src/hotspot/share/gc/shared/c2/modRefBarrierSetC2.cpp

*** 36,19 ***
    bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
    bool in_heap = (decorators & IN_HEAP) != 0;
    bool use_precise = is_array || anonymous;
    bool tightly_coupled_alloc = (decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0;
  
!   if (!access.is_oop() || tightly_coupled_alloc || (!in_heap && !anonymous)) {
      return BarrierSetC2::store_at_resolved(access, val);
    }
  
    assert(access.is_parse_access(), "entry not supported at optimization time");
    C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
  
    Node* store = BarrierSetC2::store_at_resolved(access, val);
!   post_barrier(parse_access.kit(), access.base(), adr, val.node(), use_precise);
  
    return store;
  }
  
  Node* ModRefBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
--- 36,42 ---
    bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
    bool in_heap = (decorators & IN_HEAP) != 0;
    bool use_precise = is_array || anonymous;
    bool tightly_coupled_alloc = (decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0;
  
!   const InlineTypeNode* vt = nullptr;
+   if (access.is_parse_access() && static_cast<C2ParseAccess&>(access).vt() != nullptr) {
+     vt = static_cast<C2ParseAccess&>(access).vt();
+   }
+ 
+   if (vt == nullptr && (!access.is_oop() || tightly_coupled_alloc || (!in_heap && !anonymous))) {
      return BarrierSetC2::store_at_resolved(access, val);
    }
  
    assert(access.is_parse_access(), "entry not supported at optimization time");
    C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
  
    Node* store = BarrierSetC2::store_at_resolved(access, val);
! 
+   // TODO 8350865
+   // - We actually only need the post barrier once for non-arrays (same for C1, right)?
+   // - Value is only needed to determine if we are storing null. Maybe we can go with a simple boolean?
+   GraphKit* kit = parse_access.kit();
+   if (vt != nullptr) {
+     for (uint i = 0; i < vt->field_count(); ++i) {
+       ciType* type = vt->field_type(i);
+       if (!type->is_primitive_type()) {
+         ciInlineKlass* vk = vt->bottom_type()->inline_klass();
+         int field_offset = vt->field_offset(i) - vk->payload_offset();
+         Node* value = vt->field_value(i);
+         Node* field_adr = kit->basic_plus_adr(access.base(), adr, field_offset);
+         post_barrier(kit, access.base(), field_adr, value, use_precise);
+       }
+     }
+   } else {
+     post_barrier(kit, access.base(), adr, val.node(), use_precise);
+   }
  
    return store;
  }
  
  Node* ModRefBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,