# HG changeset patch
# Parent f1564f9e0ff9c7fbbf0eb0b147b44bc9d8f2ad6d

diff -r f1564f9e0ff9 src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Mon Jul 09 12:30:23 2018 -0400
+++ b/src/hotspot/cpu/aarch64/gc/shenandoah/shenandoahBarrierSetAssembler_aarch64.cpp	Mon Jul 09 12:39:58 2018 -0400
@@ -266,43 +266,40 @@
 }
 
 void ShenandoahBarrierSetAssembler::write_barrier_impl(MacroAssembler* masm, Register dst) {
-  assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "should be enabled");
-  assert(dst != rscratch1, "different regs");
-  assert(dst != rscratch2, "Need rscratch2");
+  assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");
+  assert(dst != rscratch1, "need rscratch1");
+  assert(dst != rscratch2, "need rscratch2");
 
   Label done;
 
   Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
   __ ldrb(rscratch1, gc_state);
-  __ membar(Assembler::LoadLoad);
 
-  // Now check if evacuation is in progress.
-  read_barrier_not_null(masm, dst);
+  // Check for heap stability
+  __ cbz(rscratch1, done);
 
+  // Heap is unstable, need to perform the read-barrier even if WB is inactive
+  if (ShenandoahWriteBarrierRB) {
+    __ ldr(dst, Address(dst, BrooksPointer::byte_offset()));
+  }
+
+  // Check for evacuation-in-progress and jump to WB slow-path if needed
   __ mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
   __ tst(rscratch1, rscratch2);
   __ br(Assembler::EQ, done);
 
-  __ lsr(rscratch1, dst, ShenandoahHeapRegion::region_size_bytes_shift_jint());
-  __ mov(rscratch2,  ShenandoahHeap::in_cset_fast_test_addr());
-  __ ldrb(rscratch2, Address(rscratch2, rscratch1));
-  __ tst(rscratch2, 0x1);
-  __ br(Assembler::EQ, done);
+  RegSet to_save = RegSet::of(r0);
+  if (dst != r0) {
+    __ push(to_save, sp);
+    __ mov(r0, dst);
+  }
 
-  // Save possibly live regs.
-  RegSet live_regs = RegSet::range(r0, r4) - dst;
-  __ push(live_regs, sp);
-  __ strd(v0, __ pre(sp, 2 * -wordSize));
+  __ far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb())));
 
-  // Call into runtime
-  __ super_call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_IRT), dst);
-
-  // Move result into dst reg.
-  __ mov(dst, r0);
-
-  // Restore possibly live regs.
-  __ ldrd(v0, __ post(sp, 2 * wordSize));
-  __ pop(live_regs, sp);
+  if (dst != r0) {
+    __ mov(dst, r0);
+    __ pop(to_save, sp);
+  }
 
   __ bind(done);
 }
@@ -541,7 +538,7 @@
     __ cbz(res, done);
   }
 
-  __ shenandoah_write_barrier(res);
+  write_barrier(ce->masm(), res);
 
   __ bind(done);
 }
diff -r f1564f9e0ff9 src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp
--- a/src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp	Mon Jul 09 12:30:23 2018 -0400
+++ b/src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp	Mon Jul 09 12:39:58 2018 -0400
@@ -4037,48 +4037,6 @@
   access_store_at(T_OBJECT, IN_HEAP, dst, noreg, noreg, noreg);
 }
 
-#if INCLUDE_SHENANDOAHGC
-void MacroAssembler::shenandoah_write_barrier(Register dst) {
-  assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");
-  assert(dst != rscratch1, "need rscratch1");
-  assert(dst != rscratch2, "need rscratch2");
-
-  Label done;
-
-  Address gc_state(rthread, in_bytes(ShenandoahThreadLocalData::gc_state_offset()));
-  ldrb(rscratch1, gc_state);
-
-  // Check for heap stability
-  cbz(rscratch1, done);
-
-  // Heap is unstable, need to perform the read-barrier even if WB is inactive
-  if (ShenandoahWriteBarrierRB) {
-    ldr(dst, Address(dst, BrooksPointer::byte_offset()));
-  }
-
-  // Check for evacuation-in-progress and jump to WB slow-path if needed
-  mov(rscratch2, ShenandoahHeap::EVACUATION | ShenandoahHeap::TRAVERSAL);
-  tst(rscratch1, rscratch2);
-  br(Assembler::EQ, done);
-
-  RegSet to_save = RegSet::of(r0);
-  if (dst != r0) {
-    push(to_save, sp);
-    mov(r0, dst);
-  }
-
-  far_call(RuntimeAddress(CAST_FROM_FN_PTR(address, ShenandoahBarrierSetAssembler::shenandoah_wb())));
-
-  if (dst != r0) {
-    mov(dst, r0);
-    pop(to_save, sp);
-  }
-  block_comment("} Shenandoah write barrier");
-
-  bind(done);
-}
-#endif // INCLUDE_SHENANDOAHGC
-
 Address MacroAssembler::allocate_metadata_address(Metadata* obj) {
   assert(oop_recorder() != NULL, "this assembler needs a Recorder");
   int index = oop_recorder()->allocate_metadata_index(obj);
diff -r f1564f9e0ff9 src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp
--- a/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Mon Jul 09 12:30:23 2018 -0400
+++ b/src/hotspot/cpu/aarch64/macroAssembler_aarch64.hpp	Mon Jul 09 12:39:58 2018 -0400
@@ -795,10 +795,6 @@
 
   void resolve_jobject(Register value, Register thread, Register tmp);
 
-#if INCLUDE_SHENANDOAHGC
-  void shenandoah_write_barrier(Register dst);
-#endif
-
   // oop manipulations
   void load_klass(Register dst, Register src);
   void store_klass(Register dst, Register src);