diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 3ea13b6..ec4b79e 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -1702,14 +1702,15 @@
   }
 }
 
-std::ostream& operator<<(std::ostream& os, const ComparisonBias& rhs) {
+std::ostream& operator<<(std::ostream& os, ComparisonBias rhs) {
+  // TODO: Replace with auto-generated operator<<.
   switch (rhs) {
     case ComparisonBias::kNoBias:
-      return os << "no_bias";
+      return os << "none";
     case ComparisonBias::kGtBias:
-      return os << "gt_bias";
+      return os << "gt";
     case ComparisonBias::kLtBias:
-      return os << "lt_bias";
+      return os << "lt";
     default:
       LOG(FATAL) << "Unknown ComparisonBias: " << static_cast<int>(rhs);
       UNREACHABLE();
@@ -1735,7 +1736,7 @@
   return true;
 }
 
-std::ostream& operator<<(std::ostream& os, const HInstruction::InstructionKind& rhs) {
+std::ostream& operator<<(std::ostream& os, HInstruction::InstructionKind rhs) {
 #define DECLARE_CASE(type, super) case HInstruction::k##type: os << #type; break;
   switch (rhs) {
     FOR_EACH_CONCRETE_INSTRUCTION(DECLARE_CASE)
@@ -2933,28 +2934,6 @@
   return !opt.GetDoesNotNeedDexCache();
 }
 
-std::ostream& operator<<(std::ostream& os, HInvokeStaticOrDirect::MethodLoadKind rhs) {
-  switch (rhs) {
-    case HInvokeStaticOrDirect::MethodLoadKind::kStringInit:
-      return os << "StringInit";
-    case HInvokeStaticOrDirect::MethodLoadKind::kRecursive:
-      return os << "Recursive";
-    case HInvokeStaticOrDirect::MethodLoadKind::kBootImageLinkTimePcRelative:
-      return os << "BootImageLinkTimePcRelative";
-    case HInvokeStaticOrDirect::MethodLoadKind::kBootImageRelRo:
-      return os << "BootImageRelRo";
-    case HInvokeStaticOrDirect::MethodLoadKind::kBssEntry:
-      return os << "BssEntry";
-    case HInvokeStaticOrDirect::MethodLoadKind::kJitDirectAddress:
-      return os << "JitDirectAddress";
-    case HInvokeStaticOrDirect::MethodLoadKind::kRuntimeCall:
-      return os << "RuntimeCall";
-    default:
-      LOG(FATAL) << "Unknown MethodLoadKind: " << static_cast<int>(rhs);
-      UNREACHABLE();
-  }
-}
-
 std::ostream& operator<<(std::ostream& os, HInvokeStaticOrDirect::ClinitCheckRequirement rhs) {
   switch (rhs) {
     case HInvokeStaticOrDirect::ClinitCheckRequirement::kExplicit:
@@ -2990,28 +2969,6 @@
   }
 }
 
-std::ostream& operator<<(std::ostream& os, HLoadClass::LoadKind rhs) {
-  switch (rhs) {
-    case HLoadClass::LoadKind::kReferrersClass:
-      return os << "ReferrersClass";
-    case HLoadClass::LoadKind::kBootImageLinkTimePcRelative:
-      return os << "BootImageLinkTimePcRelative";
-    case HLoadClass::LoadKind::kBootImageRelRo:
-      return os << "BootImageRelRo";
-    case HLoadClass::LoadKind::kBssEntry:
-      return os << "BssEntry";
-    case HLoadClass::LoadKind::kJitBootImageAddress:
-      return os << "JitBootImageAddress";
-    case HLoadClass::LoadKind::kJitTableAddress:
-      return os << "JitTableAddress";
-    case HLoadClass::LoadKind::kRuntimeCall:
-      return os << "RuntimeCall";
-    default:
-      LOG(FATAL) << "Unknown HLoadClass::LoadKind: " << static_cast<int>(rhs);
-      UNREACHABLE();
-  }
-}
-
 bool HLoadString::InstructionDataEquals(const HInstruction* other) const {
   const HLoadString* other_load_string = other->AsLoadString();
   // TODO: To allow GVN for HLoadString from different dex files, we should compare the strings
@@ -3032,26 +2989,6 @@
   }
 }
 
-std::ostream& operator<<(std::ostream& os, HLoadString::LoadKind rhs) {
-  switch (rhs) {
-    case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
-      return os << "BootImageLinkTimePcRelative";
-    case HLoadString::LoadKind::kBootImageRelRo:
-      return os << "BootImageRelRo";
-    case HLoadString::LoadKind::kBssEntry:
-      return os << "BssEntry";
-    case HLoadString::LoadKind::kJitBootImageAddress:
-      return os << "JitBootImageAddress";
-    case HLoadString::LoadKind::kJitTableAddress:
-      return os << "JitTableAddress";
-    case HLoadString::LoadKind::kRuntimeCall:
-      return os << "RuntimeCall";
-    default:
-      LOG(FATAL) << "Unknown HLoadString::LoadKind: " << static_cast<int>(rhs);
-      UNREACHABLE();
-  }
-}
-
 void HInstruction::RemoveEnvironmentUsers() {
   for (const HUseListNode<HEnvironment*>& use : GetEnvUses()) {
     HEnvironment* user = use.GetUser();
@@ -3163,25 +3100,6 @@
   }
 }
 
-std::ostream& operator<<(std::ostream& os, const MemBarrierKind& kind) {
-  switch (kind) {
-    case MemBarrierKind::kAnyStore:
-      return os << "AnyStore";
-    case MemBarrierKind::kLoadAny:
-      return os << "LoadAny";
-    case MemBarrierKind::kStoreStore:
-      return os << "StoreStore";
-    case MemBarrierKind::kAnyAny:
-      return os << "AnyAny";
-    case MemBarrierKind::kNTStoreStore:
-      return os << "NTStoreStore";
-
-    default:
-      LOG(FATAL) << "Unknown MemBarrierKind: " << static_cast<int>(kind);
-      UNREACHABLE();
-  }
-}
-
 // Check that intrinsic enum values fit within space set aside in ArtMethod modifier flags.
 #define CHECK_INTRINSICS_ENUM_VALUES(Name, InvokeType, _, SideEffects, Exceptions, ...) \
   static_assert( \