Make Win32 put the SRet address into EAX, fixes PR15556

llvm-svn: 178291

1 files changed, 10 insertions, 5 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 0eaab0f8185..bff5426f908 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -1666,10 +1666,11 @@ X86TargetLowering::LowerReturn(SDValue Chain,
 
   // The x86-64 ABIs require that for returning structs by value we copy
   // the sret argument into %rax/%eax (depending on ABI) for the return.
+  // 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 (Subtarget->is64Bit() &&
-      DAG.getMachineFunction().getFunction()->hasStructRetAttr()) {
+  if (DAG.getMachineFunction().getFunction()->hasStructRetAttr() &&
+      (Subtarget->is64Bit() || Subtarget->isTargetWindows())) {
     MachineFunction &MF = DAG.getMachineFunction();
     X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
     unsigned Reg = FuncInfo->getSRetReturnReg();
@@ -1677,12 +1678,14 @@ X86TargetLowering::LowerReturn(SDValue Chain,
            "SRetReturnReg should have been set in LowerFormalArguments().");
     SDValue Val = DAG.getCopyFromReg(Chain, dl, Reg, getPointerTy());
 
-    unsigned RetValReg = Subtarget->isTarget64BitILP32() ? X86::EAX : X86::RAX;
+    unsigned RetValReg
+        = (Subtarget->is64Bit() && !Subtarget->isTarget64BitILP32()) ?
+          X86::RAX : X86::EAX;
     Chain = DAG.getCopyToReg(Chain, dl, RetValReg, Val, Flag);
     Flag = Chain.getValue(1);
 
     // RAX/EAX now acts like a return value.
-    RetOps.push_back(DAG.getRegister(RetValReg, MVT::i64));
+    RetOps.push_back(DAG.getRegister(RetValReg, getPointerTy()));
   }
 
   RetOps[0] = Chain;  // Update chain.
@@ -2036,9 +2039,11 @@ X86TargetLowering::LowerFormalArguments(SDValue Chain,
 
   // The x86-64 ABIs require that for returning structs by value we copy
   // the sret argument into %rax/%eax (depending on ABI) for the return.
+  // Win32 requires us to put the sret argument to %eax as well.
   // Save the argument into a virtual register so that we can access it
   // from the return points.
-  if (Is64Bit && MF.getFunction()->hasStructRetAttr()) {
+  if (MF.getFunction()->hasStructRetAttr() &&
+      (Subtarget->is64Bit() || Subtarget->isTargetWindows())) {
     X86MachineFunctionInfo *FuncInfo = MF.getInfo<X86MachineFunctionInfo>();
     unsigned Reg = FuncInfo->getSRetReturnReg();
     if (!Reg) {