diff --git a/llvm/lib/Target/X86/X86FixupBWInsts.cpp b/llvm/lib/Target/X86/X86FixupBWInsts.cpp
--- a/llvm/lib/Target/X86/X86FixupBWInsts.cpp
+++ b/llvm/lib/Target/X86/X86FixupBWInsts.cpp
@@ -148,8 +148,8 @@
   /// Register Liveness information after the current instruction.
   LivePhysRegs LiveRegs;
 
-  ProfileSummaryInfo *PSI;
-  MachineBlockFrequencyInfo *MBFI;
+  ProfileSummaryInfo *PSI = nullptr;
+  MachineBlockFrequencyInfo *MBFI = nullptr;
 };
 char FixupBWInstPass::ID = 0;
 }
diff --git a/llvm/lib/Target/X86/X86LoadValueInjectionLoadHardening.cpp b/llvm/lib/Target/X86/X86LoadValueInjectionLoadHardening.cpp
--- a/llvm/lib/Target/X86/X86LoadValueInjectionLoadHardening.cpp
+++ b/llvm/lib/Target/X86/X86LoadValueInjectionLoadHardening.cpp
@@ -154,9 +154,9 @@
   using EdgeSet = MachineGadgetGraph::EdgeSet;
   using NodeSet = MachineGadgetGraph::NodeSet;
 
-  const X86Subtarget *STI;
-  const TargetInstrInfo *TII;
-  const TargetRegisterInfo *TRI;
+  const X86Subtarget *STI = nullptr;
+  const TargetInstrInfo *TII = nullptr;
+  const TargetRegisterInfo *TRI = nullptr;
 
   std::unique_ptr<MachineGadgetGraph>
   getGadgetGraph(MachineFunction &MF, const MachineLoopInfo &MLI,
diff --git a/llvm/lib/Target/X86/X86PartialReduction.cpp b/llvm/lib/Target/X86/X86PartialReduction.cpp
--- a/llvm/lib/Target/X86/X86PartialReduction.cpp
+++ b/llvm/lib/Target/X86/X86PartialReduction.cpp
@@ -33,8 +33,8 @@
 namespace {
 
 class X86PartialReduction : public FunctionPass {
-  const DataLayout *DL;
-  const X86Subtarget *ST;
+  const DataLayout *DL = nullptr;
+  const X86Subtarget *ST = nullptr;
 
 public:
   static char ID; // Pass identification, replacement for typeid.
diff --git a/llvm/lib/Target/X86/X86PreTileConfig.cpp b/llvm/lib/Target/X86/X86PreTileConfig.cpp
--- a/llvm/lib/Target/X86/X86PreTileConfig.cpp
+++ b/llvm/lib/Target/X86/X86PreTileConfig.cpp
@@ -98,8 +98,8 @@
 };
 
 class X86PreTileConfig : public MachineFunctionPass {
-  MachineRegisterInfo *MRI;
-  const MachineLoopInfo *MLI;
+  MachineRegisterInfo *MRI = nullptr;
+  const MachineLoopInfo *MLI = nullptr;
   SmallSet<MachineInstr *, 8> DefVisited;
   DenseMap<MachineBasicBlock *, BBInfo> BBVisitedInfo;
   DenseMap<MachineBasicBlock *, SmallVector<MIRef, 8>> ShapeBBs;