Add CALL lowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70727 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Anton Korobeynikov 2009-05-03 13:07:31 +00:00
parent 01e0e8d119
commit 4428885c5a
3 changed files with 193 additions and 4 deletions

View File

@ -70,8 +70,9 @@ MSP430TargetLowering::MSP430TargetLowering(MSP430TargetMachine &tm) :
SDValue MSP430TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
case ISD::FORMAL_ARGUMENTS: return LowerFORMAL_ARGUMENTS(Op, DAG);
case ISD::SRA: return LowerShifts(Op, DAG);
case ISD::RET: return LowerRET(Op, DAG);
case ISD::SRA: return LowerShifts(Op, DAG);
case ISD::RET: return LowerRET(Op, DAG);
case ISD::CALL: return LowerCALL(Op, DAG);
default:
assert(0 && "unimplemented operand");
return SDValue();
@ -96,6 +97,18 @@ SDValue MSP430TargetLowering::LowerFORMAL_ARGUMENTS(SDValue Op,
}
}
SDValue MSP430TargetLowering::LowerCALL(SDValue Op, SelectionDAG &DAG) {
CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
unsigned CallingConv = TheCall->getCallingConv();
switch (CallingConv) {
default:
assert(0 && "Unsupported calling convention");
case CallingConv::Fast:
case CallingConv::C:
return LowerCCCCallTo(Op, DAG, CallingConv);
}
}
/// LowerCCCArguments - transform physical registers into virtual registers and
/// generate load operations for arguments places on the stack.
// FIXME: struct return stuff
@ -225,6 +238,166 @@ SDValue MSP430TargetLowering::LowerRET(SDValue Op, SelectionDAG &DAG) {
return DAG.getNode(MSP430ISD::RET_FLAG, dl, MVT::Other, Chain);
}
/// LowerCCCCallTo - functions arguments are copied from virtual regs to
/// (physical regs)/(stack frame), CALLSEQ_START and CALLSEQ_END are emitted.
/// TODO: sret.
SDValue MSP430TargetLowering::LowerCCCCallTo(SDValue Op, SelectionDAG &DAG,
unsigned CC) {
CallSDNode *TheCall = cast<CallSDNode>(Op.getNode());
SDValue Chain = TheCall->getChain();
SDValue Callee = TheCall->getCallee();
bool isVarArg = TheCall->isVarArg();
DebugLoc dl = Op.getDebugLoc();
// Analyze operands of the call, assigning locations to each operand.
SmallVector<CCValAssign, 16> ArgLocs;
CCState CCInfo(CC, isVarArg, getTargetMachine(), ArgLocs);
CCInfo.AnalyzeCallOperands(TheCall, CC_MSP430);
// Get a count of how many bytes are to be pushed on the stack.
unsigned NumBytes = CCInfo.getNextStackOffset();
Chain = DAG.getCALLSEQ_START(Chain ,DAG.getConstant(NumBytes,
getPointerTy(), true));
SmallVector<std::pair<unsigned, SDValue>, 4> RegsToPass;
SmallVector<SDValue, 12> MemOpChains;
SDValue StackPtr;
// Walk the register/memloc assignments, inserting copies/loads.
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
// Arguments start after the 5 first operands of ISD::CALL
SDValue Arg = TheCall->getArg(i);
// Promote the value if needed.
switch (VA.getLocInfo()) {
default: assert(0 && "Unknown loc info!");
case CCValAssign::Full: break;
case CCValAssign::SExt:
Arg = DAG.getNode(ISD::SIGN_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::ZExt:
Arg = DAG.getNode(ISD::ZERO_EXTEND, dl, VA.getLocVT(), Arg);
break;
case CCValAssign::AExt:
Arg = DAG.getNode(ISD::ANY_EXTEND, dl, VA.getLocVT(), 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));
} else {
assert(VA.isMemLoc());
if (StackPtr.getNode() == 0)
StackPtr = DAG.getCopyFromReg(Chain, dl, MSP430::SPW, getPointerTy());
SDValue PtrOff = DAG.getNode(ISD::ADD, dl, getPointerTy(),
StackPtr,
DAG.getIntPtrConstant(VA.getLocMemOffset()));
MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
PseudoSourceValue::getStack(),
VA.getLocMemOffset()));
}
}
// 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());
// 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 emited instructions must be stuck together.
SDValue InFlag;
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);
}
// If the callee is a GlobalAddress node (quite common, every direct call is)
// turn it into a TargetGlobalAddress node so that legalize doesn't hack it.
// Likewise ExternalSymbol -> TargetExternalSymbol.
if (GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
Callee = DAG.getTargetGlobalAddress(G->getGlobal(), MVT::i16);
else if (ExternalSymbolSDNode *E = dyn_cast<ExternalSymbolSDNode>(Callee))
Callee = DAG.getTargetExternalSymbol(E->getSymbol(), MVT::i16);
// Returns a chain & a flag for retval copy to use.
SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Flag);
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()));
if (InFlag.getNode())
Ops.push_back(InFlag);
Chain = DAG.getNode(MSP430ISD::CALL, dl, NodeTys, &Ops[0], Ops.size());
InFlag = Chain.getValue(1);
// Create the CALLSEQ_END node.
Chain = DAG.getCALLSEQ_END(Chain,
DAG.getConstant(NumBytes, getPointerTy(), true),
DAG.getConstant(0, getPointerTy(), true),
InFlag);
InFlag = Chain.getValue(1);
// Handle result values, copying them out of physregs into vregs that we
// return.
return SDValue(LowerCallResult(Chain, InFlag, TheCall, CC, DAG),
Op.getResNo());
}
/// LowerCallResult - Lower the result values of an ISD::CALL into the
/// appropriate copies out of appropriate physical registers. This assumes that
/// Chain/InFlag are the input chain/flag to use, and that TheCall is the call
/// being lowered. Returns a SDNode with the same number of values as the
/// ISD::CALL.
SDNode*
MSP430TargetLowering::LowerCallResult(SDValue Chain, SDValue InFlag,
CallSDNode *TheCall,
unsigned CallingConv,
SelectionDAG &DAG) {
bool isVarArg = TheCall->isVarArg();
DebugLoc dl = TheCall->getDebugLoc();
// Assign locations to each value returned by this call.
SmallVector<CCValAssign, 16> RVLocs;
CCState CCInfo(CallingConv, isVarArg, getTargetMachine(), RVLocs);
CCInfo.AnalyzeCallResult(TheCall, RetCC_MSP430);
SmallVector<SDValue, 8> ResultVals;
// Copy all of the result registers out of their specified physreg.
for (unsigned i = 0; i != RVLocs.size(); ++i) {
Chain = DAG.getCopyFromReg(Chain, dl, RVLocs[i].getLocReg(),
RVLocs[i].getValVT(), InFlag).getValue(1);
InFlag = Chain.getValue(2);
ResultVals.push_back(Chain.getValue(0));
}
ResultVals.push_back(Chain);
// Merge everything together with a MERGE_VALUES node.
return DAG.getNode(ISD::MERGE_VALUES, dl, TheCall->getVTList(),
&ResultVals[0], ResultVals.size()).getNode();
}
SDValue MSP430TargetLowering::LowerShifts(SDValue Op,
SelectionDAG &DAG) {
assert(Op.getOpcode() == ISD::SRA && "Only SRA is currently supported.");
@ -255,4 +428,3 @@ const char *MSP430TargetLowering::getTargetNodeName(unsigned Opcode) const {
case MSP430ISD::RRA: return "MSP430ISD::RRA";
}
}

View File

@ -28,7 +28,11 @@ namespace llvm {
RET_FLAG,
/// Y = RRA X, rotate right arithmetically
RRA
RRA,
/// CALL/TAILCALL - These operations represent an abstract call
/// instruction, which includes a bunch of information.
CALL
};
}
@ -47,9 +51,18 @@ namespace llvm {
virtual const char *getTargetNodeName(unsigned Opcode) const;
SDValue LowerFORMAL_ARGUMENTS(SDValue Op, SelectionDAG &DAG);
SDValue LowerCALL(SDValue Op, SelectionDAG &DAG);
SDValue LowerRET(SDValue Op, SelectionDAG &DAG);
SDValue LowerCCCArguments(SDValue Op, SelectionDAG &DAG);
SDValue LowerShifts(SDValue Op, SelectionDAG &DAG);
SDValue LowerCCCCallTo(SDValue Op, SelectionDAG &DAG,
unsigned CC);
SDNode* LowerCallResult(SDValue Chain, SDValue InFlag,
CallSDNode *TheCall,
unsigned CallingConv, SelectionDAG &DAG);
private:
const MSP430Subtarget &Subtarget;
const MSP430TargetMachine &TM;

View File

@ -22,6 +22,7 @@ class SDTCisI16<int OpNum> : SDTCisVT<OpNum, i16>;
//===----------------------------------------------------------------------===//
// Type Profiles.
//===----------------------------------------------------------------------===//
def SDT_MSP430Call : SDTypeProfile<0, -1, [SDTCisVT<0, iPTR>]>;
//===----------------------------------------------------------------------===//
// MSP430 Specific Node Definitions.
@ -31,6 +32,9 @@ def MSP430retflag : SDNode<"MSP430ISD::RET_FLAG", SDTNone,
def MSP430rra : SDNode<"MSP430ISD::RRA", SDTIntUnaryOp, []>;
def MSP430call : SDNode<"MSP430ISD::CALL", SDT_MSP430Call,
[SDNPHasChain, SDNPOutFlag, SDNPOptInFlag]>;
//===----------------------------------------------------------------------===//
// MSP430 Operand Definitions.
//===----------------------------------------------------------------------===//