changeset 47658:c2b7fb8e5144

8189355: Cleanup of BarrierSet barrier functions Reviewed-by: shade, kbarrett, pliden, rkennke
author eosterlund
date Thu, 19 Oct 2017 11:25:55 +0200
parents 28b2dbe488f1
children 13783d8ab3f4
files src/hotspot/cpu/arm/stubGenerator_arm.cpp src/hotspot/share/c1/c1_Runtime1.cpp src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.hpp src/hotspot/share/gc/shared/barrierSet.hpp src/hotspot/share/gc/shared/barrierSet.inline.hpp src/hotspot/share/gc/shared/cardTableModRefBS.hpp src/hotspot/share/gc/shared/collectedHeap.cpp src/hotspot/share/gc/shared/modRefBarrierSet.hpp src/hotspot/share/oops/objArrayKlass.cpp src/hotspot/share/prims/jvm.cpp src/hotspot/share/runtime/stubRoutines.cpp
diffstat 11 files changed, 74 insertions(+), 231 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/cpu/arm/stubGenerator_arm.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/cpu/arm/stubGenerator_arm.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -2867,46 +2867,51 @@
   //  Blows all volatile registers (R0-R3 on 32-bit ARM, R0-R18 on AArch64, Rtemp, LR) except for callee_saved_regs.
   void gen_write_ref_array_pre_barrier(Register addr, Register count, int callee_saved_regs) {
     BarrierSet* bs = Universe::heap()->barrier_set();
-    if (bs->has_write_ref_pre_barrier()) {
-      assert(bs->has_write_ref_array_pre_opt(),
-             "Else unsupported barrier set.");
-
-      assert( addr->encoding() < callee_saved_regs, "addr must be saved");
-      assert(count->encoding() < callee_saved_regs, "count must be saved");
-
-      BLOCK_COMMENT("PreBarrier");
+    switch (bs->kind()) {
+    case BarrierSet::G1SATBCTLogging:
+      {
+        assert( addr->encoding() < callee_saved_regs, "addr must be saved");
+        assert(count->encoding() < callee_saved_regs, "count must be saved");
+
+        BLOCK_COMMENT("PreBarrier");
 
 #ifdef AARCH64
-      callee_saved_regs = align_up(callee_saved_regs, 2);
-      for (int i = 0; i < callee_saved_regs; i += 2) {
-        __ raw_push(as_Register(i), as_Register(i+1));
+        callee_saved_regs = align_up(callee_saved_regs, 2);
+        for (int i = 0; i < callee_saved_regs; i += 2) {
+          __ raw_push(as_Register(i), as_Register(i+1));
+        }
+#else
+        RegisterSet saved_regs = RegisterSet(R0, as_Register(callee_saved_regs-1));
+        __ push(saved_regs | R9ifScratched);
+#endif // AARCH64
+
+        if (addr != R0) {
+          assert_different_registers(count, R0);
+          __ mov(R0, addr);
+        }
+#ifdef AARCH64
+        __ zero_extend(R1, count, 32); // BarrierSet::static_write_ref_array_pre takes size_t
+#else
+        if (count != R1) {
+          __ mov(R1, count);
+        }
+#endif // AARCH64
+
+        __ call(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre));
+
+#ifdef AARCH64
+        for (int i = callee_saved_regs - 2; i >= 0; i -= 2) {
+          __ raw_pop(as_Register(i), as_Register(i+1));
+        }
+#else
+        __ pop(saved_regs | R9ifScratched);
+#endif // AARCH64
       }
-#else
-      RegisterSet saved_regs = RegisterSet(R0, as_Register(callee_saved_regs-1));
-      __ push(saved_regs | R9ifScratched);
-#endif // AARCH64
-
-      if (addr != R0) {
-        assert_different_registers(count, R0);
-        __ mov(R0, addr);
-      }
-#ifdef AARCH64
-      __ zero_extend(R1, count, 32); // BarrierSet::static_write_ref_array_pre takes size_t
-#else
-      if (count != R1) {
-        __ mov(R1, count);
-      }
-#endif // AARCH64
-
-      __ call(CAST_FROM_FN_PTR(address, BarrierSet::static_write_ref_array_pre));
-
-#ifdef AARCH64
-      for (int i = callee_saved_regs - 2; i >= 0; i -= 2) {
-        __ raw_pop(as_Register(i), as_Register(i+1));
-      }
-#else
-      __ pop(saved_regs | R9ifScratched);
-#endif // AARCH64
+    case BarrierSet::CardTableForRS:
+    case BarrierSet::CardTableExtension:
+      break;
+    default:
+      ShouldNotReachHere();
     }
   }
 #endif // INCLUDE_ALL_GCS
--- a/src/hotspot/share/c1/c1_Runtime1.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/c1/c1_Runtime1.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1372,8 +1372,6 @@
   // barrier. The assert will fail if this is not the case.
   // Note that we use the non-virtual inlineable variant of write_ref_array.
   BarrierSet* bs = Universe::heap()->barrier_set();
-  assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt");
-  assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well.");
   if (src == dst) {
     // same object, no check
     bs->write_ref_array_pre(dst_addr, length);
--- a/src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.hpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.hpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -54,8 +54,6 @@
   // pre-marking object graph.
   static void enqueue(oop pre_val);
 
-  virtual bool has_write_ref_pre_barrier() { return true; }
-
   // We export this to make it available in cases where the static
   // type of the barrier set is known.  Note that it is non-virtual.
   template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal);
@@ -63,9 +61,6 @@
   // These are the more general virtual versions.
   inline virtual void write_ref_field_pre_work(oop* field, oop new_val);
   inline virtual void write_ref_field_pre_work(narrowOop* field, oop new_val);
-  virtual void write_ref_field_pre_work(void* field, oop new_val) {
-    guarantee(false, "Not needed");
-  }
 
   template <class T> void write_ref_array_pre_work(T* dst, int count);
   virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
--- a/src/hotspot/share/gc/shared/barrierSet.hpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/shared/barrierSet.hpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -80,50 +80,11 @@
 
   // End of fake RTTI support.
 
-public:
-  enum Flags {
-    None                = 0,
-    TargetUninitialized = 1
-  };
-
 protected:
-  // Some barrier sets create tables whose elements correspond to parts of
-  // the heap; the CardTableModRefBS is an example.  Such barrier sets will
-  // normally reserve space for such tables, and commit parts of the table
-  // "covering" parts of the heap that are committed. At most one covered
-  // region per generation is needed.
-  static const int _max_covered_regions = 2;
-
   BarrierSet(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti) { }
   ~BarrierSet() { }
 
 public:
-
-  // These operations indicate what kind of barriers the BarrierSet has.
-  virtual bool has_read_ref_barrier() = 0;
-  virtual bool has_read_prim_barrier() = 0;
-  virtual bool has_write_ref_barrier() = 0;
-  virtual bool has_write_ref_pre_barrier() = 0;
-  virtual bool has_write_prim_barrier() = 0;
-
-  // These functions indicate whether a particular access of the given
-  // kinds requires a barrier.
-  virtual bool read_ref_needs_barrier(void* field) = 0;
-  virtual bool read_prim_needs_barrier(HeapWord* field, size_t bytes) = 0;
-  virtual bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
-                                        juint val1, juint val2) = 0;
-
-  // The first four operations provide a direct implementation of the
-  // barrier set.  An interpreter loop, for example, could call these
-  // directly, as appropriate.
-
-  // Invoke the barrier, if any, necessary when reading the given ref field.
-  virtual void read_ref_field(void* field) = 0;
-
-  // Invoke the barrier, if any, necessary when reading the given primitive
-  // "field" of "bytes" bytes in "obj".
-  virtual void read_prim_field(HeapWord* field, size_t bytes) = 0;
-
   // Invoke the barrier, if any, necessary when writing "new_val" into the
   // ref field at "offset" in "obj".
   // (For efficiency reasons, this operation is specialized for certain
@@ -131,48 +92,19 @@
   // virtual "_work" function below, which must implement the barrier.)
   // First the pre-write versions...
   template <class T> inline void write_ref_field_pre(T* field, oop new_val);
-private:
-  // Helper for write_ref_field_pre and friends, testing for specialized cases.
-  bool devirtualize_reference_writes() const;
 
-  // Keep this private so as to catch violations at build time.
-  virtual void write_ref_field_pre_work(     void* field, oop new_val) { guarantee(false, "Not needed"); };
+  // ...then the post-write version.
+  inline void write_ref_field(void* field, oop new_val, bool release = false);
+
 protected:
   virtual void write_ref_field_pre_work(      oop* field, oop new_val) {};
   virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {};
+  virtual void write_ref_field_work(void* field, oop new_val, bool release) = 0;
+
 public:
-
-  // ...then the post-write version.
-  inline void write_ref_field(void* field, oop new_val, bool release = false);
-protected:
-  virtual void write_ref_field_work(void* field, oop new_val, bool release) = 0;
-public:
-
-  // Invoke the barrier, if any, necessary when writing the "bytes"-byte
-  // value(s) "val1" (and "val2") into the primitive "field".
-  virtual void write_prim_field(HeapWord* field, size_t bytes,
-                                juint val1, juint val2) = 0;
-
   // Operations on arrays, or general regions (e.g., for "clone") may be
   // optimized by some barriers.
 
-  // The first six operations tell whether such an optimization exists for
-  // the particular barrier.
-  virtual bool has_read_ref_array_opt() = 0;
-  virtual bool has_read_prim_array_opt() = 0;
-  virtual bool has_write_ref_array_pre_opt() { return true; }
-  virtual bool has_write_ref_array_opt() = 0;
-  virtual bool has_write_prim_array_opt() = 0;
-
-  virtual bool has_read_region_opt() = 0;
-  virtual bool has_write_region_opt() = 0;
-
-  // These operations should assert false unless the corresponding operation
-  // above returns true.  Otherwise, they should perform an appropriate
-  // barrier for an array whose elements are all in the given memory region.
-  virtual void read_ref_array(MemRegion mr) = 0;
-  virtual void read_prim_array(MemRegion mr) = 0;
-
   // Below length is the # array elements being written
   virtual void write_ref_array_pre(oop* dst, int length,
                                    bool dest_uninitialized = false) {}
@@ -193,17 +125,16 @@
 
 protected:
   virtual void write_ref_array_work(MemRegion mr) = 0;
+
 public:
-  virtual void write_prim_array(MemRegion mr) = 0;
-
-  virtual void read_region(MemRegion mr) = 0;
-
   // (For efficiency reasons, this operation is specialized for certain
   // barrier types.  Semantically, it should be thought of as a call to the
   // virtual "_work" function below, which must implement the barrier.)
   void write_region(MemRegion mr);
+
 protected:
   virtual void write_region_work(MemRegion mr) = 0;
+
 public:
   // Inform the BarrierSet that the the covered heap region that starts
   // with "base" has been changed to have the given size (possibly from 0,
--- a/src/hotspot/share/gc/shared/barrierSet.inline.hpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/shared/barrierSet.inline.hpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,37 +26,15 @@
 #define SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
 
 #include "gc/shared/barrierSet.hpp"
-#include "gc/shared/cardTableModRefBS.inline.hpp"
 #include "utilities/align.hpp"
 
-// Inline functions of BarrierSet, which de-virtualize certain
-// performance-critical calls when the barrier is the most common
-// card-table kind.
-
-inline bool BarrierSet::devirtualize_reference_writes() const {
-  switch (kind()) {
-  case CardTableForRS:
-  case CardTableExtension:
-    return true;
-  default:
-    return false;
-  }
-}
 
 template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) {
-  if (devirtualize_reference_writes()) {
-    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field_pre(field, new_val);
-  } else {
-    write_ref_field_pre_work(field, new_val);
-  }
+  write_ref_field_pre_work(field, new_val);
 }
 
 void BarrierSet::write_ref_field(void* field, oop new_val, bool release) {
-  if (devirtualize_reference_writes()) {
-    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field(field, new_val, release);
-  } else {
-    write_ref_field_work(field, new_val, release);
-  }
+  write_ref_field_work(field, new_val, release);
 }
 
 // count is number of array elements being written
@@ -84,11 +62,7 @@
 
 
 inline void BarrierSet::write_region(MemRegion mr) {
-  if (devirtualize_reference_writes()) {
-    barrier_set_cast<CardTableModRefBS>(this)->inline_write_region(mr);
-  } else {
-    write_region_work(mr);
-  }
+  write_region_work(mr);
 }
 
 #endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
--- a/src/hotspot/share/gc/shared/cardTableModRefBS.hpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/shared/cardTableModRefBS.hpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -73,7 +73,15 @@
   size_t          _byte_map_size;    // in bytes
   jbyte*          _byte_map;         // the card marking array
 
+  // Some barrier sets create tables whose elements correspond to parts of
+  // the heap; the CardTableModRefBS is an example.  Such barrier sets will
+  // normally reserve space for such tables, and commit parts of the table
+  // "covering" parts of the heap that are committed. At most one covered
+  // region per generation is needed.
+  static const int _max_covered_regions = 2;
+
   int _cur_covered_regions;
+
   // The covered regions should be in address order.
   MemRegion* _covered;
   // The committed regions correspond one-to-one to the covered regions.
@@ -89,7 +97,6 @@
   // uncommit the MemRegion for that page.
   MemRegion _guard_region;
 
- protected:
   inline size_t compute_byte_map_size();
 
   // Finds and return the index of the region, if any, to which the given
@@ -135,7 +142,6 @@
     return byte_for(p) + 1;
   }
 
- protected:
   // Dirty the bytes corresponding to "mr" (not all of which must be
   // covered.)
   void dirty_MemRegion(MemRegion mr);
@@ -144,7 +150,7 @@
   // all of which must be covered.)
   void clear_MemRegion(MemRegion mr);
 
-public:
+ public:
   // Constants
   enum SomePublicConstants {
     card_shift                  = 9,
@@ -163,8 +169,6 @@
 
   // *** Barrier set functions.
 
-  bool has_write_ref_pre_barrier() { return false; }
-
   // Initialization utilities; covered_words is the size of the covered region
   // in, um, words.
   inline size_t cards_required(size_t covered_words) {
@@ -173,8 +177,7 @@
     return words / card_size_in_words + 1;
   }
 
-protected:
-
+ protected:
   CardTableModRefBS(MemRegion whole_heap, const BarrierSet::FakeRtti& fake_rtti);
   ~CardTableModRefBS();
 
@@ -185,29 +188,18 @@
 
   void write_ref_field_work(oop obj, size_t offset, oop newVal);
   virtual void write_ref_field_work(void* field, oop newVal, bool release);
-public:
 
-  bool has_write_ref_array_opt() { return true; }
-  bool has_write_region_opt() { return true; }
-
-  inline void inline_write_region(MemRegion mr) {
+ protected:
+  void write_region_work(MemRegion mr) {
     dirty_MemRegion(mr);
   }
-protected:
-  void write_region_work(MemRegion mr) {
-    inline_write_region(mr);
-  }
-public:
 
-  inline void inline_write_ref_array(MemRegion mr) {
+ protected:
+  void write_ref_array_work(MemRegion mr) {
     dirty_MemRegion(mr);
   }
-protected:
-  void write_ref_array_work(MemRegion mr) {
-    inline_write_ref_array(mr);
-  }
-public:
 
+ public:
   bool is_aligned(HeapWord* addr) {
     return is_card_aligned(addr);
   }
--- a/src/hotspot/share/gc/shared/collectedHeap.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/shared/collectedHeap.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -347,7 +347,6 @@
              "Mismatch: multiple objects?");
     }
     BarrierSet* bs = barrier_set();
-    assert(bs->has_write_region_opt(), "No write_region() on BarrierSet");
     bs->write_region(deferred);
     // "Clear" the deferred_card_mark field
     thread->set_deferred_card_mark(MemRegion());
@@ -430,7 +429,6 @@
     } else {
       // Do the card mark
       BarrierSet* bs = barrier_set();
-      assert(bs->has_write_region_opt(), "No write_region() on BarrierSet");
       bs->write_region(mr);
     }
   }
--- a/src/hotspot/share/gc/shared/modRefBarrierSet.hpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/gc/shared/modRefBarrierSet.hpp	Thu Oct 19 11:25:55 2017 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,57 +35,12 @@
 class Generation;
 
 class ModRefBarrierSet: public BarrierSet {
-public:
-
-  // Barriers only on ref writes.
-  bool has_read_ref_barrier() { return false; }
-  bool has_read_prim_barrier() { return false; }
-  bool has_write_ref_barrier() { return true; }
-  bool has_write_prim_barrier() { return false; }
-
-  bool read_ref_needs_barrier(void* field) { return false; }
-  bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
-  bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
-                                juint val1, juint val2) { return false; }
-
-  void write_prim_field(oop obj, size_t offset, size_t bytes,
-                        juint val1, juint val2) {}
-
-  void read_ref_field(void* field) {}
-  void read_prim_field(HeapWord* field, size_t bytes) {}
-
 protected:
-
   ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)
     : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }
   ~ModRefBarrierSet() { }
 
 public:
-  void write_prim_field(HeapWord* field, size_t bytes,
-                        juint val1, juint val2) {}
-
-  bool has_read_ref_array_opt() { return false; }
-  bool has_read_prim_array_opt() { return false; }
-  bool has_write_prim_array_opt() { return false; }
-
-  bool has_read_region_opt() { return false; }
-
-
-  // These operations should assert false unless the corresponding operation
-  // above returns true.
-  void read_ref_array(MemRegion mr) {
-    assert(false, "can't call");
-  }
-  void read_prim_array(MemRegion mr) {
-    assert(false, "can't call");
-  }
-  void write_prim_array(MemRegion mr) {
-    assert(false, "can't call");
-  }
-  void read_region(MemRegion mr) {
-    assert(false, "can't call");
-  }
-
   // Causes all refs in "mr" to be assumed to be modified.
   virtual void invalidate(MemRegion mr) = 0;
 
--- a/src/hotspot/share/oops/objArrayKlass.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/oops/objArrayKlass.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -226,8 +226,6 @@
   // For performance reasons, we assume we are that the write barrier we
   // are using has optimized modes for arrays of references.  At least one
   // of the asserts below will fail if this is not the case.
-  assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt");
-  assert(bs->has_write_ref_array_pre_opt(), "For pre-barrier as well.");
 
   if (s == d) {
     // since source and destination are equal we do not need conversion checks.
--- a/src/hotspot/share/prims/jvm.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/prims/jvm.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -669,7 +669,6 @@
 
   // Store check (mark entire object and let gc sort it out)
   BarrierSet* bs = Universe::heap()->barrier_set();
-  assert(bs->has_write_region_opt(), "Barrier set does not have write_region");
   bs->write_region(MemRegion((HeapWord*)new_obj_oop, size));
 
   Handle new_obj(THREAD, new_obj_oop);
--- a/src/hotspot/share/runtime/stubRoutines.cpp	Wed Oct 18 19:36:17 2017 -0700
+++ b/src/hotspot/share/runtime/stubRoutines.cpp	Thu Oct 19 11:25:55 2017 +0200
@@ -381,14 +381,12 @@
     assert(count != 0, "count should be non-zero");
     assert(count <= (size_t)max_intx, "count too large");
     BarrierSet* bs = Universe::heap()->barrier_set();
-    assert(bs->has_write_ref_array_pre_opt(), "Must have pre-barrier opt");
     bs->write_ref_array_pre(dest, (int)count, dest_uninitialized);
 }
 
 static void gen_arraycopy_barrier(oop* dest, size_t count) {
     assert(count != 0, "count should be non-zero");
     BarrierSet* bs = Universe::heap()->barrier_set();
-    assert(bs->has_write_ref_array_opt(), "Barrier set must have ref array opt");
     bs->write_ref_array((HeapWord*)dest, count);
 }