[llvm-commits] [llvm] r165336 - in /llvm/trunk/lib/Target/PowerPC: PPCISelLowering.cpp PPCISelLowering.h
Bill Schmidt
wschmidt at linux.vnet.ibm.com
Fri Oct 5 14:27:08 PDT 2012
Author: wschmidt
Date: Fri Oct 5 16:27:08 2012
New Revision: 165336
URL: http://llvm.org/viewvc/llvm-project?rev=165336&view=rev
Log:
This patch splits apart PPCISelLowering::LowerFormalArguments_Darwin_Or_64SVR4
into separate versions for the Darwin and 64-bit SVR4 ABIs. This will
facilitate doing more major surgery on the 64-bit SVR4 ABI in the near future.
Modified:
llvm/trunk/lib/Target/PowerPC/PPCISelLowering.cpp
llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h
Modified: llvm/trunk/lib/Target/PowerPC/PPCISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelLowering.cpp?rev=165336&r1=165335&r2=165336&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelLowering.cpp Fri Oct 5 16:27:08 2012
@@ -1716,12 +1716,16 @@
DebugLoc dl, SelectionDAG &DAG,
SmallVectorImpl<SDValue> &InVals)
const {
- if (PPCSubTarget.isSVR4ABI() && !PPCSubTarget.isPPC64()) {
- return LowerFormalArguments_32SVR4(Chain, CallConv, isVarArg, Ins,
- dl, DAG, InVals);
+ if (PPCSubTarget.isSVR4ABI()) {
+ if (PPCSubTarget.isPPC64())
+ return LowerFormalArguments_64SVR4(Chain, CallConv, isVarArg, Ins,
+ dl, DAG, InVals);
+ else
+ return LowerFormalArguments_32SVR4(Chain, CallConv, isVarArg, Ins,
+ dl, DAG, InVals);
} else {
- return LowerFormalArguments_Darwin_Or_64SVR4(Chain, CallConv, isVarArg, Ins,
- dl, DAG, InVals);
+ return LowerFormalArguments_Darwin(Chain, CallConv, isVarArg, Ins,
+ dl, DAG, InVals);
}
}
@@ -1944,7 +1948,295 @@
}
SDValue
-PPCTargetLowering::LowerFormalArguments_Darwin_Or_64SVR4(
+PPCTargetLowering::LowerFormalArguments_64SVR4(
+ SDValue Chain,
+ CallingConv::ID CallConv, bool isVarArg,
+ const SmallVectorImpl<ISD::InputArg>
+ &Ins,
+ DebugLoc dl, SelectionDAG &DAG,
+ SmallVectorImpl<SDValue> &InVals) const {
+ // TODO: add description of PPC stack frame format, or at least some docs.
+ //
+ MachineFunction &MF = DAG.getMachineFunction();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+
+ EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
+ // Potential tail calls could cause overwriting of argument stack slots.
+ bool isImmutable = !(getTargetMachine().Options.GuaranteedTailCallOpt &&
+ (CallConv == CallingConv::Fast));
+ unsigned PtrByteSize = 8;
+
+ unsigned ArgOffset = PPCFrameLowering::getLinkageSize(true, true);
+ // Area that is at least reserved in caller of this function.
+ unsigned MinReservedArea = ArgOffset;
+
+ static const uint16_t GPR[] = {
+ PPC::X3, PPC::X4, PPC::X5, PPC::X6,
+ PPC::X7, PPC::X8, PPC::X9, PPC::X10,
+ };
+
+ static const uint16_t *FPR = GetFPR();
+
+ static const uint16_t VR[] = {
+ PPC::V2, PPC::V3, PPC::V4, PPC::V5, PPC::V6, PPC::V7, PPC::V8,
+ PPC::V9, PPC::V10, PPC::V11, PPC::V12, PPC::V13
+ };
+
+ const unsigned Num_GPR_Regs = array_lengthof(GPR);
+ const unsigned Num_FPR_Regs = 13;
+ const unsigned Num_VR_Regs = array_lengthof(VR);
+
+ unsigned GPR_idx = 0, FPR_idx = 0, VR_idx = 0;
+
+ // 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.
+
+ SmallVector<SDValue, 8> MemOps;
+ unsigned nAltivecParamsAtEnd = 0;
+ Function::const_arg_iterator FuncArg = MF.getFunction()->arg_begin();
+ for (unsigned ArgNo = 0, e = Ins.size(); ArgNo != e; ++ArgNo, ++FuncArg) {
+ SDValue ArgVal;
+ bool needsLoad = false;
+ EVT ObjectVT = Ins[ArgNo].VT;
+ unsigned ObjSize = ObjectVT.getSizeInBits()/8;
+ unsigned ArgSize = ObjSize;
+ ISD::ArgFlagsTy Flags = Ins[ArgNo].Flags;
+
+ unsigned CurArgOffset = ArgOffset;
+
+ // Varargs or 64 bit Altivec parameters are padded to a 16 byte boundary.
+ if (ObjectVT==MVT::v4f32 || ObjectVT==MVT::v4i32 ||
+ ObjectVT==MVT::v8i16 || ObjectVT==MVT::v16i8) {
+ if (isVarArg) {
+ MinReservedArea = ((MinReservedArea+15)/16)*16;
+ MinReservedArea += CalculateStackSlotSize(ObjectVT,
+ Flags,
+ PtrByteSize);
+ } else
+ nAltivecParamsAtEnd++;
+ } else
+ // Calculate min reserved area.
+ MinReservedArea += CalculateStackSlotSize(Ins[ArgNo].VT,
+ Flags,
+ PtrByteSize);
+
+ // FIXME the codegen can be much improved in some cases.
+ // We do not have to keep everything in memory.
+ if (Flags.isByVal()) {
+ // ObjSize is the true size, ArgSize rounded up to multiple of registers.
+ ObjSize = Flags.getByValSize();
+ ArgSize = ((ObjSize + PtrByteSize - 1)/PtrByteSize) * PtrByteSize;
+ // All aggregates smaller than 8 bytes must be passed right-justified.
+ if (ObjSize==1 || ObjSize==2) {
+ CurArgOffset = CurArgOffset + (4 - ObjSize);
+ }
+ // The value of the object is its address.
+ int FI = MFI->CreateFixedObject(ObjSize, CurArgOffset, true);
+ SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
+ InVals.push_back(FIN);
+ if (ObjSize==1 || ObjSize==2 || ObjSize==4) {
+ if (GPR_idx != Num_GPR_Regs) {
+ unsigned VReg;
+ VReg = MF.addLiveIn(GPR[GPR_idx], &PPC::G8RCRegClass);
+ SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, PtrVT);
+ EVT ObjType = (ObjSize == 1 ? MVT::i8 :
+ (ObjSize == 2 ? MVT::i16 : MVT::i32));
+ SDValue Store = DAG.getTruncStore(Val.getValue(1), dl, Val, FIN,
+ MachinePointerInfo(FuncArg,
+ CurArgOffset),
+ ObjType, false, false, 0);
+ MemOps.push_back(Store);
+ ++GPR_idx;
+ }
+
+ ArgOffset += PtrByteSize;
+
+ continue;
+ }
+ for (unsigned j = 0; j < ArgSize; j += PtrByteSize) {
+ // Store whatever pieces of the object are in registers
+ // to memory. ArgOffset will be the address of the beginning
+ // of the object.
+ if (GPR_idx != Num_GPR_Regs) {
+ unsigned VReg;
+ VReg = MF.addLiveIn(GPR[GPR_idx], &PPC::G8RCRegClass);
+ int FI = MFI->CreateFixedObject(PtrByteSize, ArgOffset, true);
+ SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
+ SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, PtrVT);
+ SDValue Shifted = Val;
+
+ // For 64-bit SVR4, small structs come in right-adjusted.
+ // Shift them left so the following logic works as expected.
+ if (ObjSize < 8) {
+ SDValue ShiftAmt = DAG.getConstant(64 - 8 * ObjSize, PtrVT);
+ Shifted = DAG.getNode(ISD::SHL, dl, PtrVT, Val, ShiftAmt);
+ }
+
+ SDValue Store = DAG.getStore(Val.getValue(1), dl, Shifted, FIN,
+ MachinePointerInfo(FuncArg, ArgOffset),
+ false, false, 0);
+ MemOps.push_back(Store);
+ ++GPR_idx;
+ ArgOffset += PtrByteSize;
+ } else {
+ ArgOffset += ArgSize - (ArgOffset-CurArgOffset);
+ break;
+ }
+ }
+ continue;
+ }
+
+ switch (ObjectVT.getSimpleVT().SimpleTy) {
+ default: llvm_unreachable("Unhandled argument type!");
+ case MVT::i32:
+ case MVT::i64:
+ if (GPR_idx != Num_GPR_Regs) {
+ unsigned VReg = MF.addLiveIn(GPR[GPR_idx], &PPC::G8RCRegClass);
+ ArgVal = DAG.getCopyFromReg(Chain, dl, VReg, MVT::i64);
+
+ if (ObjectVT == MVT::i32) {
+ // PPC64 passes i8, i16, and i32 values in i64 registers. Promote
+ // value to MVT::i64 and then truncate to the correct register size.
+ if (Flags.isSExt())
+ ArgVal = DAG.getNode(ISD::AssertSext, dl, MVT::i64, ArgVal,
+ DAG.getValueType(ObjectVT));
+ else if (Flags.isZExt())
+ ArgVal = DAG.getNode(ISD::AssertZext, dl, MVT::i64, ArgVal,
+ DAG.getValueType(ObjectVT));
+
+ ArgVal = DAG.getNode(ISD::TRUNCATE, dl, MVT::i32, ArgVal);
+ }
+
+ ++GPR_idx;
+ } else {
+ needsLoad = true;
+ ArgSize = PtrByteSize;
+ }
+ ArgOffset += 8;
+ break;
+
+ case MVT::f32:
+ case MVT::f64:
+ // Every 8 bytes of argument space consumes one of the GPRs available for
+ // argument passing.
+ if (GPR_idx != Num_GPR_Regs) {
+ ++GPR_idx;
+ }
+ if (FPR_idx != Num_FPR_Regs) {
+ unsigned VReg;
+
+ if (ObjectVT == MVT::f32)
+ VReg = MF.addLiveIn(FPR[FPR_idx], &PPC::F4RCRegClass);
+ else
+ VReg = MF.addLiveIn(FPR[FPR_idx], &PPC::F8RCRegClass);
+
+ ArgVal = DAG.getCopyFromReg(Chain, dl, VReg, ObjectVT);
+ ++FPR_idx;
+ } else {
+ needsLoad = true;
+ }
+
+ ArgOffset += 8;
+ break;
+ case MVT::v4f32:
+ case MVT::v4i32:
+ case MVT::v8i16:
+ case MVT::v16i8:
+ // Note that vector arguments in registers don't reserve stack space,
+ // except in varargs functions.
+ if (VR_idx != Num_VR_Regs) {
+ unsigned VReg = MF.addLiveIn(VR[VR_idx], &PPC::VRRCRegClass);
+ ArgVal = DAG.getCopyFromReg(Chain, dl, VReg, ObjectVT);
+ if (isVarArg) {
+ while ((ArgOffset % 16) != 0) {
+ ArgOffset += PtrByteSize;
+ if (GPR_idx != Num_GPR_Regs)
+ GPR_idx++;
+ }
+ ArgOffset += 16;
+ GPR_idx = std::min(GPR_idx+4, Num_GPR_Regs); // FIXME correct for ppc64?
+ }
+ ++VR_idx;
+ } else {
+ // Vectors are aligned.
+ ArgOffset = ((ArgOffset+15)/16)*16;
+ CurArgOffset = ArgOffset;
+ ArgOffset += 16;
+ needsLoad = true;
+ }
+ break;
+ }
+
+ // We need to load the argument to a virtual register if we determined
+ // above that we ran out of physical registers of the appropriate type.
+ if (needsLoad) {
+ int FI = MFI->CreateFixedObject(ObjSize,
+ CurArgOffset + (ArgSize - ObjSize),
+ isImmutable);
+ SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
+ ArgVal = DAG.getLoad(ObjectVT, dl, Chain, FIN, MachinePointerInfo(),
+ false, false, false, 0);
+ }
+
+ InVals.push_back(ArgVal);
+ }
+
+ // Set the size that is at least reserved in caller of this function. Tail
+ // call optimized function's reserved stack space needs to be aligned so that
+ // taking the difference between two stack areas will result in an aligned
+ // stack.
+ PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
+ // Add the Altivec parameters at the end, if needed.
+ if (nAltivecParamsAtEnd) {
+ MinReservedArea = ((MinReservedArea+15)/16)*16;
+ MinReservedArea += 16*nAltivecParamsAtEnd;
+ }
+ MinReservedArea =
+ std::max(MinReservedArea,
+ PPCFrameLowering::getMinCallFrameSize(true, true));
+ unsigned TargetAlign
+ = DAG.getMachineFunction().getTarget().getFrameLowering()->
+ getStackAlignment();
+ unsigned AlignMask = TargetAlign-1;
+ MinReservedArea = (MinReservedArea + AlignMask) & ~AlignMask;
+ FI->setMinReservedArea(MinReservedArea);
+
+ // If the function takes variable number of arguments, make a frame index for
+ // the start of the first vararg value... for expansion of llvm.va_start.
+ if (isVarArg) {
+ int Depth = ArgOffset;
+
+ FuncInfo->setVarArgsFrameIndex(
+ MFI->CreateFixedObject(PtrVT.getSizeInBits()/8,
+ Depth, true));
+ SDValue FIN = DAG.getFrameIndex(FuncInfo->getVarArgsFrameIndex(), PtrVT);
+
+ // If this function is vararg, store any remaining integer argument regs
+ // to their spots on the stack so that they may be loaded by deferencing the
+ // result of va_next.
+ for (; GPR_idx != Num_GPR_Regs; ++GPR_idx) {
+ unsigned VReg = MF.addLiveIn(GPR[GPR_idx], &PPC::G8RCRegClass);
+ SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, PtrVT);
+ SDValue Store = DAG.getStore(Val.getValue(1), dl, Val, FIN,
+ MachinePointerInfo(), false, false, 0);
+ MemOps.push_back(Store);
+ // Increment the address by four for the next argument to store
+ SDValue PtrOff = DAG.getConstant(PtrVT.getSizeInBits()/8, PtrVT);
+ FIN = DAG.getNode(ISD::ADD, dl, PtrOff.getValueType(), FIN, PtrOff);
+ }
+ }
+
+ if (!MemOps.empty())
+ Chain = DAG.getNode(ISD::TokenFactor, dl,
+ MVT::Other, &MemOps[0], MemOps.size());
+
+ return Chain;
+}
+
+SDValue
+PPCTargetLowering::LowerFormalArguments_Darwin(
SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg>
@@ -1959,7 +2251,6 @@
EVT PtrVT = DAG.getTargetLoweringInfo().getPointerTy();
bool isPPC64 = PtrVT == MVT::i64;
- bool isSVR4ABI = PPCSubTarget.isSVR4ABI();
// Potential tail calls could cause overwriting of argument stack slots.
bool isImmutable = !(getTargetMachine().Options.GuaranteedTailCallOpt &&
(CallConv == CallingConv::Fast));
@@ -2080,11 +2371,8 @@
// ObjSize is the true size, ArgSize rounded up to multiple of registers.
ObjSize = Flags.getByValSize();
ArgSize = ((ObjSize + PtrByteSize - 1)/PtrByteSize) * PtrByteSize;
- // FOR DARWIN: Objects of size 1 and 2 are right justified, everything
- // else is left justified. This means the memory address is adjusted
- // forwards.
- // FOR 64-BIT SVR4: All aggregates smaller than 8 bytes must be passed
- // right-justified.
+ // Objects of size 1 and 2 are right justified, everything else is
+ // left justified. This means the memory address is adjusted forwards.
if (ObjSize==1 || ObjSize==2) {
CurArgOffset = CurArgOffset + (4 - ObjSize);
}
@@ -2092,8 +2380,7 @@
int FI = MFI->CreateFixedObject(ObjSize, CurArgOffset, true);
SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
InVals.push_back(FIN);
- if (ObjSize==1 || ObjSize==2 ||
- (ObjSize==4 && isSVR4ABI)) {
+ if (ObjSize==1 || ObjSize==2) {
if (GPR_idx != Num_GPR_Regs) {
unsigned VReg;
if (isPPC64)
@@ -2128,16 +2415,7 @@
int FI = MFI->CreateFixedObject(PtrByteSize, ArgOffset, true);
SDValue FIN = DAG.getFrameIndex(FI, PtrVT);
SDValue Val = DAG.getCopyFromReg(Chain, dl, VReg, PtrVT);
- SDValue Shifted = Val;
-
- // For 64-bit SVR4, small structs come in right-adjusted.
- // Shift them left so the following logic works as expected.
- if (ObjSize < 8 && isSVR4ABI) {
- SDValue ShiftAmt = DAG.getConstant(64 - 8 * ObjSize, PtrVT);
- Shifted = DAG.getNode(ISD::SHL, dl, PtrVT, Val, ShiftAmt);
- }
-
- SDValue Store = DAG.getStore(Val.getValue(1), dl, Shifted, FIN,
+ SDValue Store = DAG.getStore(Val.getValue(1), dl, Val, FIN,
MachinePointerInfo(FuncArg, ArgOffset),
false, false, 0);
MemOps.push_back(Store);
Modified: llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h?rev=165336&r1=165335&r2=165336&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelLowering.h Fri Oct 5 16:27:08 2012
@@ -467,7 +467,13 @@
DebugLoc dl, SelectionDAG &DAG) const;
SDValue
- LowerFormalArguments_Darwin_Or_64SVR4(SDValue Chain,
+ LowerFormalArguments_Darwin(SDValue Chain,
+ CallingConv::ID CallConv, bool isVarArg,
+ const SmallVectorImpl<ISD::InputArg> &Ins,
+ DebugLoc dl, SelectionDAG &DAG,
+ SmallVectorImpl<SDValue> &InVals) const;
+ SDValue
+ LowerFormalArguments_64SVR4(SDValue Chain,
CallingConv::ID CallConv, bool isVarArg,
const SmallVectorImpl<ISD::InputArg> &Ins,
DebugLoc dl, SelectionDAG &DAG,
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