src/hotspot/cpu/aarch64/stubGenerator_aarch64.cpp

*** 562,573 ****
      StubCodeMark mark(this, "StubRoutines", "shenandoah_wb");
  
      __ align(6);
      address start = __ pc();
  
-     Label slow_case, lose, not_an_instance, is_array;
- 
      if (do_cset_test) {
        Label work;
        __ mov(rscratch2, ShenandoahHeap::in_cset_fast_test_addr());
        __ lsr(rscratch1, r0, ShenandoahHeapRegion::region_size_bytes_shift_jint());
        __ ldrb(rscratch2, Address(rscratch2, rscratch1));
--- 562,571 ----
*** 575,707 ****
        __ ret(lr);
        __ bind(work);
      }
  
      Register obj = r0;
-     if (UseTLAB && ShenandoahAsmWB) {
-       RegSet saved = RegSet::range(r1, r4);
-       if (!c_abi) {
-         __ push(saved, sp);
-       }
- 
-       Register size = r2, newobj = r3, newobj_end = rscratch2;
- 
-       __ ldr(newobj, Address(rthread, JavaThread::gclab_top_offset()));
-       __ cbz(newobj, slow_case); // No GCLAB
- 
-       __ load_klass(r1, obj);
- 
-       __ ldrw(size, Address(r1, Klass::layout_helper_offset()));
-       __ tbnz(size, BitsPerInt - 1, not_an_instance);  // make sure it's an instance (LH > 0)
-       assert(Klass::_lh_neutral_value == 0, "must be");
-       __ cbzw(size, slow_case);
-       __ tbnz(size, exact_log2(Klass::_lh_instance_slow_path_bit), slow_case);
-       __ bind(is_array);
- 
-       // size contains the size (in bytes) of the object.
- 
-       // Make sure it's not a really big object.
-       // ??? Maybe this test is not necessary.
-       __ cmp(size, 128 * HeapWordSize);
-       __ br(Assembler::GE, slow_case);
- 
-       int oop_extra_words = Universe::heap()->oop_extra_words();
-       __ add(newobj_end, newobj, oop_extra_words * HeapWordSize);
-       __ add(newobj_end, newobj_end, size, ext::uxtw);
- 
-       // Pointer to end of new object is in newobj_end.
- 
-       __ ldr(rscratch1, Address(rthread, JavaThread::gclab_end_offset()));
-       __ cmp(newobj_end, rscratch1);
-       __ br(Assembler::HS, slow_case); // No room in GCLAB
- 
-       // Store Brooks pointer and adjust start of newobj.
-       Universe::heap()->compile_prepare_oop(_masm, newobj);
- 
-       // We can reuse newobj_end (rscratch2) to hold dst.
-       Register src = r1, dst = newobj_end;
- 
-       // Copy the object from obj to newobj.  This loop is short and
-       // sweet: the typical size of an object is about eight HeapWords
-       // so it makes no sense to optimize for a large memory copy.
-       // There might be some sense to calling generate_copy_longs from
-       // here if the object to be copied is very large.
-       Label loop, odd_count;
-       {
-         __ mov(src, obj);
-         __ mov(dst, newobj);
-         __ tbnz(size, exact_log2(HeapWordSize), odd_count);
- 
-         // Live registers: obj, newobj, size, src, dst.
- 
-         __ bind(loop);
-         // Count is even.  Copy pairs of HeapWords.
-         __ ldp(rscratch1, r4, __ post(src, 2 * HeapWordSize));
-         __ stp(rscratch1, r4, __ post(dst, 2 * HeapWordSize));
-         __ subs(size, size, 2 * HeapWordSize);
-         __ br(Assembler::GT, loop);
-       }
- 
-       // All copied.  Now try to CAS the Brooks pointer.
-       Label succeed;
-       __ lea(r2, Address(obj, BrooksPointer::byte_offset()));
-       __ cmpxchgptr(obj, newobj, r2, rscratch1, succeed, NULL);
-       // If we lose the CAS we are racing with someone who just beat
-       // us evacuating the object.  This leaves the address of the
-       // evacuated object in r0.
- 
-       // We lost.
-       if (!c_abi) {
-         __ pop(saved, sp);
-       }
-       __ ret(lr);
- 
-       // We won.
-       __ bind(succeed);
-       __ mov(obj, newobj);
-       // dst points to end of newobj.
-       __ str(dst, Address(rthread, JavaThread::gclab_top_offset()));
-       if (!c_abi) {
-         __ pop(saved, sp);
-       }
-       __ ret(lr);
- 
-       // Come here if the count of HeapWords is odd.
-       {
-         __ bind(odd_count);
-         __ ldr(rscratch1, __ post(src, HeapWordSize));
-         __ str(rscratch1, __ post(dst, HeapWordSize));
-         __ subs(size, size, HeapWordSize);
-         __ b(loop);
-       }
- 
-       // Come here if obj is an array of some kind.
-       {
-         __ bind(not_an_instance);
- 
-         // It's an array.  Calculate the size in r4.
-         __ ubfx(r4, size, Klass::_lh_header_size_shift,
-                 exact_log2(Klass::_lh_header_size_mask+1));
-         __ ldrw(rscratch1, Address(obj, arrayOopDesc::length_offset_in_bytes()));
-         __ ubfx(rscratch2, size, Klass::_lh_log2_element_size_shift,
-                 exact_log2(Klass::_lh_log2_element_size_mask+1));
-         __ lslv(rscratch1, rscratch1, rscratch2);
-         __ add(size, rscratch1, r4);
- 
-         // Round up the size.
-         __ add(size, size, MinObjAlignmentInBytes-1);
-         __ andr(size, size, -MinObjAlignmentInBytes);
- 
-         __ b(is_array);
-       }
- 
-       // Make a runtime call to evacuate the object.
-       __ bind(slow_case);
-       if (!c_abi) {
-           __ pop(saved, sp);
-       }
-     }
  
      __ enter(); // required for proper stackwalking of RuntimeStub frame
  
      if (!c_abi) {
        __ push_call_clobbered_registers();
--- 573,582 ----