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Stack and register alignment of call arguments in the ELF ABI

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35083 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Nicolas Geoffray 2007-03-13 15:02:46 +00:00
parent bc1dbfce62
commit b2ec1cc6cb
1 changed files with 52 additions and 6 deletions
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58
lib/Target/PowerPC/PPCISelLowering.cpp
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@ -1132,6 +1132,7 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
MVT::ValueType PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
bool isPPC64 = PtrVT == MVT::i64;
bool isMachoABI = Subtarget.isMachoABI();
bool isELF_ABI = Subtarget.isELF_ABI();
unsigned PtrByteSize = isPPC64 ? 8 : 4;
unsigned ArgOffset = PPCFrameInfo::getLinkageSize(isPPC64, isMachoABI);
@ -1163,17 +1164,30 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
// Add DAG nodes to load the arguments or copy them out of registers. On
// entry to a function on PPC, the arguments start after the linkage area,
// although the first ones are often in registers.
//
// In the ELF ABI, GPRs and stack are double word align: an argument
// represented with two words (long long or double) must be copied to an
// even GPR_idx value or to an even ArgOffset value.
for (unsigned ArgNo = 0, e = Op.Val->getNumValues()-1; ArgNo != e; ++ArgNo) {
SDOperand ArgVal;
bool needsLoad = false;
MVT::ValueType ObjectVT = Op.getValue(ArgNo).getValueType();
unsigned ObjSize = MVT::getSizeInBits(ObjectVT)/8;
unsigned ArgSize = ObjSize;
unsigned Flags = cast<ConstantSDNode>(Op.getOperand(ArgNo+3))->getValue();
unsigned AlignFlag = 1 << ISD::ParamFlags::OrigAlignmentOffs;
// See if next argument requires stack alignment in ELF
bool Expand = (ObjectVT == MVT::f64) || ((ArgNo + 1 < e) &&
(cast<ConstantSDNode>(Op.getOperand(ArgNo+4))->getValue() & AlignFlag) &&
(!(Flags & AlignFlag)));
unsigned CurArgOffset = ArgOffset;
switch (ObjectVT) {
default: assert(0 && "Unhandled argument type!");
case MVT::i32:
// Double word align in ELF
if (Expand && isELF_ABI && !isPPC64) GPR_idx += (GPR_idx % 2);
if (GPR_idx != Num_GPR_Regs) {
unsigned VReg = RegMap->createVirtualRegister(&PPC::GPRCRegClass);
MF.addLiveIn(GPR[GPR_idx], VReg);
@ -1183,6 +1197,9 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
needsLoad = true;
ArgSize = PtrByteSize;
}
// Stack align in ELF
if (needsLoad && Expand && isELF_ABI && !isPPC64)
ArgOffset += ((ArgOffset/4) % 2) * PtrByteSize;
// All int arguments reserve stack space in Macho ABI.
if (isMachoABI || needsLoad) ArgOffset += PtrByteSize;
break;
@ -1204,7 +1221,7 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
case MVT::f64:
// Every 4 bytes of argument space consumes one of the GPRs available for
// argument passing.
if (GPR_idx != Num_GPR_Regs) {
if (GPR_idx != Num_GPR_Regs && isMachoABI) {
++GPR_idx;
if (ObjSize == 8 && GPR_idx != Num_GPR_Regs && !isPPC64)
++GPR_idx;
@ -1222,6 +1239,9 @@ static SDOperand LowerFORMAL_ARGUMENTS(SDOperand Op, SelectionDAG &DAG,
needsLoad = true;
}
// Stack align in ELF
if (needsLoad && Expand && isELF_ABI && !isPPC64)
ArgOffset += ((ArgOffset/4) % 2) * PtrByteSize;
// All FP arguments reserve stack space in Macho ABI.
if (isMachoABI || needsLoad) ArgOffset += isPPC64 ? 8 : ObjSize;
break;
@ -1324,6 +1344,7 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG,
unsigned NumOps = (Op.getNumOperands() - 5) / 2;
bool isMachoABI = Subtarget.isMachoABI();
bool isELF_ABI = Subtarget.isELF_ABI();
MVT::ValueType PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
bool isPPC64 = PtrVT == MVT::i64;
@ -1399,15 +1420,29 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG,
for (unsigned i = 0; i != NumOps; ++i) {
bool inMem = false;
SDOperand Arg = Op.getOperand(5+2*i);
unsigned Flags = cast<ConstantSDNode>(Op.getOperand(5+2*i+1))->getValue();
unsigned AlignFlag = 1 << ISD::ParamFlags::OrigAlignmentOffs;
// See if next argument requires stack alignment in ELF
unsigned next = 5+2*(i+1)+1;
bool Expand = (Arg.getValueType() == MVT::f64) || ((i + 1 < NumOps) &&
(cast<ConstantSDNode>(Op.getOperand(next))->getValue() & AlignFlag) &&
(!(Flags & AlignFlag)));
// PtrOff will be used to store the current argument to the stack if a
// register cannot be found for it.
SDOperand PtrOff = DAG.getConstant(ArgOffset, StackPtr.getValueType());
SDOperand PtrOff;
// Stack align in ELF
if (isELF_ABI && Expand && !isPPC64)
PtrOff = DAG.getConstant(ArgOffset + ((ArgOffset/4) % 2) * PtrByteSize,
StackPtr.getValueType());
else
PtrOff = DAG.getConstant(ArgOffset, StackPtr.getValueType());
PtrOff = DAG.getNode(ISD::ADD, PtrVT, StackPtr, PtrOff);
// On PPC64, promote integers to 64-bit values.
if (isPPC64 && Arg.getValueType() == MVT::i32) {
unsigned Flags = cast<ConstantSDNode>(Op.getOperand(5+2*i+1))->getValue();
unsigned ExtOp = (Flags & 1) ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
Arg = DAG.getNode(ExtOp, MVT::i64, Arg);
@ -1417,13 +1452,21 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG,
default: assert(0 && "Unexpected ValueType for argument!");
case MVT::i32:
case MVT::i64:
// Double word align in ELF
if (isELF_ABI && Expand && !isPPC64) GPR_idx += (GPR_idx % 2);
if (GPR_idx != NumGPRs) {
RegsToPass.push_back(std::make_pair(GPR[GPR_idx++], Arg));
} else {
MemOpChains.push_back(DAG.getStore(Chain, Arg, PtrOff, NULL, 0));
inMem = true;
}
if (inMem || isMachoABI) ArgOffset += PtrByteSize;
if (inMem || isMachoABI) {
// Stack align in ELF
if (isELF_ABI && Expand && !isPPC64)
ArgOffset += ((ArgOffset/4) % 2) * PtrByteSize;
ArgOffset += PtrByteSize;
}
break;
case MVT::f32:
case MVT::f64:
@ -1472,6 +1515,9 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG,
inMem = true;
}
if (inMem || isMachoABI) {
// Stack align in ELF
if (isELF_ABI && Expand && !isPPC64)
ArgOffset += ((ArgOffset/4) % 2) * PtrByteSize;
if (isPPC64)
ArgOffset += 8;
else
@ -1503,7 +1549,7 @@ static SDOperand LowerCALL(SDOperand Op, SelectionDAG &DAG,
}
// With the ELF ABI, set CR6 to true if this is a vararg call.
if (isVarArg && !isMachoABI) {
if (isVarArg && isELF_ABI) {
SDOperand SetCR(DAG.getTargetNode(PPC::SETCR, MVT::i32), 0);
Chain = DAG.getCopyToReg(Chain, PPC::CR6, SetCR, InFlag);
InFlag = Chain.getValue(1);