperand(0);
+ SDValue Flag;
+
+ // Copy the result values into the output registers.
+ for (unsigned i = 0; i != RVLocs.size(); ++i) {
+ CCValAssign &VA = RVLocs[i];
+ assert(VA.isRegLoc() && "Can only return in registers!");
+
+ // ISD::RET => ret chain, (regnum1,val1), ...
+ // So i*2+1 index only the regnums
+ Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
+ Op.getOperand(i*2+1), Flag);
+
+ // Guarantee that all emitted copies are stuck together,
+ // avoiding something bad.
+ Flag = Chain.getValue(1);
+ }
+
+ if (Flag.getNode())
+ return DAG.getNode(SystemZISD::RET_FLAG, dl, MVT::Other, Chain, Flag);
+
+ // Return Void
+ return DAG.getNode(SystemZISD::RET_FLAG, dl, MVT::Other, Chain);
+}
+
const char *SystemZTargetLowering::getTargetNodeName(unsigned Opcode) const {
switch (Opcode) {
+ case SystemZISD::RET_FLAG: return "SystemZISD::RET_FLAG";
default: return NULL;
}
}