MIR Serialization: Serialize simple MachineRegisterInfo attributes.

[arphaman]

Summary

This patch serializes the 3 scalar bool attributes from the MachineRegisterInfo class. - isSSA, tracksRegLiveness, tracksSubRegLiveness. I decided to place them into the machine function YAML mapping as they fit rather well into the function's mapping.

include/llvm/CodeGen/MIRYamlMapping.h

 namespace llvm {
 namespace yaml {
 
 struct MachineFunction {
   StringRef Name;
   unsigned Alignment = 0;
   bool ExposesReturnsTwice = false;
   bool HasInlineAsm = false;
+  // Register information
+  bool IsSSA = false;
+  bool TracksRegLiveness = false;
+  bool TracksSubRegLiveness = false;
+  // TODO: Serialize virtual register definitions.
+  // TODO: Serialize the various register masks.
+  // TODO: Serialize live in registers.
 
   std::vector<MachineBasicBlock> BasicBlocks;
 };
 
 template <> struct MappingTraits<MachineFunction> {
   static void mapping(IO &YamlIO, MachineFunction &MF) {
     YamlIO.mapRequired("name", MF.Name);
     YamlIO.mapOptional("alignment", MF.Alignment);
     YamlIO.mapOptional("exposesReturnsTwice", MF.ExposesReturnsTwice);
     YamlIO.mapOptional("hasInlineAsm", MF.HasInlineAsm);
+    YamlIO.mapOptional("isSSA", MF.IsSSA);
+    YamlIO.mapOptional("tracksRegLiveness", MF.TracksRegLiveness);
+    YamlIO.mapOptional("tracksSubRegLiveness", MF.TracksSubRegLiveness);
+
     YamlIO.mapOptional("body", MF.BasicBlocks);
   }
 };
 
 } // end namespace yaml
 } // end namespace llvm
 
 #endif

lib/CodeGen/MIRParser/MIRParser.cpp

 
 #include "llvm/CodeGen/MIRParser/MIRParser.h"
 #include "MIParser.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/AsmParser/Parser.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/MIRYamlMapping.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/ValueSymbolTable.h"
 #include "llvm/Support/LineIterator.h"
public:
   bool initializeMachineFunction(MachineFunction &MF);
 
   /// Initialize the machine basic block using it's YAML representation.
   ///
   /// Return true if an error occurred.
   bool initializeMachineBasicBlock(MachineFunction &MF, MachineBasicBlock &MBB,
                                    const yaml::MachineBasicBlock &YamlMBB);
 
+  bool initializeRegisterInfo(MachineRegisterInfo &RegInfo,
+                              const yaml::MachineFunction &YamlMF);
+
 private:
   /// Return a MIR diagnostic converted from an LLVM assembly diagnostic.
   SMDiagnostic diagFromLLVMAssemblyDiag(const SMDiagnostic &Error,
                                         SMRange SourceRange);
 
   /// Create an empty function with the given name.
   void createDummyFunction(StringRef Name, Module &M);
 };
if (It == Functions.end())
     return error(Twine("no machine function information for function '") +
                  MF.getName() + "' in the MIR file");
   // TODO: Recreate the machine function.
   const yaml::MachineFunction &YamlMF = *It->getValue();
   if (YamlMF.Alignment)
     MF.setAlignment(YamlMF.Alignment);
   MF.setExposesReturnsTwice(YamlMF.ExposesReturnsTwice);
   MF.setHasInlineAsm(YamlMF.HasInlineAsm);
+  if (initializeRegisterInfo(MF.getRegInfo(), YamlMF))
+    return true;
+
   const auto &F = *MF.getFunction();
   for (const auto &YamlMBB : YamlMF.BasicBlocks) {
     const BasicBlock *BB = nullptr;
     if (!YamlMBB.Name.empty()) {
       BB = dyn_cast_or_null<BasicBlock>(
           F.getValueSymbolTable().lookup(YamlMBB.Name));
       if (!BB)
         return error(Twine("basic block '") + YamlMBB.Name +
if (auto *MI = parseMachineInstr(SM, MF, MISource, Error)) {
       continue;
     }
     reportDiagnostic(Error);
     return true;
   }
   return false;
 }
 
+bool MIRParserImpl::initializeRegisterInfo(
+    MachineRegisterInfo &RegInfo, const yaml::MachineFunction &YamlMF) {
+  assert(RegInfo.isSSA());
+  if (!YamlMF.IsSSA)
+    RegInfo.leaveSSA();
+  assert(RegInfo.tracksLiveness());
+  if (!YamlMF.TracksRegLiveness)
+    RegInfo.invalidateLiveness();
+  RegInfo.enableSubRegLiveness(YamlMF.TracksSubRegLiveness);
+  return false;
+}
+
 SMDiagnostic MIRParserImpl::diagFromLLVMAssemblyDiag(const SMDiagnostic &Error,
                                                      SMRange SourceRange) {
   assert(SourceRange.isValid());
 
   // Translate the location of the error from the location in the llvm IR string
   // to the corresponding location in the MIR file.
   auto LineAndColumn = SM.getLineAndColumn(SourceRange.Start);
   unsigned Line = LineAndColumn.first + Error.getLineNo() - 1;

lib/CodeGen/MIRPrinter.cpp

 // This file implements the class that prints out the LLVM IR and machine
 // functions using the MIR serialization format.
 //
 //===----------------------------------------------------------------------===//
 
 #include "MIRPrinter.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/CodeGen/MIRYamlMapping.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/YAMLTraits.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 
 using namespace llvm;
 
 namespace {
 
 /// This class prints out the machine functions using the MIR serialization
 /// format.
 class MIRPrinter {
   raw_ostream &OS;
 
 public:
   MIRPrinter(raw_ostream &OS) : OS(OS) {}
 
   void print(const MachineFunction &MF);
 
+  void convert(yaml::MachineFunction &MF, const MachineRegisterInfo &RegInfo);
+
   void convert(yaml::MachineBasicBlock &YamlMBB, const MachineBasicBlock &MBB);
 };
 
 /// This class prints out the machine instructions using the MIR serialization
 /// format.
 class MIPrinter {
   raw_ostream &OS;
 

 } // end namespace llvm
 
 void MIRPrinter::print(const MachineFunction &MF) {
   yaml::MachineFunction YamlMF;
   YamlMF.Name = MF.getName();
   YamlMF.Alignment = MF.getAlignment();
   YamlMF.ExposesReturnsTwice = MF.exposesReturnsTwice();
   YamlMF.HasInlineAsm = MF.hasInlineAsm();
+  convert(YamlMF, MF.getRegInfo());
   for (const auto &MBB : MF) {
     yaml::MachineBasicBlock YamlMBB;
     convert(YamlMBB, MBB);
     YamlMF.BasicBlocks.push_back(YamlMBB);
   }
   yaml::Output Out(OS);
   Out << YamlMF;
 }
 
+void MIRPrinter::convert(yaml::MachineFunction &MF,
+                         const MachineRegisterInfo &RegInfo) {
+  MF.IsSSA = RegInfo.isSSA();
+  MF.TracksRegLiveness = RegInfo.tracksLiveness();
+  MF.TracksSubRegLiveness = RegInfo.subRegLivenessEnabled();
+}
+
 void MIRPrinter::convert(yaml::MachineBasicBlock &YamlMBB,
                          const MachineBasicBlock &MBB) {
   // TODO: Serialize unnamed BB references.
   if (const auto *BB = MBB.getBasicBlock())
     YamlMBB.Name = BB->hasName() ? BB->getName() : "<unnamed bb>";
   else
     YamlMBB.Name = "";
   YamlMBB.Alignment = MBB.getAlignment();

test/CodeGen/MIR/machine-function.mir

--- |
   }
   
 ...
 ---
 # CHECK: name: foo
 # CHECK-NEXT: alignment:
 # CHECK-NEXT: exposesReturnsTwice: false
 # CHECK-NEXT: hasInlineAsm: false
-# CHECK-NEXT: ...
+# CHECK: ...
 name:            foo
 ...
 ---
 # CHECK: name: bar
 # CHECK-NEXT: alignment:
 # CHECK-NEXT: exposesReturnsTwice: false
 # CHECK-NEXT: hasInlineAsm: false
-# CHECK-NEXT: ...
+# CHECK: ...
 name:            bar
 ...
 ---
 # CHECK: name: func
 # CHECK-NEXT: alignment: 8
 # CHECK-NEXT: exposesReturnsTwice: false
 # CHECK-NEXT: hasInlineAsm: false
-# CHECK-NEXT: ...
+# CHECK: ...
 name:            func
 alignment:       8
 ...
 ---
 # CHECK: name: func2
 # CHECK-NEXT: alignment: 16
 # CHECK-NEXT: exposesReturnsTwice: true
 # CHECK-NEXT: hasInlineAsm: true
-# CHECK-NEXT: ...
+# CHECK: ...
 name:            func2
 alignment:       16
 exposesReturnsTwice: true
 hasInlineAsm:    true
 ...

test/CodeGen/MIR/register-info.mir

+# RUN: llc -start-after branch-folder -stop-after branch-folder -o /dev/null %s | FileCheck %s
+# This test ensures that the MIR parser parses machine register info properties
+# correctly.
+
+--- |
+
+  define i32 @foo() {
+  entry:
+    ret i32 0
+  }
+
+  define i32 @bar() {
+  start:
+    ret i32 0
+  }
+
+...
+---
+# CHECK: name: foo
+# CHECK:      isSSA: false
+# CHECK-NEXT: tracksRegLiveness: false
+# CHECK-NEXT: tracksSubRegLiveness: false
+# CHECK: ...
+name:            foo
+...
+---
+# CHECK: name: bar
+# CHECK:      isSSA: false
+# CHECK-NEXT: tracksRegLiveness: true
+# CHECK-NEXT: tracksSubRegLiveness: true
+# CHECK: ...
+name: bar
+isSSA: false
+tracksRegLiveness: true
+tracksSubRegLiveness: true
+...