src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp

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

*** 344,398 ****
      load_reference_barrier_not_null(masm, dst, load_addr);
      __ bind(is_null);
    }
  }
  
  void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                              Register dst, Address src, Register tmp1, Register tmp_thread) {
-   bool on_oop = is_reference_type(type);
-   bool not_in_heap = (decorators & IN_NATIVE) != 0;
-   bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
-   bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
-   bool on_reference = on_weak || on_phantom;
-   bool is_traversal_mode = ShenandoahHeap::heap()->is_traversal_mode();
-   bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0 || is_traversal_mode;
  
    Register result_dst = dst;
  
!   if (on_oop) {
!     // We want to preserve src
      if (dst == src.base() || dst == src.index()) {
        dst = rscratch1;
      }
      assert_different_registers(dst, src.base(), src.index());
    }
  
    BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
!   if (on_oop) {
!     if (not_in_heap && !is_traversal_mode) {
        load_reference_barrier_native(masm, dst, src);
      } else {
        load_reference_barrier(masm, dst, src);
      }
  
      if (dst != result_dst) {
        __ mov(result_dst, dst);
        dst = result_dst;
      }
  
!     if (ShenandoahKeepAliveBarrier && on_reference && keep_alive) {
        __ enter();
        satb_write_barrier_pre(masm /* masm */,
                               noreg /* obj */,
                               dst /* pre_val */,
                               rthread /* thread */,
                               tmp1 /* tmp */,
                               true /* tosca_live */,
                               true /* expand_call */);
        __ leave();
      }
-   }
  }
  
  void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                               Address dst, Register val, Register tmp1, Register tmp2) {
    bool on_oop = is_reference_type(type);
--- 344,414 ----
      load_reference_barrier_not_null(masm, dst, load_addr);
      __ bind(is_null);
    }
  }
  
+ 
+ //
+ // Arguments:
+ //
+ // Inputs:
+ //   src:        oop location to load from, might be clobbered
+ //   tmp1:       unused
+ //   tmp_thread: unused
+ //
+ // Output:
+ //   dst:        oop loaded from src location
+ //
+ // Kill:
+ //   rscratch1 (scratch reg)
+ //
+ // Alias:
+ //   dst: rscratch1 (might use rscratch1 as temporary output register to avoid clobbering src)
+ //
  void ShenandoahBarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                              Register dst, Address src, Register tmp1, Register tmp_thread) {
  
    Register result_dst = dst;
+   bool need_load_reference_barrier = ShenandoahBarrierSet::need_load_reference_barrier(decorators, type);
  
!   // Only preserve src address if we need load reference barrier
!   if (need_load_reference_barrier) {
!     // Use rscratch1 as temporary output register to avoid clobbering src
      if (dst == src.base() || dst == src.index()) {
        dst = rscratch1;
      }
      assert_different_registers(dst, src.base(), src.index());
    }
  
    BarrierSetAssembler::load_at(masm, decorators, type, dst, src, tmp1, tmp_thread);
!   if (!need_load_reference_barrier) {
!     return;
!   }
! 
!   if (ShenandoahBarrierSet::use_native_load_reference_barrier(decorators, type)) {
      load_reference_barrier_native(masm, dst, src);
    } else {
      load_reference_barrier(masm, dst, src);
    }
  
+   // Move loaded oop to final destination
    if (dst != result_dst) {
      __ mov(result_dst, dst);
      dst = result_dst;
    }
  
!   if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) {
      __ enter();
      satb_write_barrier_pre(masm /* masm */,
                             noreg /* obj */,
                             dst /* pre_val */,
                             rthread /* thread */,
                             tmp1 /* tmp */,
                             true /* tosca_live */,
                             true /* expand_call */);
      __ leave();
    }
  }
  
  void ShenandoahBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                               Address dst, Register val, Register tmp1, Register tmp2) {
    bool on_oop = is_reference_type(type);