src/hotspot/cpu/ppc/gc/g1/g1BarrierSetAssembler_ppc.cpp

@@ -1,8 +1,8 @@
  /*
-  * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
-  * Copyright (c) 2018, 2025 SAP SE. All rights reserved.
+  * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2018, 2026 SAP SE. 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.

@@ -279,26 +279,34 @@
  
  void G1BarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                         Register base, RegisterOrConstant ind_or_offs, Register val,
                                         Register tmp1, Register tmp2, Register tmp3,
                                         MacroAssembler::PreservationLevel preservation_level) {
+   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 && !dest_uninitialized;
+   bool needs_post_barrier = (val != noreg && in_heap);
    bool is_array = (decorators & IS_ARRAY) != 0;
    bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
    bool precise = is_array || on_anonymous;
+ 
    // Load and record the previous value.
-   g1_write_barrier_pre(masm, decorators,
-                        base, ind_or_offs,
-                        tmp1, tmp2, tmp3,
-                        preservation_level);
+   if (needs_pre_barrier) {
+     g1_write_barrier_pre(masm, decorators,
+                          base, ind_or_offs,
+                          tmp1, tmp2, tmp3,
+                          preservation_level);
+   }
  
    BarrierSetAssembler::store_at(masm, decorators,
                                  type, base, ind_or_offs, val,
                                  tmp1, tmp2, tmp3,
                                  preservation_level);
  
    // No need for post barrier if storing null
-   if (val != noreg) {
+   if (needs_post_barrier) {
      if (precise) {
        if (ind_or_offs.is_constant()) {
          __ add_const_optimized(base, base, ind_or_offs.as_constant(), tmp1);
        } else {
          __ add(base, ind_or_offs.as_register(), base);