diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index afa17ce..8c64d25 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -5762,7 +5762,6 @@
       : HInstruction(SideEffectsForArchRuntimeCalls(), dex_pc),
         special_input_(HUserRecord<HInstruction*>(current_method)),
         string_index_(string_index) {
-    SetPackedFlag<kFlagIsInDexCache>(false);
     SetPackedField<LoadKindField>(LoadKind::kDexCacheViaMethod);
     load_data_.dex_file_ = &dex_file;
   }
@@ -5789,7 +5788,6 @@
   const DexFile& GetDexFile() const;
 
   dex::StringIndex GetStringIndex() const {
-    DCHECK(HasStringReference(GetLoadKind()) || /* For slow paths. */ !IsInDexCache());
     return string_index_;
   }
 
@@ -5814,7 +5812,7 @@
         load_kind == LoadKind::kJitTableAddress) {
       return false;
     }
-    return !IsInDexCache();
+    return true;
   }
 
   bool NeedsDexCacheOfDeclaringClass() const OVERRIDE {
@@ -5828,15 +5826,6 @@
     return SideEffects::CanTriggerGC();
   }
 
-  bool IsInDexCache() const { return GetPackedFlag<kFlagIsInDexCache>(); }
-
-  void MarkInDexCache() {
-    SetPackedFlag<kFlagIsInDexCache>(true);
-    DCHECK(!NeedsEnvironment());
-    RemoveEnvironment();
-    SetSideEffects(SideEffects::None());
-  }
-
   void AddSpecialInput(HInstruction* special_input);
 
   using HInstruction::GetInputRecords;  // Keep the const version visible.
@@ -5852,8 +5841,7 @@
   DECLARE_INSTRUCTION(LoadString);
 
  private:
-  static constexpr size_t kFlagIsInDexCache = kNumberOfGenericPackedBits;
-  static constexpr size_t kFieldLoadKind = kFlagIsInDexCache + 1;
+  static constexpr size_t kFieldLoadKind = kNumberOfGenericPackedBits;
   static constexpr size_t kFieldLoadKindSize =
       MinimumBitsToStore(static_cast<size_t>(LoadKind::kLast));
   static constexpr size_t kNumberOfLoadStringPackedBits = kFieldLoadKind + kFieldLoadKindSize;
diff --git a/compiler/optimizing/sharpening.cc b/compiler/optimizing/sharpening.cc
index 9fdeccf..ca26c30 100644
--- a/compiler/optimizing/sharpening.cc
+++ b/compiler/optimizing/sharpening.cc
@@ -270,7 +270,6 @@
 
 void HSharpening::ProcessLoadString(HLoadString* load_string) {
   DCHECK_EQ(load_string->GetLoadKind(), HLoadString::LoadKind::kDexCacheViaMethod);
-  DCHECK(!load_string->IsInDexCache());
 
   const DexFile& dex_file = load_string->GetDexFile();
   dex::StringIndex string_index = load_string->GetStringIndex();
diff --git a/runtime/gc/collector/concurrent_copying.cc b/runtime/gc/collector/concurrent_copying.cc
index b889913..dccec9f 100644
--- a/runtime/gc/collector/concurrent_copying.cc
+++ b/runtime/gc/collector/concurrent_copying.cc
@@ -843,8 +843,26 @@
         ss << "\n";
         Locks::mutator_lock_->Dump(ss);
         ss << "\n";
-        runtime->GetThreadList()->Dump(ss);
-        LOG(FATAL) << ss.str();
+        LOG(FATAL_WITHOUT_ABORT) << ss.str();
+        // Some threads in 'runnable_thread_ids' are probably stuck. Try to dump their stacks.
+        // Avoid using ThreadList::Dump() because it is likely to get stuck as well.
+        {
+          ReaderMutexLock mu0(self, *Locks::mutator_lock_);
+          MutexLock mu1(self, *Locks::thread_list_lock_);
+          for (Thread* thread : runtime->GetThreadList()->GetList()) {
+            uint32_t tid = thread->GetThreadId();
+            bool is_in_runnable_thread_ids =
+                std::find(runnable_thread_ids.begin(), runnable_thread_ids.end(), tid) !=
+                runnable_thread_ids.end();
+            if (is_in_runnable_thread_ids &&
+                thread->ReadFlag(kEmptyCheckpointRequest)) {
+              // Found a runnable thread that hasn't responded to the empty checkpoint request.
+              // Assume it's stuck and safe to dump its stack.
+              thread->Dump(LOG_STREAM(FATAL_WITHOUT_ABORT));
+            }
+          }
+        }
+        LOG(FATAL) << "Dumped runnable threads that haven't responded to empty checkpoint.";
       }
     } else {
       barrier->Increment(self, barrier_count);