Compile varargs functions for SPARCv9.
With a little help from the frontend, it looks like the standard va_*
intrinsics can do the job.
Also clean up an old bitcast hack in LowerVAARG that dealt with
unaligned double loads. Load SDNodes can specify an alignment now.
Still missing: Calling varargs functions with float arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179961 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Sparc/SparcISelLowering.cpp b/lib/Target/Sparc/SparcISelLowering.cpp
index b1732b1..e839d45 100644
--- a/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/lib/Target/Sparc/SparcISelLowering.cpp
@@ -543,6 +543,9 @@
getTargetMachine(), ArgLocs, *DAG.getContext());
CCInfo.AnalyzeFormalArguments(Ins, CC_Sparc64);
+ // The argument array begins at %fp+BIAS+128, after the register save area.
+ const unsigned ArgArea = 128;
+
for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
CCValAssign &VA = ArgLocs[i];
if (VA.isRegLoc()) {
@@ -586,7 +589,7 @@
assert(VA.isMemLoc());
// The CC_Sparc64_Full/Half functions compute stack offsets relative to the
// beginning of the arguments area at %fp+BIAS+128.
- unsigned Offset = VA.getLocMemOffset() + 128;
+ unsigned Offset = VA.getLocMemOffset() + ArgArea;
unsigned ValSize = VA.getValVT().getSizeInBits() / 8;
// Adjust offset for extended arguments, SPARC is big-endian.
// The caller will have written the full slot with extended bytes, but we
@@ -599,6 +602,41 @@
MachinePointerInfo::getFixedStack(FI),
false, false, false, 0));
}
+
+ if (!IsVarArg)
+ return Chain;
+
+ // This function takes variable arguments, some of which may have been passed
+ // in registers %i0-%i5. Variable floating point arguments are never passed
+ // in floating point registers. They go on %i0-%i5 or on the stack like
+ // integer arguments.
+ //
+ // The va_start intrinsic needs to know the offset to the first variable
+ // argument.
+ unsigned ArgOffset = CCInfo.getNextStackOffset();
+ SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
+ // Skip the 128 bytes of register save area.
+ FuncInfo->setVarArgsFrameOffset(ArgOffset + ArgArea +
+ Subtarget->getStackPointerBias());
+
+ // Save the variable arguments that were passed in registers.
+ // The caller is required to reserve stack space for 6 arguments regardless
+ // of how many arguments were actually passed.
+ SmallVector<SDValue, 8> OutChains;
+ for (; ArgOffset < 6*8; ArgOffset += 8) {
+ unsigned VReg = MF.addLiveIn(SP::I0 + ArgOffset/8, &SP::I64RegsRegClass);
+ SDValue VArg = DAG.getCopyFromReg(Chain, DL, VReg, MVT::i64);
+ int FI = MF.getFrameInfo()->CreateFixedObject(8, ArgOffset + ArgArea, true);
+ OutChains.push_back(DAG.getStore(Chain, DL, VArg,
+ DAG.getFrameIndex(FI, getPointerTy()),
+ MachinePointerInfo::getFixedStack(FI),
+ false, false, 0));
+ }
+
+ if (!OutChains.empty())
+ Chain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
+ &OutChains[0], OutChains.size());
+
return Chain;
}
@@ -1524,14 +1562,13 @@
// vastart just stores the address of the VarArgsFrameIndex slot into the
// memory location argument.
- DebugLoc dl = Op.getDebugLoc();
+ DebugLoc DL = Op.getDebugLoc();
SDValue Offset =
- DAG.getNode(ISD::ADD, dl, MVT::i32,
- DAG.getRegister(SP::I6, MVT::i32),
- DAG.getConstant(FuncInfo->getVarArgsFrameOffset(),
- MVT::i32));
+ DAG.getNode(ISD::ADD, DL, TLI.getPointerTy(),
+ DAG.getRegister(SP::I6, TLI.getPointerTy()),
+ DAG.getIntPtrConstant(FuncInfo->getVarArgsFrameOffset()));
const Value *SV = cast<SrcValueSDNode>(Op.getOperand(2))->getValue();
- return DAG.getStore(Op.getOperand(0), dl, Offset, Op.getOperand(1),
+ return DAG.getStore(Op.getOperand(0), DL, Offset, Op.getOperand(1),
MachinePointerInfo(SV), false, false, 0);
}
@@ -1540,33 +1577,22 @@
EVT VT = Node->getValueType(0);
SDValue InChain = Node->getOperand(0);
SDValue VAListPtr = Node->getOperand(1);
+ EVT PtrVT = VAListPtr.getValueType();
const Value *SV = cast<SrcValueSDNode>(Node->getOperand(2))->getValue();
- DebugLoc dl = Node->getDebugLoc();
- SDValue VAList = DAG.getLoad(MVT::i32, dl, InChain, VAListPtr,
+ DebugLoc DL = Node->getDebugLoc();
+ SDValue VAList = DAG.getLoad(PtrVT, DL, InChain, VAListPtr,
MachinePointerInfo(SV), false, false, false, 0);
- // Increment the pointer, VAList, to the next vaarg
- SDValue NextPtr = DAG.getNode(ISD::ADD, dl, MVT::i32, VAList,
- DAG.getConstant(VT.getSizeInBits()/8,
- MVT::i32));
- // Store the incremented VAList to the legalized pointer
- InChain = DAG.getStore(VAList.getValue(1), dl, NextPtr,
+ // Increment the pointer, VAList, to the next vaarg.
+ SDValue NextPtr = DAG.getNode(ISD::ADD, DL, PtrVT, VAList,
+ DAG.getIntPtrConstant(VT.getSizeInBits()/8));
+ // Store the incremented VAList to the legalized pointer.
+ InChain = DAG.getStore(VAList.getValue(1), DL, NextPtr,
VAListPtr, MachinePointerInfo(SV), false, false, 0);
- // Load the actual argument out of the pointer VAList, unless this is an
- // f64 load.
- if (VT != MVT::f64)
- return DAG.getLoad(VT, dl, InChain, VAList, MachinePointerInfo(),
- false, false, false, 0);
-
- // Otherwise, load it as i64, then do a bitconvert.
- SDValue V = DAG.getLoad(MVT::i64, dl, InChain, VAList, MachinePointerInfo(),
- false, false, false, 0);
-
- // Bit-Convert the value to f64.
- SDValue Ops[2] = {
- DAG.getNode(ISD::BITCAST, dl, MVT::f64, V),
- V.getValue(1)
- };
- return DAG.getMergeValues(Ops, 2, dl);
+ // Load the actual argument out of the pointer VAList.
+ // We can't count on greater alignment than the word size.
+ return DAG.getLoad(VT, DL, InChain, VAList, MachinePointerInfo(),
+ false, false, false,
+ std::min(PtrVT.getSizeInBits(), VT.getSizeInBits())/8);
}
static SDValue LowerDYNAMIC_STACKALLOC(SDValue Op, SelectionDAG &DAG) {