src/hotspot/cpu/x86/gc/g1/g1BarrierSetAssembler_x86.cpp

@@ -1,7 +1,7 @@
  /*
-  * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2018, 2026, 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
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.

@@ -28,10 +28,11 @@
  #include "gc/g1/g1BarrierSetRuntime.hpp"
  #include "gc/g1/g1CardTable.hpp"
  #include "gc/g1/g1HeapRegion.hpp"
  #include "gc/g1/g1ThreadLocalData.hpp"
  #include "interpreter/interp_masm.hpp"
+ #include "runtime/arguments.hpp"
  #include "runtime/sharedRuntime.hpp"
  #include "utilities/debug.hpp"
  #include "utilities/macros.hpp"
  #ifdef COMPILER1
  #include "c1/c1_LIRAssembler.hpp"

@@ -378,12 +379,13 @@
  
  void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                           Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
    bool in_heap = (decorators & IN_HEAP) != 0;
    bool as_normal = (decorators & AS_NORMAL) != 0;
+   bool dest_uninitialized = (decorators & IS_DEST_UNINITIALIZED) != 0;
  
-   bool needs_pre_barrier = as_normal;
+   bool needs_pre_barrier = as_normal && !dest_uninitialized;
    bool needs_post_barrier = val != noreg && in_heap;
  
    // flatten object address if needed
    // We do it regardless of precise because we need the registers
    if (dst.index() == noreg && dst.disp() == 0) {