// Win32 requires us to put the sret argument to %eax as well.
// We saved the argument into a virtual register in the entry block,
// so now we copy the value out and into %rax/%eax.
- if (DAG.getMachineFunction().getFunction()->hasStructRetAttr() &&
- (Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC())) {
- MachineFunction &MF = DAG.getMachineFunction();
- X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
- unsigned Reg = FuncInfo->getSRetReturnReg();
- assert(Reg &&
- "SRetReturnReg should have been set in LowerFormalArguments().");
- SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
+ //
+ // Checking Function.hasStructRetAttr() here is insufficient because the IR
+ // may not have an explicit sret argument. If FuncInfo.CanLowerReturn is
+ // false, then an sret argument may be implicitly inserted in the SelDAG. In
+ // either case FuncInfo->setSRetReturnReg() will have been called.
+ if (unsigned SRetReg = FuncInfo->getSRetReturnReg()) {
+ assert((Subtarget->is64Bit() || Subtarget->isTargetKnownWindowsMSVC()) &&
+ "No need for an sret register");
+ SDValue Val = DAG.getCopyFromReg(Chain, dl, SRetReg, getPointerTy());
unsigned RetValReg
= (Subtarget->is64Bit() && !Subtarget->isTarget64BitILP32()) ?