src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp

rev 56771 : 8233339: Shenandoah: Centralize load barrier decisions into ShenandoahBarrierSet

@@ -533,58 +533,58 @@
   return BarrierSetC2::store_at_resolved(access, val);
 }
 
 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
   DecoratorSet decorators = access.decorators();
+  BasicType type = access.type();
+
+  assert((decorators & AS_RAW) == 0, "Unexpected decorator");
+  assert((decorators & AS_NO_KEEPALIVE) == 0, "Unexpected decorator");
 
   Node* adr = access.addr().node();
   Node* obj = access.base();
 
   bool mismatched = (decorators & C2_MISMATCHED) != 0;
   bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
   bool on_heap = (decorators & IN_HEAP) != 0;
   bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0;
   bool is_unordered = (decorators & MO_UNORDERED) != 0;
   bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
-  bool is_traversal_mode = ShenandoahHeap::heap()->is_traversal_mode();
-  bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0 || is_traversal_mode;
-  bool in_native = (decorators & IN_NATIVE) != 0;
 
   Node* top = Compile::current()->top();
 
   Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top;
   Node* load = BarrierSetC2::load_at_resolved(access, val_type);
+  if (!ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) {
+    return load;
+  }
 
-  if (access.is_oop()) {
-    if (ShenandoahLoadRefBarrier) {
-      load = new ShenandoahLoadReferenceBarrierNode(NULL, load, in_native && !is_traversal_mode);
+  load = new ShenandoahLoadReferenceBarrierNode(NULL, load, ShenandoahBarrierSet::use_native_load_reference_barrier(decorators, type));
       if (access.is_parse_access()) {
         load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load);
       } else {
         load = static_cast<C2OptAccess &>(access).gvn().transform(load);
       }
-    }
-  }
 
+  if (!ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
+    return load;
+  }
   // If we are reading the value of the referent field of a Reference
   // object (either by using Unsafe directly or through reflection)
   // then, if SATB is enabled, we need to record the referent in an
   // SATB log buffer using the pre-barrier mechanism.
   // Also we need to add memory barrier to prevent commoning reads
   // from this field across safepoint since GC can change its value.
-  bool need_read_barrier = ShenandoahKeepAliveBarrier &&
-    (on_weak_ref || (unknown && offset != top && obj != top));
-
-  if (!access.is_oop() || !need_read_barrier) {
+  if (unknown && (offset == top || obj == top)) {
     return load;
   }
 
   assert(access.is_parse_access(), "entry not supported at optimization time");
   C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
   GraphKit* kit = parse_access.kit();
 
-  if (on_weak_ref && keep_alive) {
+  if (on_weak_ref) {
     // Use the pre-barrier to record the value in the referent field
     satb_write_barrier_pre(kit, false /* do_load */,
                            NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
                            load /* pre_val */, T_OBJECT);
     // Add memory barrier to prevent commoning reads from this field