remove RET hack, add proper support for rets (watching out for ret voids)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25486 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Duraid Madina 2006-01-20 20:24:31 +00:00
parent 14d9b20b78
commit bea99471c7
4 changed files with 89 additions and 56 deletions

View File

@ -585,57 +585,6 @@ SDOperand IA64DAGToDAGISel::Select(SDOperand Op) {
getI64Imm(Amt), Select(N->getOperand(0)));
}
case ISD::RET: {
SDOperand Chain = Select(N->getOperand(0)); // Token chain.
SDOperand InFlag;
switch (N->getNumOperands()) {
default:
assert(0 && "Unknown return instruction!");
case 2: {
SDOperand RetVal = Select(N->getOperand(1));
switch (RetVal.getValueType()) {
default: assert(0 && "I don't know how to return this type! (promote?)");
// FIXME: do I need to add support for bools here?
// (return '0' or '1' in r8, basically...)
//
// FIXME: need to round floats - 80 bits is bad, the tester
// told me so
case MVT::i64:
// we mark r8 as live on exit up above in LowerArguments()
// BuildMI(BB, IA64::MOV, 1, IA64::r8).addReg(Tmp1);
Chain = CurDAG->getCopyToReg(Chain, IA64::r8, RetVal);
InFlag = Chain.getValue(1);
break;
case MVT::f64:
// we mark F8 as live on exit up above in LowerArguments()
// BuildMI(BB, IA64::FMOV, 1, IA64::F8).addReg(Tmp1);
Chain = CurDAG->getCopyToReg(Chain, IA64::F8, RetVal);
InFlag = Chain.getValue(1);
break;
}
break;
}
case 1:
break;
}
// we need to copy VirtGPR (the vreg (to become a real reg)) that holds
// the output of this function's alloc instruction back into ar.pfs
// before we return. this copy must not float up above the last
// outgoing call in this function!!!
SDOperand AR_PFSVal = CurDAG->getCopyFromReg(Chain, IA64Lowering.VirtGPR,
MVT::i64);
Chain = AR_PFSVal.getValue(1);
Chain = CurDAG->getCopyToReg(Chain, IA64::AR_PFS, AR_PFSVal);
// and then just emit a 'ret' instruction
// before returning, restore the ar.pfs register (set by the 'alloc' up top)
// BuildMI(BB, IA64::MOV, 1).addReg(IA64::AR_PFS).addReg(IA64Lowering.VirtGPR);
//
return CurDAG->SelectNodeTo(N, IA64::RET, MVT::Other, Chain);
}
case ISD::BR:
// FIXME: we don't need long branches all the time!
return CurDAG->SelectNodeTo(N, IA64::BRL_NOTCALL, MVT::Other,

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@ -39,6 +39,11 @@ IA64TargetLowering::IA64TargetLowering(TargetMachine &TM)
setOperationAction(ISD::BRTWOWAY_CC , MVT::Other, Expand);
setOperationAction(ISD::FP_ROUND_INREG , MVT::f32 , Expand);
// We need to handle ISD::RET for void functions ourselves,
// so we get a chance to restore ar.pfs before adding a
// br.ret insn
setOperationAction(ISD::RET, MVT::Other, Custom);
setSetCCResultType(MVT::i1);
setShiftAmountType(MVT::i64);
@ -101,6 +106,7 @@ const char *IA64TargetLowering::getTargetNodeName(unsigned Opcode) const {
default: return 0;
case IA64ISD::GETFD: return "IA64ISD::GETFD";
case IA64ISD::BRCALL: return "IA64ISD::BRCALL";
case IA64ISD::RET_FLAG: return "IA64ISD::RET_FLAG";
}
}
@ -524,6 +530,44 @@ IA64TargetLowering::LowerCallTo(SDOperand Chain,
return std::make_pair(RetVal, Chain);
}
SDOperand IA64TargetLowering::LowerReturnTo(SDOperand Chain, SDOperand Op,
SelectionDAG &DAG) {
SDOperand Copy, InFlag;
SDOperand AR_PFSVal = DAG.getCopyFromReg(Chain, this->VirtGPR,
MVT::i64);
Chain = AR_PFSVal.getValue(1);
switch (Op.getValueType()) {
default: assert(0 && "Unknown type to return! (promote?)");
case MVT::i64:
Copy = DAG.getCopyToReg(Chain, IA64::r8, Op, InFlag);
break;
case MVT::f64:
Copy = DAG.getCopyToReg(Chain, IA64::F8, Op, InFlag);
break;
}
Chain = Copy.getValue(0);
InFlag = Copy.getValue(1);
// we need to copy VirtGPR (the vreg (to become a real reg)) that holds
// the output of this function's alloc instruction back into ar.pfs
// before we return. this copy must not float up above the last
// outgoing call in this function - we flag this to the ret instruction
Chain = DAG.getCopyToReg(Chain, IA64::AR_PFS, AR_PFSVal, InFlag);
InFlag = Chain.getValue(1);
// and then just emit a 'ret' instruction
std::vector<MVT::ValueType> NodeTys;
std::vector<SDOperand> RetOperands;
NodeTys.push_back(MVT::Other);
NodeTys.push_back(MVT::Flag);
RetOperands.push_back(Chain);
RetOperands.push_back(InFlag);
return DAG.getNode(IA64ISD::RET_FLAG, NodeTys, RetOperands);
// return DAG.getNode(IA64ISD::RET_FLAG, MVT::Other, MVT::Other, Copy, Chain, InFlag);
}
SDOperand
IA64TargetLowering::LowerVAStart(SDOperand Chain, SDOperand VAListP,
Value *VAListV, SelectionDAG &DAG) {
@ -566,3 +610,25 @@ LowerFrameReturnAddress(bool isFrameAddress, SDOperand Chain, unsigned Depth,
abort();
}
SDOperand IA64TargetLowering::
LowerOperation(SDOperand Op, SelectionDAG &DAG) {
switch (Op.getOpcode()) {
default: assert(0 && "Should not custom lower this!");
case ISD::RET: { // the DAGgy stuff takes care of
// restoring ar.pfs before adding a br.ret for functions
// that return something, but we need to take care of stuff
// that returns void manually, so here it is:
assert(Op.getNumOperands()==1 &&
"trying to custom lower a return other than void! (numops!=1)");
SDOperand Chain = Op.getOperand(0);
SDOperand AR_PFSVal = DAG.getCopyFromReg(Chain, this->VirtGPR,
MVT::i64);
Chain = AR_PFSVal.getValue(1);
Chain = DAG.getCopyToReg(Chain, IA64::AR_PFS, AR_PFSVal);
// and then just emit a 'ret' instruction
return DAG.getNode(IA64ISD::RET_FLAG, MVT::Other, Chain);
}
}
}

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@ -30,7 +30,10 @@ namespace llvm {
GETFD,
// TODO: explain this hack
BRCALL
BRCALL,
// RET_FLAG - Return with a flag operand
RET_FLAG
};
}
@ -64,9 +67,18 @@ namespace llvm {
bool isTailCall, SDOperand Callee, ArgListTy &Args,
SelectionDAG &DAG);
/// LowerReturnTo - This spits out restore-previous-frame-state+br.ret
/// instructions
virtual SDOperand LowerReturnTo(SDOperand Chain, SDOperand Op,
SelectionDAG &DAG);
/// LowerOperation - for custom lowering specific ops
/// (currently, only "ret void")
virtual SDOperand LowerOperation(SDOperand Op, SelectionDAG &DAG);
virtual SDOperand LowerVAStart(SDOperand Chain, SDOperand VAListP,
Value *VAListV, SelectionDAG &DAG);
virtual std::pair<SDOperand,SDOperand>
LowerVAArg(SDOperand Chain, SDOperand VAListP, Value *VAListV,
const Type *ArgTy, SelectionDAG &DAG);

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@ -21,6 +21,10 @@ include "IA64InstrFormats.td"
def IA64getfd : SDNode<"IA64ISD::GETFD", SDTFPToIntOp, []>;
def SDT_IA64RetFlag : SDTypeProfile<0, 0, []>;
def retflag : SDNode<"IA64ISD::RET_FLAG", SDT_IA64RetFlag,
[SDNPHasChain, SDNPOptInFlag]>;
//===---------
def u2imm : Operand<i8>;
@ -717,7 +721,9 @@ let isCall = 1, noResults = 1, /* isTerminator = 1, isBranch = 1, */
"($qp) br.cond.call.sptk $dst;;">;
}
// Return branch:
let isTerminator = 1, isReturn = 1, noResults = 1 in
def RET : RawForm<0x03, 0xb0, (ops), "br.ret.sptk.many rp;;">; // return
def RET : AForm_DAG<0x03, 0x0b, (ops),
"br.ret.sptk.many rp;;",
[(retflag)]>; // return
def : Pat<(ret), (RET)>;