1 files changed, 380 insertions, 49 deletions

diff --git a/contrib/llvm/lib/Target/ARM/ARMCallLowering.cpp b/contrib/llvm/lib/Target/ARM/ARMCallLowering.cpp
index 52c95b6..051827a 100644
--- a/contrib/llvm/lib/Target/ARM/ARMCallLowering.cpp
+++ b/contrib/llvm/lib/Target/ARM/ARMCallLowering.cpp
@@ -17,8 +17,11 @@
 
 #include "ARMBaseInstrInfo.h"
 #include "ARMISelLowering.h"
+#include "ARMSubtarget.h"
 
+#include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
+#include "llvm/CodeGen/GlobalISel/Utils.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 
 using namespace llvm;
@@ -30,25 +33,61 @@ using namespace llvm;
 ARMCallLowering::ARMCallLowering(const ARMTargetLowering &TLI)
     : CallLowering(&TLI) {}
 
-static bool isSupportedType(const DataLayout DL, const ARMTargetLowering &TLI,
+static bool isSupportedType(const DataLayout &DL, const ARMTargetLowering &TLI,
                             Type *T) {
-  EVT VT = TLI.getValueType(DL, T);
-  if (!VT.isSimple() || !VT.isInteger() || VT.isVector())
+  if (T->isArrayTy())
+    return true;
+
+  if (T->isStructTy()) {
+    // For now we only allow homogeneous structs that we can manipulate with
+    // G_MERGE_VALUES and G_UNMERGE_VALUES
+    auto StructT = cast<StructType>(T);
+    for (unsigned i = 1, e = StructT->getNumElements(); i != e; ++i)
+      if (StructT->getElementType(i) != StructT->getElementType(0))
+        return false;
+    return true;
+  }
+
+  EVT VT = TLI.getValueType(DL, T, true);
+  if (!VT.isSimple() || VT.isVector() ||
+      !(VT.isInteger() || VT.isFloatingPoint()))
     return false;
 
   unsigned VTSize = VT.getSimpleVT().getSizeInBits();
-  return VTSize == 8 || VTSize == 16 || VTSize == 32;
+
+  if (VTSize == 64)
+    // FIXME: Support i64 too
+    return VT.isFloatingPoint();
+
+  return VTSize == 1 || VTSize == 8 || VTSize == 16 || VTSize == 32;
 }
 
 namespace {
-struct FuncReturnHandler : public CallLowering::ValueHandler {
-  FuncReturnHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
-                    MachineInstrBuilder &MIB)
-      : ValueHandler(MIRBuilder, MRI), MIB(MIB) {}
+/// Helper class for values going out through an ABI boundary (used for handling
+/// function return values and call parameters).
+struct OutgoingValueHandler : public CallLowering::ValueHandler {
+  OutgoingValueHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
+                       MachineInstrBuilder &MIB, CCAssignFn *AssignFn)
+      : ValueHandler(MIRBuilder, MRI, AssignFn), MIB(MIB), StackSize(0) {}
 
   unsigned getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
-    llvm_unreachable("Don't know how to get a stack address yet");
+    assert((Size == 1 || Size == 2 || Size == 4 || Size == 8) &&
+           "Unsupported size");
+
+    LLT p0 = LLT::pointer(0, 32);
+    LLT s32 = LLT::scalar(32);
+    unsigned SPReg = MRI.createGenericVirtualRegister(p0);
+    MIRBuilder.buildCopy(SPReg, ARM::SP);
+
+    unsigned OffsetReg = MRI.createGenericVirtualRegister(s32);
+    MIRBuilder.buildConstant(OffsetReg, Offset);
+
+    unsigned AddrReg = MRI.createGenericVirtualRegister(p0);
+    MIRBuilder.buildGEP(AddrReg, SPReg, OffsetReg);
+
+    MPO = MachinePointerInfo::getStack(MIRBuilder.getMF(), Offset);
+    return AddrReg;
   }
 
   void assignValueToReg(unsigned ValVReg, unsigned PhysReg,
@@ -56,26 +95,123 @@ struct FuncReturnHandler : public CallLowering::ValueHandler {
     assert(VA.isRegLoc() && "Value shouldn't be assigned to reg");
     assert(VA.getLocReg() == PhysReg && "Assigning to the wrong reg?");
 
-    assert(VA.getValVT().getSizeInBits() <= 32 && "Unsupported value size");
-    assert(VA.getLocVT().getSizeInBits() == 32 && "Unsupported location size");
-
-    assert(VA.getLocInfo() != CCValAssign::SExt &&
-           VA.getLocInfo() != CCValAssign::ZExt &&
-           "ABI extensions not supported yet");
+    assert(VA.getValVT().getSizeInBits() <= 64 && "Unsupported value size");
+    assert(VA.getLocVT().getSizeInBits() <= 64 && "Unsupported location size");
 
-    MIRBuilder.buildCopy(PhysReg, ValVReg);
+    unsigned ExtReg = extendRegister(ValVReg, VA);
+    MIRBuilder.buildCopy(PhysReg, ExtReg);
     MIB.addUse(PhysReg, RegState::Implicit);
   }
 
   void assignValueToAddress(unsigned ValVReg, unsigned Addr, uint64_t Size,
                             MachinePointerInfo &MPO, CCValAssign &VA) override {
-    llvm_unreachable("Don't know how to assign a value to an address yet");
+    assert((Size == 1 || Size == 2 || Size == 4 || Size == 8) &&
+           "Unsupported size");
+
+    unsigned ExtReg = extendRegister(ValVReg, VA);
+    auto MMO = MIRBuilder.getMF().getMachineMemOperand(
+        MPO, MachineMemOperand::MOStore, VA.getLocVT().getStoreSize(),
+        /* Alignment */ 0);
+    MIRBuilder.buildStore(ExtReg, Addr, *MMO);
+  }
+
+  unsigned assignCustomValue(const CallLowering::ArgInfo &Arg,
+                             ArrayRef<CCValAssign> VAs) override {
+    CCValAssign VA = VAs[0];
+    assert(VA.needsCustom() && "Value doesn't need custom handling");
+    assert(VA.getValVT() == MVT::f64 && "Unsupported type");
+
+    CCValAssign NextVA = VAs[1];
+    assert(NextVA.needsCustom() && "Value doesn't need custom handling");
+    assert(NextVA.getValVT() == MVT::f64 && "Unsupported type");
+
+    assert(VA.getValNo() == NextVA.getValNo() &&
+           "Values belong to different arguments");
+
+    assert(VA.isRegLoc() && "Value should be in reg");
+    assert(NextVA.isRegLoc() && "Value should be in reg");
+
+    unsigned NewRegs[] = {MRI.createGenericVirtualRegister(LLT::scalar(32)),
+                          MRI.createGenericVirtualRegister(LLT::scalar(32))};
+    MIRBuilder.buildUnmerge(NewRegs, Arg.Reg);
+
+    bool IsLittle = MIRBuilder.getMF().getSubtarget<ARMSubtarget>().isLittle();
+    if (!IsLittle)
+      std::swap(NewRegs[0], NewRegs[1]);
+
+    assignValueToReg(NewRegs[0], VA.getLocReg(), VA);
+    assignValueToReg(NewRegs[1], NextVA.getLocReg(), NextVA);
+
+    return 1;
+  }
+
+  bool assignArg(unsigned ValNo, MVT ValVT, MVT LocVT,
+                 CCValAssign::LocInfo LocInfo,
+                 const CallLowering::ArgInfo &Info, CCState &State) override {
+    if (AssignFn(ValNo, ValVT, LocVT, LocInfo, Info.Flags, State))
+      return true;
+
+    StackSize =
+        std::max(StackSize, static_cast<uint64_t>(State.getNextStackOffset()));
+    return false;
   }
 
   MachineInstrBuilder &MIB;
+  uint64_t StackSize;
 };
 } // End anonymous namespace.
 
+void ARMCallLowering::splitToValueTypes(
+    const ArgInfo &OrigArg, SmallVectorImpl<ArgInfo> &SplitArgs,
+    MachineFunction &MF, const SplitArgTy &PerformArgSplit) const {
+  const ARMTargetLowering &TLI = *getTLI<ARMTargetLowering>();
+  LLVMContext &Ctx = OrigArg.Ty->getContext();
+  const DataLayout &DL = MF.getDataLayout();
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  const Function *F = MF.getFunction();
+
+  SmallVector<EVT, 4> SplitVTs;
+  SmallVector<uint64_t, 4> Offsets;
+  ComputeValueVTs(TLI, DL, OrigArg.Ty, SplitVTs, &Offsets, 0);
+
+  if (SplitVTs.size() == 1) {
+    // Even if there is no splitting to do, we still want to replace the
+    // original type (e.g. pointer type -> integer).
+    auto Flags = OrigArg.Flags;
+    unsigned OriginalAlignment = DL.getABITypeAlignment(OrigArg.Ty);
+    Flags.setOrigAlign(OriginalAlignment);
+    SplitArgs.emplace_back(OrigArg.Reg, SplitVTs[0].getTypeForEVT(Ctx), Flags,
+                           OrigArg.IsFixed);
+    return;
+  }
+
+  unsigned FirstRegIdx = SplitArgs.size();
+  for (unsigned i = 0, e = SplitVTs.size(); i != e; ++i) {
+    EVT SplitVT = SplitVTs[i];
+    Type *SplitTy = SplitVT.getTypeForEVT(Ctx);
+    auto Flags = OrigArg.Flags;
+
+    unsigned OriginalAlignment = DL.getABITypeAlignment(SplitTy);
+    Flags.setOrigAlign(OriginalAlignment);
+
+    bool NeedsConsecutiveRegisters =
+        TLI.functionArgumentNeedsConsecutiveRegisters(
+            SplitTy, F->getCallingConv(), F->isVarArg());
+    if (NeedsConsecutiveRegisters) {
+      Flags.setInConsecutiveRegs();
+      if (i == e - 1)
+        Flags.setInConsecutiveRegsLast();
+    }
+
+    SplitArgs.push_back(
+        ArgInfo{MRI.createGenericVirtualRegister(getLLTForType(*SplitTy, DL)),
+                SplitTy, Flags, OrigArg.IsFixed});
+  }
+
+  for (unsigned i = 0; i < Offsets.size(); ++i)
+    PerformArgSplit(SplitArgs[FirstRegIdx + i].Reg, Offsets[i] * 8);
+}
+
 /// Lower the return value for the already existing \p Ret. This assumes that
 /// \p MIRBuilder's insertion point is correct.
 bool ARMCallLowering::lowerReturnVal(MachineIRBuilder &MIRBuilder,
@@ -93,21 +229,29 @@ bool ARMCallLowering::lowerReturnVal(MachineIRBuilder &MIRBuilder,
   if (!isSupportedType(DL, TLI, Val->getType()))
     return false;
 
+  SmallVector<ArgInfo, 4> SplitVTs;
+  SmallVector<unsigned, 4> Regs;
+  ArgInfo RetInfo(VReg, Val->getType());
+  setArgFlags(RetInfo, AttributeList::ReturnIndex, DL, F);
+  splitToValueTypes(RetInfo, SplitVTs, MF, [&](unsigned Reg, uint64_t Offset) {
+    Regs.push_back(Reg);
+  });
+
+  if (Regs.size() > 1)
+    MIRBuilder.buildUnmerge(Regs, VReg);
+
   CCAssignFn *AssignFn =
       TLI.CCAssignFnForReturn(F.getCallingConv(), F.isVarArg());
 
-  ArgInfo RetInfo(VReg, Val->getType());
-  setArgFlags(RetInfo, AttributeSet::ReturnIndex, DL, F);
-
-  FuncReturnHandler RetHandler(MIRBuilder, MF.getRegInfo(), Ret);
-  return handleAssignments(MIRBuilder, AssignFn, RetInfo, RetHandler);
+  OutgoingValueHandler RetHandler(MIRBuilder, MF.getRegInfo(), Ret, AssignFn);
+  return handleAssignments(MIRBuilder, SplitVTs, RetHandler);
 }
 
 bool ARMCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
                                   const Value *Val, unsigned VReg) const {
   assert(!Val == !VReg && "Return value without a vreg");
 
-  auto Ret = AddDefaultPred(MIRBuilder.buildInstrNoInsert(ARM::BX_RET));
+  auto Ret = MIRBuilder.buildInstrNoInsert(ARM::BX_RET).add(predOps(ARMCC::AL));
 
   if (!lowerReturnVal(MIRBuilder, Val, VReg, Ret))
     return false;
@@ -117,13 +261,17 @@ bool ARMCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
 }
 
 namespace {
-struct FormalArgHandler : public CallLowering::ValueHandler {
-  FormalArgHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI)
-      : ValueHandler(MIRBuilder, MRI) {}
+/// Helper class for values coming in through an ABI boundary (used for handling
+/// formal arguments and call return values).
+struct IncomingValueHandler : public CallLowering::ValueHandler {
+  IncomingValueHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
+                       CCAssignFn AssignFn)
+      : ValueHandler(MIRBuilder, MRI, AssignFn) {}
 
   unsigned getStackAddress(uint64_t Size, int64_t Offset,
                            MachinePointerInfo &MPO) override {
-    assert(Size == 4 && "Unsupported size");
+    assert((Size == 1 || Size == 2 || Size == 4 || Size == 8) &&
+           "Unsupported size");
 
     auto &MFI = MIRBuilder.getMF().getFrameInfo();
 
@@ -139,11 +287,30 @@ struct FormalArgHandler : public CallLowering::ValueHandler {
 
   void assignValueToAddress(unsigned ValVReg, unsigned Addr, uint64_t Size,
                             MachinePointerInfo &MPO, CCValAssign &VA) override {
-    assert(Size == 4 && "Unsupported size");
+    assert((Size == 1 || Size == 2 || Size == 4 || Size == 8) &&
+           "Unsupported size");
+
+    if (VA.getLocInfo() == CCValAssign::SExt ||
+        VA.getLocInfo() == CCValAssign::ZExt) {
+      // If the value is zero- or sign-extended, its size becomes 4 bytes, so
+      // that's what we should load.
+      Size = 4;
+      assert(MRI.getType(ValVReg).isScalar() && "Only scalars supported atm");
+
+      auto LoadVReg = MRI.createGenericVirtualRegister(LLT::scalar(32));
+      buildLoad(LoadVReg, Addr, Size, /* Alignment */ 0, MPO);
+      MIRBuilder.buildTrunc(ValVReg, LoadVReg);
+    } else {
+      // If the value is not extended, a simple load will suffice.
+      buildLoad(ValVReg, Addr, Size, /* Alignment */ 0, MPO);
+    }
+  }
 
+  void buildLoad(unsigned Val, unsigned Addr, uint64_t Size, unsigned Alignment,
+                 MachinePointerInfo &MPO) {
     auto MMO = MIRBuilder.getMF().getMachineMemOperand(
-        MPO, MachineMemOperand::MOLoad, Size, /* Alignment */ 0);
-    MIRBuilder.buildLoad(ValVReg, Addr, *MMO);
+        MPO, MachineMemOperand::MOLoad, Size, Alignment);
+    MIRBuilder.buildLoad(Val, Addr, *MMO);
   }
 
   void assignValueToReg(unsigned ValVReg, unsigned PhysReg,
@@ -151,12 +318,60 @@ struct FormalArgHandler : public CallLowering::ValueHandler {
     assert(VA.isRegLoc() && "Value shouldn't be assigned to reg");
     assert(VA.getLocReg() == PhysReg && "Assigning to the wrong reg?");
 
-    assert(VA.getValVT().getSizeInBits() <= 32 && "Unsupported value size");
-    assert(VA.getLocVT().getSizeInBits() == 32 && "Unsupported location size");
+    assert(VA.getValVT().getSizeInBits() <= 64 && "Unsupported value size");
+    assert(VA.getLocVT().getSizeInBits() <= 64 && "Unsupported location size");
 
-    MIRBuilder.getMBB().addLiveIn(PhysReg);
+    // The necessary extensions are handled on the other side of the ABI
+    // boundary.
+    markPhysRegUsed(PhysReg);
     MIRBuilder.buildCopy(ValVReg, PhysReg);
   }
+
+  unsigned assignCustomValue(const ARMCallLowering::ArgInfo &Arg,
+                             ArrayRef<CCValAssign> VAs) override {
+    CCValAssign VA = VAs[0];
+    assert(VA.needsCustom() && "Value doesn't need custom handling");
+    assert(VA.getValVT() == MVT::f64 && "Unsupported type");
+
+    CCValAssign NextVA = VAs[1];
+    assert(NextVA.needsCustom() && "Value doesn't need custom handling");
+    assert(NextVA.getValVT() == MVT::f64 && "Unsupported type");
+
+    assert(VA.getValNo() == NextVA.getValNo() &&
+           "Values belong to different arguments");
+
+    assert(VA.isRegLoc() && "Value should be in reg");
+    assert(NextVA.isRegLoc() && "Value should be in reg");
+
+    unsigned NewRegs[] = {MRI.createGenericVirtualRegister(LLT::scalar(32)),
+                          MRI.createGenericVirtualRegister(LLT::scalar(32))};
+
+    assignValueToReg(NewRegs[0], VA.getLocReg(), VA);
+    assignValueToReg(NewRegs[1], NextVA.getLocReg(), NextVA);
+
+    bool IsLittle = MIRBuilder.getMF().getSubtarget<ARMSubtarget>().isLittle();
+    if (!IsLittle)
+      std::swap(NewRegs[0], NewRegs[1]);
+
+    MIRBuilder.buildMerge(Arg.Reg, NewRegs);
+
+    return 1;
+  }
+
+  /// Marking a physical register as used is different between formal
+  /// parameters, where it's a basic block live-in, and call returns, where it's
+  /// an implicit-def of the call instruction.
+  virtual void markPhysRegUsed(unsigned PhysReg) = 0;
+};
+
+struct FormalArgHandler : public IncomingValueHandler {
+  FormalArgHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
+                   CCAssignFn AssignFn)
+      : IncomingValueHandler(MIRBuilder, MRI, AssignFn) {}
+
+  void markPhysRegUsed(unsigned PhysReg) override {
+    MIRBuilder.getMBB().addLiveIn(PhysReg);
+  }
 };
 } // End anonymous namespace
 
@@ -170,34 +385,150 @@ bool ARMCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
   if (F.isVarArg())
     return false;
 
-  auto DL = MIRBuilder.getMF().getDataLayout();
+  auto &MF = MIRBuilder.getMF();
+  auto &MBB = MIRBuilder.getMBB();
+  auto DL = MF.getDataLayout();
   auto &TLI = *getTLI<ARMTargetLowering>();
 
-  auto &Args = F.getArgumentList();
-  unsigned ArgIdx = 0;
-  for (auto &Arg : Args) {
-    ArgIdx++;
-    if (!isSupportedType(DL, TLI, Arg.getType()))
-      return false;
+  auto Subtarget = TLI.getSubtarget();
+
+  if (Subtarget->isThumb())
+    return false;
 
-    // FIXME: This check as well as ArgIdx are going away as soon as we support
-    // loading values < 32 bits.
-    if (ArgIdx > 4 && Arg.getType()->getIntegerBitWidth() != 32)
+  for (auto &Arg : F.args())
+    if (!isSupportedType(DL, TLI, Arg.getType()))
       return false;
-  }
 
   CCAssignFn *AssignFn =
       TLI.CCAssignFnForCall(F.getCallingConv(), F.isVarArg());
 
+  FormalArgHandler ArgHandler(MIRBuilder, MIRBuilder.getMF().getRegInfo(),
+                              AssignFn);
+
   SmallVector<ArgInfo, 8> ArgInfos;
+  SmallVector<unsigned, 4> SplitRegs;
   unsigned Idx = 0;
-  for (auto &Arg : Args) {
+  for (auto &Arg : F.args()) {
     ArgInfo AInfo(VRegs[Idx], Arg.getType());
-    setArgFlags(AInfo, Idx + 1, DL, F);
-    ArgInfos.push_back(AInfo);
+    setArgFlags(AInfo, Idx + AttributeList::FirstArgIndex, DL, F);
+
+    SplitRegs.clear();
+
+    splitToValueTypes(AInfo, ArgInfos, MF, [&](unsigned Reg, uint64_t Offset) {
+      SplitRegs.push_back(Reg);
+    });
+
+    if (!SplitRegs.empty())
+      MIRBuilder.buildMerge(VRegs[Idx], SplitRegs);
+
     Idx++;
   }
 
-  FormalArgHandler ArgHandler(MIRBuilder, MIRBuilder.getMF().getRegInfo());
-  return handleAssignments(MIRBuilder, AssignFn, ArgInfos, ArgHandler);
+  if (!MBB.empty())
+    MIRBuilder.setInstr(*MBB.begin());
+
+  return handleAssignments(MIRBuilder, ArgInfos, ArgHandler);
+}
+
+namespace {
+struct CallReturnHandler : public IncomingValueHandler {
+  CallReturnHandler(MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI,
+                    MachineInstrBuilder MIB, CCAssignFn *AssignFn)
+      : IncomingValueHandler(MIRBuilder, MRI, AssignFn), MIB(MIB) {}
+
+  void markPhysRegUsed(unsigned PhysReg) override {
+    MIB.addDef(PhysReg, RegState::Implicit);
+  }
+
+  MachineInstrBuilder MIB;
+};
+} // End anonymous namespace.
+
+bool ARMCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
+                                CallingConv::ID CallConv,
+                                const MachineOperand &Callee,
+                                const ArgInfo &OrigRet,
+                                ArrayRef<ArgInfo> OrigArgs) const {
+  MachineFunction &MF = MIRBuilder.getMF();
+  const auto &TLI = *getTLI<ARMTargetLowering>();
+  const auto &DL = MF.getDataLayout();
+  const auto &STI = MF.getSubtarget();
+  const TargetRegisterInfo *TRI = STI.getRegisterInfo();
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+
+  if (MF.getSubtarget<ARMSubtarget>().genLongCalls())
+    return false;
+
+  auto CallSeqStart = MIRBuilder.buildInstr(ARM::ADJCALLSTACKDOWN);
+
+  // Create the call instruction so we can add the implicit uses of arg
+  // registers, but don't insert it yet.
+  auto MIB = MIRBuilder.buildInstrNoInsert(ARM::BLX).add(Callee).addRegMask(
+      TRI->getCallPreservedMask(MF, CallConv));
+  if (Callee.isReg()) {
+    auto CalleeReg = Callee.getReg();
+    if (CalleeReg && !TRI->isPhysicalRegister(CalleeReg))
+      MIB->getOperand(0).setReg(constrainOperandRegClass(
+          MF, *TRI, MRI, *STI.getInstrInfo(), *STI.getRegBankInfo(),
+          *MIB.getInstr(), MIB->getDesc(), CalleeReg, 0));
+  }
+
+  SmallVector<ArgInfo, 8> ArgInfos;
+  for (auto Arg : OrigArgs) {
+    if (!isSupportedType(DL, TLI, Arg.Ty))
+      return false;
+
+    if (!Arg.IsFixed)
+      return false;
+
+    SmallVector<unsigned, 8> Regs;
+    splitToValueTypes(Arg, ArgInfos, MF, [&](unsigned Reg, uint64_t Offset) {
+      Regs.push_back(Reg);
+    });
+
+    if (Regs.size() > 1)
+      MIRBuilder.buildUnmerge(Regs, Arg.Reg);
+  }
+
+  auto ArgAssignFn = TLI.CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
+  OutgoingValueHandler ArgHandler(MIRBuilder, MRI, MIB, ArgAssignFn);
+  if (!handleAssignments(MIRBuilder, ArgInfos, ArgHandler))
+    return false;
+
+  // Now we can add the actual call instruction to the correct basic block.
+  MIRBuilder.insertInstr(MIB);
+
+  if (!OrigRet.Ty->isVoidTy()) {
+    if (!isSupportedType(DL, TLI, OrigRet.Ty))
+      return false;
+
+    ArgInfos.clear();
+    SmallVector<unsigned, 8> SplitRegs;
+    splitToValueTypes(OrigRet, ArgInfos, MF,
+                      [&](unsigned Reg, uint64_t Offset) {
+                        SplitRegs.push_back(Reg);
+                      });
+
+    auto RetAssignFn = TLI.CCAssignFnForReturn(CallConv, /*IsVarArg=*/false);
+    CallReturnHandler RetHandler(MIRBuilder, MRI, MIB, RetAssignFn);
+    if (!handleAssignments(MIRBuilder, ArgInfos, RetHandler))
+      return false;
+
+    if (!SplitRegs.empty()) {
+      // We have split the value and allocated each individual piece, now build
+      // it up again.
+      MIRBuilder.buildMerge(OrigRet.Reg, SplitRegs);
+    }
+  }
+
+  // We now know the size of the stack - update the ADJCALLSTACKDOWN
+  // accordingly.
+  CallSeqStart.addImm(ArgHandler.StackSize).addImm(0).add(predOps(ARMCC::AL));
+
+  MIRBuilder.buildInstr(ARM::ADJCALLSTACKUP)
+      .addImm(ArgHandler.StackSize)
+      .addImm(0)
+      .add(predOps(ARMCC::AL));
+
+  return true;
 }