SDValue
SparcTargetLowering::LowerReturn(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
DebugLoc dl, SelectionDAG &DAG) const {
MachineFunction &MF = DAG.getMachineFunction();
// CCValAssign - represent the assignment of the return value to locations.
SmallVector<CCValAssign, 16> RVLocs;
// CCState - Info about the registers and stack slot.
CCState CCInfo(CallConv, isVarArg, DAG.getTarget(),
RVLocs, *DAG.getContext());
// Analize return values.
CCInfo.AnalyzeReturn(Outs, RetCC_Sparc32);
// If this is the first return lowered for this function, add the regs to the
// liveout set for the function.
if (MF.getRegInfo().liveout_empty()) {
for (unsigned i = 0; i != RVLocs.size(); ++i)
if (RVLocs[i].isRegLoc())
MF.getRegInfo().addLiveOut(RVLocs[i].getLocReg());
}
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!");
Chain = DAG.getCopyToReg(Chain, dl, VA.getLocReg(),
OutVals[i], Flag);
// Guarantee that all emitted copies are stuck together with flags.
Flag = Chain.getValue(1);
}
unsigned RetAddrOffset = 8; //Call Inst + Delay Slot
// If the function returns a struct, copy the SRetReturnReg to I0
if (MF.getFunction()->hasStructRetAttr()) {
SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
unsigned Reg = SFI->getSRetReturnReg();
if (!Reg)
llvm_unreachable("sret virtual register not created in the entry block");
SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
Chain = DAG.getCopyToReg(Chain, dl, SP::I0, Val, Flag);
Flag = Chain.getValue(1);
if (MF.getRegInfo().liveout_empty())
MF.getRegInfo().addLiveOut(SP::I0);
RetAddrOffset = 12; // CallInst + Delay Slot + Unimp
}
SDValue RetAddrOffsetNode = DAG.getConstant(RetAddrOffset, MVT::i32);
if (Flag.getNode())
return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain,
RetAddrOffsetNode, Flag);
return DAG.getNode(SPISD::RET_FLAG, dl, MVT::Other, Chain,
RetAddrOffsetNode);
}
/// LowerFormalArguments - V8 uses a very simple ABI, where all values are
/// passed in either one or two GPRs, including FP values. TODO: we should
/// pass FP values in FP registers for fastcc functions.
SDValue
SparcTargetLowering::LowerFormalArguments(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg>
&Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals)
const {
MachineFunction &MF = DAG.getMachineFunction();
MachineRegisterInfo &RegInfo = MF.getRegInfo();
SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
// Assign locations to all of the incoming arguments.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
ArgLocs, *DAG.getContext());
CCInfo.AnalyzeFormalArguments(Ins, CC_Sparc32);
const unsigned StackOffset = 92;
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
if (i == 0 && Ins[i].Flags.isSRet()) {
//Get SRet from [%fp+64]
int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, 64, true);
SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
SDValue Arg = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
MachinePointerInfo(),
false, false, 0);
InVals.push_back(Arg);
continue;
}
if (VA.isRegLoc()) {
if (VA.needsCustom()) {
assert(VA.getLocVT() == MVT::f64);
unsigned VRegHi = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
MF.getRegInfo().addLiveIn(VA.getLocReg(), VRegHi);
SDValue HiVal = DAG.getCopyFromReg(Chain, dl, VRegHi, MVT::i32);
assert(i+1 < e);
CCValAssign &NextVA = ArgLocs[++i];
SDValue LoVal;
if (NextVA.isMemLoc()) {
int FrameIdx = MF.getFrameInfo()->
CreateFixedObject(4, StackOffset+NextVA.getLocMemOffset(),true);
SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
MachinePointerInfo(),
false, false, 0);
} else {
unsigned loReg = MF.addLiveIn(NextVA.getLocReg(),
&SP::IntRegsRegClass);
LoVal = DAG.getCopyFromReg(Chain, dl, loReg, MVT::i32);
}
SDValue WholeValue =
DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
InVals.push_back(WholeValue);
continue;
}
unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
MF.getRegInfo().addLiveIn(VA.getLocReg(), VReg);
SDValue Arg = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i32);
if (VA.getLocVT() == MVT::f32)
Arg = DAG.getNode(ISD::BITCAST, dl, MVT::f32, Arg);
else if (VA.getLocVT() != MVT::i32) {
Arg = DAG.getNode(ISD::AssertSext, dl, MVT::i32, Arg,
DAG.getValueType(VA.getLocVT()));
Arg = DAG.getNode(ISD::TRUNCATE, dl, VA.getLocVT(), Arg);
}
InVals.push_back(Arg);
continue;
}
assert(VA.isMemLoc());
unsigned Offset = VA.getLocMemOffset()+StackOffset;
if (VA.needsCustom()) {
assert(VA.getValVT() == MVT::f64);
//If it is double-word aligned, just load.
if (Offset % 8 == 0) {
int FI = MF.getFrameInfo()->CreateFixedObject(8,
Offset,
true);
SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
SDValue Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
MachinePointerInfo(),
false,false, 0);
InVals.push_back(Load);
continue;
}
int FI = MF.getFrameInfo()->CreateFixedObject(4,
Offset,
true);
SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
SDValue HiVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr,
MachinePointerInfo(),
false, false, 0);
int FI2 = MF.getFrameInfo()->CreateFixedObject(4,
Offset+4,
true);
SDValue FIPtr2 = DAG.getFrameIndex(FI2, getPointerTy());
SDValue LoVal = DAG.getLoad(MVT::i32, dl, Chain, FIPtr2,
MachinePointerInfo(),
false, false, 0);
SDValue WholeValue =
DAG.getNode(ISD::BUILD_PAIR, dl, MVT::i64, LoVal, HiVal);
WholeValue = DAG.getNode(ISD::BITCAST, dl, MVT::f64, WholeValue);
InVals.push_back(WholeValue);
continue;
}
int FI = MF.getFrameInfo()->CreateFixedObject(4,
Offset,
true);
SDValue FIPtr = DAG.getFrameIndex(FI, getPointerTy());
SDValue Load ;
if (VA.getValVT() == MVT::i32 || VA.getValVT() == MVT::f32) {
Load = DAG.getLoad(VA.getValVT(), dl, Chain, FIPtr,
MachinePointerInfo(),
false, false, 0);
} else {
ISD::LoadExtType LoadOp = ISD::SEXTLOAD;
// Sparc is big endian, so add an offset based on the ObjectVT.
unsigned Offset = 4-std::max(1U, VA.getValVT().getSizeInBits()/8);
FIPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, FIPtr,
DAG.getConstant(Offset, MVT::i32));
Load = DAG.getExtLoad(LoadOp, dl, MVT::i32, Chain, FIPtr,
MachinePointerInfo(),
VA.getValVT(), false, false,0);
Load = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), Load);
}
InVals.push_back(Load);
}
if (MF.getFunction()->hasStructRetAttr()) {
//Copy the SRet Argument to SRetReturnReg
SparcMachineFunctionInfo *SFI = MF.getInfo<SparcMachineFunctionInfo>();
unsigned Reg = SFI->getSRetReturnReg();
if (!Reg) {
Reg = MF.getRegInfo().createVirtualRegister(&SP::IntRegsRegClass);
SFI->setSRetReturnReg(Reg);
}
SDValue Copy = DAG.getCopyToReg(DAG.getEntryNode(), dl, Reg, InVals[0]);
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Copy, Chain);
}
// Store remaining ArgRegs to the stack if this is a varargs function.
if (isVarArg) {
static const unsigned ArgRegs[] = {
SP::I0, SP::I1, SP::I2, SP::I3, SP::I4, SP::I5
};
unsigned NumAllocated = CCInfo.getFirstUnallocated(ArgRegs, 6);
const unsigned *CurArgReg = ArgRegs+NumAllocated, *ArgRegEnd = ArgRegs+6;
unsigned ArgOffset = CCInfo.getNextStackOffset();
if (NumAllocated == 6)
ArgOffset += StackOffset;
else {
assert(!ArgOffset);
ArgOffset = 68+4*NumAllocated;
}
// Remember the vararg offset for the va_start implementation.
FuncInfo->setVarArgsFrameOffset(ArgOffset);
std::vector<SDValue> OutChains;
for (; CurArgReg != ArgRegEnd; ++CurArgReg) {
unsigned VReg = RegInfo.createVirtualRegister(&SP::IntRegsRegClass);
MF.getRegInfo().addLiveIn(*CurArgReg, VReg);
SDValue Arg = DAG.getCopyFromReg(DAG.getRoot(), dl, VReg, MVT::i32);
int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, ArgOffset,
true);
SDValue FIPtr = DAG.getFrameIndex(FrameIdx, MVT::i32);
OutChains.push_back(DAG.getStore(DAG.getRoot(), dl, Arg, FIPtr,
MachinePointerInfo(),
false, false, 0));
ArgOffset += 4;
}
if (!OutChains.empty()) {
OutChains.push_back(Chain);
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&OutChains[0], OutChains.size());
}
}
return Chain;
}