From d51be017f089137d356219d08f563d7961c664ce Mon Sep 17 00:00:00 2001
From: Charles Davis <cdavis5x@gmail.com>
Date: Fri, 27 Feb 2015 00:57:01 +0000
Subject: [PATCH] Target/X86: Save Win64 non-volatile registers in a Win64 ABI
 function.

Summary:
This change causes us to actually save non-volatile registers in a Win64
ABI function that calls a System V ABI function, and vice-versa.

Reviewers: rnk

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D7919

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230714 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/X86/X86RegisterInfo.cpp | 12 +++++++++++-
 test/CodeGen/X86/win64_nonvol.ll   | 28 ++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 test/CodeGen/X86/win64_nonvol.ll

diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index cab7ce801db..f1fd5470c88 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -220,6 +220,7 @@ const MCPhysReg *
 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 @@ X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
     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 @@ X86RegisterInfo::getCallPreservedMask(CallingConv::ID CC) const {
     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
diff --git a/test/CodeGen/X86/win64_nonvol.ll b/test/CodeGen/X86/win64_nonvol.ll
new file mode 100644
index 00000000000..8e5f6cec1ab
--- /dev/null
+++ b/test/CodeGen/X86/win64_nonvol.ll
@@ -0,0 +1,28 @@
+; 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: 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
+}
+
+declare x86_64_sysvcc void @foo(i32 %a, i32 %b)
+
-- 
2.34.1