static void UpdateNodeOperand(SelectionDAG &DAG, SDNode *N, unsigned Num,
SDValue Val) {
SmallVector<SDValue, 8> ops(N->op_begin(), N->op_end());
ops[Num] = Val;
SDNode *New = DAG.UpdateNodeOperands(N, ops.data(), ops.size());
DAG.ReplaceAllUsesWith(N, New);
}
SDValue
Cpu0TargetLowering::LowerCall(SDValue InChain, SDValue Callee,
CallingConv::ID CallConv, bool isVarArg,
bool doesNotRet, bool &isTailCall,
const SmallVectorImpl<ISD::OutputArg> &Outs,
const SmallVectorImpl<SDValue> &OutVals,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals) const {
#if 1
// Cpu0 target does not yet support tail call optimization.
isTailCall = false;
MachineFunction &MF = DAG.getMachineFunction();
MachineFrameInfo *MFI = MF.getFrameInfo();
const TargetFrameLowering *TFL = MF.getTarget().getFrameLowering();
bool IsPIC = getTargetMachine().getRelocationModel() == Reloc::PIC_;
Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>();
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CallConv, isVarArg, DAG.getMachineFunction(),
getTargetMachine(), ArgLocs, *DAG.getContext());
CCInfo.AnalyzeCallOperands(Outs, CC_Cpu0);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NextStackOffset = CCInfo.getNextStackOffset();
// Chain is the output chain of the last Load/Store or CopyToReg node.
// ByValChain is the output chain of the last Memcpy node created for copying
// byval arguments to the stack.
SDValue Chain, CallSeqStart, ByValChain;
SDValue NextStackOffsetVal = DAG.getIntPtrConstant(NextStackOffset, true);
Chain = CallSeqStart = DAG.getCALLSEQ_START(InChain, NextStackOffsetVal);
ByValChain = InChain;
#if 0
// If this is the first call, create a stack frame object that points to
// a location to which .cprestore saves $gp.
if (IsO32 && IsPIC && Cpu0FI->globalBaseRegFixed() && !Cpu0FI->getGPFI())
Cpu0FI->setGPFI(MFI->CreateFixedObject(4, 0, true));
#endif
// Get the frame index of the stack frame object that points to the location
// of dynamically allocated area on the stack.
int DynAllocFI = Cpu0FI->getDynAllocFI();
#if 0
// Update size of the maximum argument space.
// For O32, a minimum of four words (16 bytes) of argument space is
// allocated.
if (IsO32)
NextStackOffset = std::max(NextStackOffset, (unsigned)16);
#endif
unsigned MaxCallFrameSize = Cpu0FI->getMaxCallFrameSize();
if (MaxCallFrameSize < NextStackOffset) {
Cpu0FI->setMaxCallFrameSize(NextStackOffset);
// Set the offsets relative to $sp of the $gp restore slot and dynamically
// allocated stack space. These offsets must be aligned to a boundary
// determined by the stack alignment of the ABI.
unsigned StackAlignment = TFL->getStackAlignment();
NextStackOffset = (NextStackOffset + StackAlignment - 1) /
StackAlignment * StackAlignment;
if (Cpu0FI->needGPSaveRestore())
MFI->setObjectOffset(Cpu0FI->getGPFI(), NextStackOffset);
MFI->setObjectOffset(DynAllocFI, NextStackOffset);
}
// With EABI is it possible to have 16 args on registers.
SmallVector<std::pair<unsigned, SDValue>, 16> RegsToPass;
SmallVector<SDValue, 8> MemOpChains;
int FirstFI = -MFI->getNumFixedObjects() - 1, LastFI = 0;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
SDValue Arg = OutVals[i];
CCValAssign &VA = ArgLocs[i];
MVT ValVT = VA.getValVT(), LocVT = VA.getLocVT();
ISD::ArgFlagsTy Flags = Outs[i].Flags;
// ByVal Arg.
if (Flags.isByVal()) {
assert(Flags.getByValSize() &&
"ByVal args of size 0 should have been ignored by front-end.");
#if 0
if (IsO32)
WriteByValArg(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI,
MFI, DAG, Arg, VA, Flags, getPointerTy(),
Subtarget->isLittle());
#endif
#if 0
else
PassByValArg64(ByValChain, Chain, dl, RegsToPass, MemOpChains, LastFI,
MFI, DAG, Arg, VA, Flags, getPointerTy(),
Subtarget->isLittle());
#endif
continue;
}
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: llvm_unreachable("Unknown loc info!");
case CCValAssign::Full:
#if 0
if (VA.isRegLoc()) {
if ((ValVT == MVT::f32 && LocVT == MVT::i32) ||
(ValVT == MVT::f64 && LocVT == MVT::i64))
Arg = DAG.getNode(ISD::BITCAST, dl, LocVT, Arg);
else if (ValVT == MVT::f64 && LocVT == MVT::i32) {
SDValue Lo = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32,
Arg, DAG.getConstant(0, MVT::i32));
SDValue Hi = DAG.getNode(Cpu0ISD::ExtractElementF64, dl, MVT::i32,
Arg, DAG.getConstant(1, MVT::i32));
if (!Subtarget->isLittle())
std::swap(Lo, Hi);
unsigned LocRegLo = VA.getLocReg();
unsigned LocRegHigh = getNextIntArgReg(LocRegLo);
RegsToPass.push_back(std::make_pair(LocRegLo, Lo));
RegsToPass.push_back(std::make_pair(LocRegHigh, Hi));
continue;
}
}
#else
assert("CCValAssign::Full:"); // Gamma debug
#endif
break;
case CCValAssign::SExt:
Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, LocVT, Arg);
break;
case CCValAssign::ZExt:
Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, LocVT, Arg);
break;
case CCValAssign::AExt:
Arg = DAG.getNode(ISD::ANY_EXTEND, dl, LocVT, Arg);
break;
}
// Arguments that can be passed on register must be kept at
// RegsToPass vector
if (VA.isRegLoc()) {
RegsToPass.push_back(std::make_pair(VA.getLocReg(), Arg));
continue;
}
// Register can't get to this point...
assert(VA.isMemLoc());
// Create the frame index object for this incoming parameter
LastFI = MFI->CreateFixedObject(ValVT.getSizeInBits()/8,
VA.getLocMemOffset(), true);
SDValue PtrOff = DAG.getFrameIndex(LastFI, getPointerTy());
// emit ISD::STORE whichs stores the
// parameter value to a stack Location
MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
MachinePointerInfo(), false, false, 0));
}
// Extend range of indices of frame objects for outgoing arguments that were
// created during this function call. Skip this step if no such objects were
// created.
if (LastFI)
Cpu0FI->extendOutArgFIRange(FirstFI, LastFI);
// If a memcpy has been created to copy a byval arg to a stack, replace the
// chain input of CallSeqStart with ByValChain.
if (InChain != ByValChain)
DAG.UpdateNodeOperands(CallSeqStart.getNode(), ByValChain,
NextStackOffsetVal);
// Transform all store nodes into one single node because all store
// nodes are independent of each other.
if (!MemOpChains.empty())
Chain = DAG.getNode(ISD::TokenFactor, dl, MVT::Other,
&MemOpChains[0], MemOpChains.size());
// If the callee is a GlobalAddress/ExternalSymbol node (quite common, every
// direct call is) turn it into a TargetGlobalAddress/TargetExternalSymbol
// node so that legalize doesn't hack it.
unsigned char OpFlag;
#if 0 // cpu0 int 32 only
bool IsPICCall = (IsN64 || IsPIC); // true if calls are translated to jalr $25
#else
bool IsPICCall = IsPIC; // true if calls are translated to jalr $25
#endif
bool GlobalOrExternal = false;
SDValue CalleeLo;
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee)) {
if (IsPICCall && G->getGlobal()->hasInternalLinkage()) {
OpFlag = Cpu0II::MO_GOT;
#if 0
unsigned char LoFlag = IsO32 ? Cpu0II::MO_ABS_LO : Cpu0II::MO_GOT_OFST;
#else
unsigned char LoFlag = Cpu0II::MO_ABS_LO;
#endif
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(), 0,
OpFlag);
CalleeLo = DAG.getTargetGlobalAddress(G->getGlobal(), dl, getPointerTy(),
0, LoFlag);
} else {
OpFlag = IsPICCall ? Cpu0II::MO_GOT_CALL : Cpu0II::MO_NO_FLAG;
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), dl,
getPointerTy(), 0, OpFlag);
}
GlobalOrExternal = true;
}
else if (ExternalSymbolSDNode *S = dyn_cast<ExternalSymbolSDNode>(Callee)) {
if (!IsPIC) // static
OpFlag = Cpu0II::MO_NO_FLAG;
else // O32 & PIC
OpFlag = Cpu0II::MO_GOT_CALL;
Callee = DAG.getTargetExternalSymbol(S->getSymbol(), getPointerTy(),
OpFlag);
GlobalOrExternal = true;
}
SDValue InFlag;
// Create nodes that load address of callee and copy it to T9
if (IsPICCall) {
if (GlobalOrExternal) {
// Load callee address
Callee = DAG.getNode(Cpu0ISD::Wrapper, dl, getPointerTy(),
GetGlobalReg(DAG, getPointerTy()), Callee);
SDValue LoadValue = DAG.getLoad(getPointerTy(), dl, DAG.getEntryNode(),
Callee, MachinePointerInfo::getGOT(),
false, false, false, 0);
// Use GOT+LO if callee has internal linkage.
if (CalleeLo.getNode()) {
SDValue Lo = DAG.getNode(Cpu0ISD::Lo, dl, getPointerTy(), CalleeLo);
Callee = DAG.getNode(ISD::ADD, dl, getPointerTy(), LoadValue, Lo);
} else
Callee = LoadValue;
}
}
// T9 should contain the address of the callee function if
// -reloction-model=pic or it is an indirect call.
if (IsPICCall || !GlobalOrExternal) {
// copy to T9
unsigned T9Reg = Cpu0::T9;
Chain = DAG.getCopyToReg(Chain, dl, T9Reg, Callee, SDValue(0, 0));
InFlag = Chain.getValue(1);
Callee = DAG.getRegister(T9Reg, getPointerTy());
}
// Build a sequence of copy-to-reg nodes chained together with token
// chain and flag operands which copy the outgoing args into registers.
// The InFlag in necessary since all emitted instructions must be
// stuck together.
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) {
Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first,
RegsToPass[i].second, InFlag);
InFlag = Chain.getValue(1);
}
// Cpu0JmpLink = #chain, #target_address, #opt_in_flags...
// = Chain, Callee, Reg#1, Reg#2, ...
//
// Returns a chain & a flag for retval copy to use.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
SmallVector<SDValue, 8> Ops;
Ops.push_back(Chain);
Ops.push_back(Callee);
// Add argument registers to the end of the list so that they are
// known live into the call.
for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i)
Ops.push_back(DAG.getRegister(RegsToPass[i].first,
RegsToPass[i].second.getValueType()));
// Add a register mask operand representing the call-preserved registers.
const TargetRegisterInfo *TRI = getTargetMachine().getRegisterInfo();
const uint32_t *Mask = TRI->getCallPreservedMask(CallConv);
assert(Mask && "Missing call preserved mask for calling convention");
Ops.push_back(DAG.getRegisterMask(Mask));
if (InFlag.getNode())
Ops.push_back(InFlag);
Chain = DAG.getNode(Cpu0ISD::JmpLink, dl, NodeTys, &Ops[0], Ops.size());
InFlag = Chain.getValue(1);
// Create the CALLSEQ_END node.
Chain = DAG.getCALLSEQ_END(Chain,
DAG.getIntPtrConstant(NextStackOffset, true),
DAG.getIntPtrConstant(0, true), InFlag);
InFlag = Chain.getValue(1);
// Handle result values, copying them out of physregs into vregs that we
// return.
return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
Ins, dl, DAG, InVals);
#else
return InChain;
#endif
}
