[X86] Fix uninitialized variable warnings. NFCI.

lib/Target/X86/X86AvoidStoreForwardingBlocks.cpp

@@ -83,13 +83,13 @@ public:
   }
 
 private:
-  MachineRegisterInfo *MRI;
-  const X86InstrInfo *TII;
-  const X86RegisterInfo *TRI;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86InstrInfo *TII = nullptr;
+  const X86RegisterInfo *TRI = nullptr;
   SmallVector<std::pair<MachineInstr *, MachineInstr *>, 2>
       BlockedLoadsStoresPairs;
   SmallVector<MachineInstr *, 2> ForRemoval;
-  AliasAnalysis *AA;
+  AliasAnalysis *AA = nullptr;
 
   /// Returns couples of Load then Store to memory which look
   ///  like a memcpy.

lib/Target/X86/X86FixupLEAs.cpp

@@ -113,8 +113,8 @@ public:
 
 private:
   TargetSchedModel TSM;
-  const X86InstrInfo *TII;
-  const X86RegisterInfo *TRI;
+  const X86InstrInfo *TII = nullptr;
+  const X86RegisterInfo *TRI = nullptr;
 };
 }
 

lib/Target/X86/X86FixupSetCC.cpp

@@ -54,8 +54,8 @@ private:
   // output.
   bool isSetCCr(unsigned Opode);
 
-  MachineRegisterInfo *MRI;
-  const X86InstrInfo *TII;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86InstrInfo *TII = nullptr;
 
   enum { SearchBound = 16 };
 

lib/Target/X86/X86FlagsCopyLowering.cpp

@@ -87,12 +87,12 @@ public:
   static char ID;
 
 private:
-  MachineRegisterInfo *MRI;
-  const X86Subtarget *Subtarget;
-  const X86InstrInfo *TII;
-  const TargetRegisterInfo *TRI;
-  const TargetRegisterClass *PromoteRC;
-  MachineDominatorTree *MDT;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86Subtarget *Subtarget = nullptr;
+  const X86InstrInfo *TII = nullptr;
+  const TargetRegisterInfo *TRI = nullptr;
+  const TargetRegisterClass *PromoteRC = nullptr;
+  MachineDominatorTree *MDT = nullptr;
 
   CondRegArray collectCondsInRegs(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator CopyDefI);
@@ -779,10 +779,10 @@ void X86FlagsCopyLoweringPass::rewriteArithmetic(
     CondRegArray &CondRegs) {
   // Arithmetic is either reading CF or OF. Figure out which condition we need
   // to preserve in a register.
-  X86::CondCode Cond;
+  X86::CondCode Cond = X86::COND_INVALID;
 
   // The addend to use to reset CF or OF when added to the flag value.
-  int Addend;
+  int Addend = 0;
 
   switch (getMnemonicFromOpcode(MI.getOpcode())) {
   case FlagArithMnemonic::ADC:

lib/Target/X86/X86IndirectBranchTracking.cpp

@@ -48,10 +48,10 @@ private:
   static char ID;
 
   /// Machine instruction info used throughout the class.
-  const X86InstrInfo *TII;
+  const X86InstrInfo *TII = nullptr;
 
   /// Endbr opcode for the current machine function.
-  unsigned int EndbrOpcode;
+  unsigned int EndbrOpcode = 0;
 
   /// Adds a new ENDBR instruction to the beginning of the MBB.
   /// The function will not add it if already exists.

lib/Target/X86/X86OptimizeLEAs.cpp

@@ -294,9 +294,9 @@ private:
 
   DenseMap<const MachineInstr *, unsigned> InstrPos;
 
-  MachineRegisterInfo *MRI;
-  const X86InstrInfo *TII;
-  const X86RegisterInfo *TRI;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86InstrInfo *TII = nullptr;
+  const X86RegisterInfo *TRI = nullptr;
 };
 
 } // end anonymous namespace

lib/Target/X86/X86RetpolineThunks.cpp

@@ -63,13 +63,13 @@ public:
   }
 
 private:
-  MachineModuleInfo *MMI;
-  const TargetMachine *TM;
-  bool Is64Bit;
-  const X86Subtarget *STI;
-  const X86InstrInfo *TII;
+  MachineModuleInfo *MMI = nullptr;
+  const TargetMachine *TM = nullptr;
+  bool Is64Bit = false;
+  const X86Subtarget *STI = nullptr;
+  const X86InstrInfo *TII = nullptr;
 
-  bool InsertedThunks;
+  bool InsertedThunks = false;
 
   void createThunkFunction(Module &M, StringRef Name);
   void insertRegReturnAddrClobber(MachineBasicBlock &MBB, unsigned Reg);

lib/Target/X86/X86SpeculativeLoadHardening.cpp

@@ -148,8 +148,8 @@ private:
 
   /// Manages the predicate state traced through the program.
   struct PredState {
-    unsigned InitialReg;
-    unsigned PoisonReg;
+    unsigned InitialReg = 0;
+    unsigned PoisonReg = 0;
 
     const TargetRegisterClass *RC;
     MachineSSAUpdater SSA;
@@ -158,10 +158,10 @@ private:
         : RC(RC), SSA(MF) {}
   };
 
-  const X86Subtarget *Subtarget;
-  MachineRegisterInfo *MRI;
-  const X86InstrInfo *TII;
-  const TargetRegisterInfo *TRI;
+  const X86Subtarget *Subtarget = nullptr;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86InstrInfo *TII = nullptr;
+  const TargetRegisterInfo *TRI = nullptr;
 
   Optional<PredState> PS;
 

lib/Target/X86/X86WinAllocaExpander.cpp

@@ -54,14 +54,14 @@ private:
   /// Lower a WinAlloca instruction.
   void lower(MachineInstr* MI, Lowering L);
 
-  MachineRegisterInfo *MRI;
-  const X86Subtarget *STI;
-  const TargetInstrInfo *TII;
-  const X86RegisterInfo *TRI;
-  unsigned StackPtr;
-  unsigned SlotSize;
-  int64_t StackProbeSize;
-  bool NoStackArgProbe;
+  MachineRegisterInfo *MRI = nullptr;
+  const X86Subtarget *STI = nullptr;
+  const TargetInstrInfo *TII = nullptr;
+  const X86RegisterInfo *TRI = nullptr;
+  unsigned StackPtr = 0;
+  unsigned SlotSize = 0;
+  int64_t StackProbeSize = 0;
+  bool NoStackArgProbe = false;
 
   StringRef getPassName() const override { return "X86 WinAlloca Expander"; }
   static char ID;

lib/Target/X86/X86WinEHState.cpp

@@ -91,7 +91,7 @@ private:
   EHPersonality Personality = EHPersonality::Unknown;
   Function *PersonalityFn = nullptr;
   bool UseStackGuard = false;
-  int ParentBaseState;
+  int ParentBaseState = 0;
   FunctionCallee SehLongjmpUnwind = nullptr;
   Constant *Cookie = nullptr;