X86: remove R12 from CSR on Windows x64 SwiftCC

R12 is used for the SwiftError parameter.  It is no longer a CSR as it
is used for transfer the SwiftError, and the caller must preserve it if
they need to.

llvm-svn: 314165

1 files changed, 19 insertions, 20 deletions

diff --git a/llvm/lib/Target/X86/X86RegisterInfo.cpp b/llvm/lib/Target/X86/X86RegisterInfo.cpp
index 343da2573b5..1f49650340e 100644
--- a/llvm/lib/Target/X86/X86RegisterInfo.cpp
+++ b/llvm/lib/Target/X86/X86RegisterInfo.cpp
@@ -271,12 +271,13 @@ X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   assert(MF && "MachineFunction required");
 
   const X86Subtarget &Subtarget = MF->getSubtarget<X86Subtarget>();
+  const Function *F = MF->getFunction();
   bool HasSSE = Subtarget.hasSSE1();
   bool HasAVX = Subtarget.hasAVX();
   bool HasAVX512 = Subtarget.hasAVX512();
   bool CallsEHReturn = MF->callsEHReturn();
 
-  CallingConv::ID CC = MF->getFunction()->getCallingConv();
+  CallingConv::ID CC = F->getCallingConv();
 
   // If attribute NoCallerSavedRegisters exists then we set X86_INTR calling
   // convention because it has the CSR list.
@@ -365,22 +366,20 @@ X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
   }
 
   if (Is64Bit) {
-    if (IsWin64) {
-      if (!HasSSE)
-        return CSR_Win64_NoSSE_SaveList;
-      return CSR_Win64_SaveList;
-    }
+    bool IsSwiftCC = Subtarget.getTargetLowering()->supportSwiftError() &&
+                     F->getAttributes().hasAttrSomewhere(Attribute::SwiftError);
+    if (IsSwiftCC)
+      return IsWin64 ? CSR_Win64_SwiftError_SaveList
+                     : CSR_64_SwiftError_SaveList;
+
+    if (IsWin64)
+      return HasSSE ? CSR_Win64_SaveList : CSR_Win64_NoSSE_SaveList;
     if (CallsEHReturn)
       return CSR_64EHRet_SaveList;
-    if (Subtarget.getTargetLowering()->supportSwiftError() &&
-        MF->getFunction()->getAttributes().hasAttrSomewhere(
-            Attribute::SwiftError))
-      return CSR_64_SwiftError_SaveList;
     return CSR_64_SaveList;
   }
-  if (CallsEHReturn)
-    return CSR_32EHRet_SaveList;
-  return CSR_32_SaveList;
+
+  return CallsEHReturn ? CSR_32EHRet_SaveList : CSR_32_SaveList;
 }
 
 const MCPhysReg *X86RegisterInfo::getCalleeSavedRegsViaCopy(
@@ -479,14 +478,14 @@ X86RegisterInfo::getCallPreservedMask(const MachineFunction &MF,
   // Unlike getCalleeSavedRegs(), we don't have MMI so we can't check
   // callsEHReturn().
   if (Is64Bit) {
-    if (IsWin64)
-      return CSR_Win64_RegMask;
-    if (Subtarget.getTargetLowering()->supportSwiftError() &&
-        MF.getFunction()->getAttributes().hasAttrSomewhere(
-            Attribute::SwiftError))
-      return CSR_64_SwiftError_RegMask;
-    return CSR_64_RegMask;
+    const Function *F = MF.getFunction();
+    bool IsSwiftCC = Subtarget.getTargetLowering()->supportSwiftError() &&
+                     F->getAttributes().hasAttrSomewhere(Attribute::SwiftError);
+    if (IsSwiftCC)
+      return IsWin64 ? CSR_Win64_SwiftError_RegMask : CSR_64_SwiftError_RegMask;
+    return IsWin64 ? CSR_Win64_RegMask : CSR_64_RegMask;
   }
+
   return CSR_32_RegMask;
 }