MIR Serialization: Serialize the local offsets for the stack objects.

llvm-svn: 245249

llvm/include/llvm/CodeGen/MIRYamlMapping.h

@@ -184,8 +184,7 @@ template <> struct MappingTraits<MachineFunctionLiveIn> {
 /// determined by the object's type and frame information flags.
 /// Dead stack objects aren't serialized.
 ///
-/// TODO: Determine isPreallocated flag by mapping between objects and local
-/// objects (Serialize local objects).
+/// The 'isPreallocated' flag is determined by the local offset.
 struct MachineStackObject {
   enum ObjectType { DefaultType, SpillSlot, VariableSized };
   UnsignedValue ID;
@@ -196,6 +195,7 @@ struct MachineStackObject {
   uint64_t Size = 0;
   unsigned Alignment = 0;
   StringValue CalleeSavedRegister;
+  Optional<int64_t> LocalOffset;
 };
 
 template <> struct ScalarEnumerationTraits<MachineStackObject::ObjectType> {
@@ -220,6 +220,7 @@ template <> struct MappingTraits<MachineStackObject> {
     YamlIO.mapOptional("alignment", Object.Alignment);
     YamlIO.mapOptional("callee-saved-register", Object.CalleeSavedRegister,
                        StringValue()); // Don't print it out when it's empty.
+    YamlIO.mapOptional("local-offset", Object.LocalOffset);
   }
 
   static const bool flow = true;
@@ -338,7 +339,6 @@ struct MachineFrameInfo {
   bool HasCalls = false;
   // TODO: Serialize StackProtectorIdx and FunctionContextIdx
   unsigned MaxCallFrameSize = 0;
-  // TODO: Serialize local frame objects.
   bool HasOpaqueSPAdjustment = false;
   bool HasVAStart = false;
   bool HasMustTailInVarArgFunc = false;

llvm/lib/CodeGen/MIRParser/MIRParser.cpp

@@ -487,6 +487,8 @@ bool MIRParserImpl::initializeFrameInfo(MachineFunction &MF,
     if (parseCalleeSavedRegister(MF, PFS, CSIInfo, Object.CalleeSavedRegister,
                                  ObjectIdx))
       return true;
+    if (Object.LocalOffset)
+      MFI.mapLocalFrameObject(ObjectIdx, Object.LocalOffset.getValue());
   }
   MFI.setCalleeSavedInfo(CSIInfo);
   if (!CSIInfo.empty())

llvm/lib/CodeGen/MIRPrinter.cpp

@@ -324,6 +324,15 @@ void MIRPrinter::convertStackObjects(yaml::MachineFunction &MF,
     else
       MF.StackObjects[StackObject.ID].CalleeSavedRegister = Reg;
   }
+  for (unsigned I = 0, E = MFI.getLocalFrameObjectCount(); I < E; ++I) {
+    auto LocalObject = MFI.getLocalFrameObjectMap(I);
+    auto StackObjectInfo = StackObjectOperandMapping.find(LocalObject.first);
+    assert(StackObjectInfo != StackObjectOperandMapping.end() &&
+           "Invalid stack object index");
+    const FrameIndexOperand &StackObject = StackObjectInfo->second;
+    assert(!StackObject.IsFixed && "Expected a locally mapped stack object");
+    MF.StackObjects[StackObject.ID].LocalOffset = LocalObject.second;
+  }
 }
 
 void MIRPrinter::convert(yaml::MachineFunction &MF,

llvm/test/CodeGen/MIR/AArch64/stack-object-local-offset.mir

@@ -0,0 +1,41 @@
+# RUN: llc -mtriple=aarch64-none-linux-gnu -start-after machine-sink -stop-after machine-sink -o /dev/null %s | FileCheck %s
+
+--- |
+  @var = global i64 0
+  @local_addr = global i64* null
+
+  define void @stack_local() {
+  entry:
+    %local_var = alloca i64
+    %val = load i64, i64* @var
+    store i64 %val, i64* %local_var
+    store i64* %local_var, i64** @local_addr
+    ret void
+  }
+...
+---
+name:            stack_local
+isSSA:           true
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gpr64common }
+  - { id: 1, class: gpr64 }
+  - { id: 2, class: gpr64common }
+  - { id: 3, class: gpr64common }
+frameInfo:
+  maxAlignment:    8
+# CHECK-LABEL: stack_local
+# CHECK: stack:
+# CHECK_NEXT: { id:0, name:local_var, offset:0, size:8, alignment:8, local-offset: -8 }
+stack:
+  - { id: 0,name: local_var,offset: 0,size: 8,alignment: 8, local-offset: -8 }
+body: |
+  bb.0.entry:
+    %0 = ADRP @var
+    %1 = LDRXui killed %0, @var :: (load 8 from %ir.var)
+    STRXui killed %1, %stack.0.local_var, 0 :: (store 8 into %ir.local_var)
+    %2 = ADRP @local_addr
+    %3 = ADDXri %stack.0.local_var, 0, 0
+    STRXui killed %3, killed %2, @local_addr :: (store 8 into %ir.local_addr)
+    RET_ReallyLR
+...