[MIR] Serialize MachineFrameInfo::isCalleeSavedInfoValid()

In case of functions without a stack frame no "stack" field is
serialized into MIR which leads to isCalleeSavedInfoValid being false
when reading a MIR file back in. To fix this we should serialize
MachineFrameInfo::isCalleeSavedInfoValid() into MIR.

Author: dtellenbach

llvm/include/llvm/CodeGen/MIRYamlMapping.h

@@ -640,6 +640,7 @@ struct MachineFrameInfo {
   bool HasVAStart = false;
   bool HasMustTailInVarArgFunc = false;
   bool HasTailCall = false;
+  bool IsCalleeSavedInfoValid = false;
   unsigned LocalFrameSize = 0;
   StringValue SavePoint;
   StringValue RestorePoint;
@@ -663,7 +664,8 @@ struct MachineFrameInfo {
            HasMustTailInVarArgFunc == Other.HasMustTailInVarArgFunc &&
            HasTailCall == Other.HasTailCall &&
            LocalFrameSize == Other.LocalFrameSize &&
-           SavePoint == Other.SavePoint && RestorePoint == Other.RestorePoint;
+           SavePoint == Other.SavePoint && RestorePoint == Other.RestorePoint &&
+           IsCalleeSavedInfoValid == Other.IsCalleeSavedInfoValid;
   }
 };
 
@@ -691,6 +693,8 @@ template <> struct MappingTraits<MachineFrameInfo> {
     YamlIO.mapOptional("hasMustTailInVarArgFunc", MFI.HasMustTailInVarArgFunc,
                        false);
     YamlIO.mapOptional("hasTailCall", MFI.HasTailCall, false);
+    YamlIO.mapOptional("isCalleeSavedInfoValid", MFI.IsCalleeSavedInfoValid,
+                       false);
     YamlIO.mapOptional("localFrameSize", MFI.LocalFrameSize, (unsigned)0);
     YamlIO.mapOptional("savePoint", MFI.SavePoint,
                        StringValue()); // Don't print it out when it's empty.

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

@@ -779,6 +779,7 @@ bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
   MFI.setHasVAStart(YamlMFI.HasVAStart);
   MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc);
   MFI.setHasTailCall(YamlMFI.HasTailCall);
+  MFI.setCalleeSavedInfoValid(YamlMFI.IsCalleeSavedInfoValid);
   MFI.setLocalFrameSize(YamlMFI.LocalFrameSize);
   if (!YamlMFI.SavePoint.Value.empty()) {
     MachineBasicBlock *MBB = nullptr;

llvm/lib/CodeGen/MIRPrinter.cpp

@@ -368,6 +368,7 @@ void MIRPrinter::convert(ModuleSlotTracker &MST,
   YamlMFI.HasVAStart = MFI.hasVAStart();
   YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
   YamlMFI.HasTailCall = MFI.hasTailCall();
+  YamlMFI.IsCalleeSavedInfoValid = MFI.isCalleeSavedInfoValid();
   YamlMFI.LocalFrameSize = MFI.getLocalFrameSize();
   if (MFI.getSavePoint()) {
     raw_string_ostream StrOS(YamlMFI.SavePoint.Value);

llvm/test/CodeGen/MIR/Generic/frame-info.mir

@@ -44,6 +44,7 @@ tracksRegLiveness: true
 # CHECK-NEXT: hasVAStart: false
 # CHECK-NEXT: hasMustTailInVarArgFunc: false
 # CHECK-NEXT: hasTailCall: false
+# CHECK-NEXT: isCalleeSavedInfoValid: false
 # CHECK-NEXT: localFrameSize: 0
 # CHECK-NEXT: savePoint:       ''
 # CHECK-NEXT: restorePoint:    ''