Index: lib/Target/X86/X86RegisterInfo.cpp
===================================================================
--- lib/Target/X86/X86RegisterInfo.cpp
+++ lib/Target/X86/X86RegisterInfo.cpp
@@ -220,6 +220,7 @@
 X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   bool HasAVX = Subtarget.hasAVX();
   bool HasAVX512 = Subtarget.hasAVX512();
+  bool CallsEHReturn = MF->getMMI().callsEHReturn();
 
   assert(MF && "MachineFunction required");
   switch (MF->getFunction()->getCallingConv()) {
@@ -253,11 +254,16 @@
     if (Is64Bit)
       return CSR_64_MostRegs_SaveList;
     break;
+  case CallingConv::X86_64_Win64:
+    return CSR_Win64_SaveList;
+  case CallingConv::X86_64_SysV:
+    if (CallsEHReturn)
+      return CSR_64EHRet_SaveList;
+    return CSR_64_SaveList;
   default:
     break;
   }
 
-  bool CallsEHReturn = MF->getMMI().callsEHReturn();
   if (Is64Bit) {
     if (IsWin64)
       return CSR_Win64_SaveList;
@@ -308,6 +314,10 @@
     break;
   default:
     break;
+  case CallingConv::X86_64_Win64:
+    return CSR_Win64_RegMask;
+  case CallingConv::X86_64_SysV:
+    return CSR_64_RegMask;
   }
 
   // Unlike getCalleeSavedRegs(), we don't have MMI so we can't check
Index: test/CodeGen/X86/win64_nonvol.ll
===================================================================
--- /dev/null
+++ test/CodeGen/X86/win64_nonvol.ll
@@ -0,0 +1,31 @@
+; RUN: llc < %s -mtriple=x86_64-pc-win32 | FileCheck %s
+; RUN: llc < %s -mtriple=x86_64-pc-linux | FileCheck %s
+
+; Check that, if a Win64 ABI function calls a SysV ABI function, all the
+; Win64 nonvolatile registers get saved.
+
+; CHECK-LABEL: foo:
+define x86_64_sysvcc void @foo(i32 %a, i32 %b) {
+; CHECK: ret
+  ret void
+}
+
+; CHECK-LABEL: bar:
+define x86_64_win64cc void @bar(i32 %a, i32 %b) {
+; CHECK-DAG: pushq %rdi
+; CHECK-DAG: pushq %rsi
+; CHECK-DAG: movaps %xmm6,
+; CHECK-DAG: movaps %xmm7,
+; CHECK-DAG: movaps %xmm8,
+; CHECK-DAG: movaps %xmm9,
+; CHECK-DAG: movaps %xmm10,
+; CHECK-DAG: movaps %xmm11,
+; CHECK-DAG: movaps %xmm12,
+; CHECK-DAG: movaps %xmm13,
+; CHECK-DAG: movaps %xmm14,
+; CHECK-DAG: movaps %xmm15,
+; CHECK: callq foo
+; CHECK: ret
+  call x86_64_sysvcc void @foo(i32 %a, i32 %b)
+  ret void
+}