src/cpu/x86/vm/assembler_x86_64.cpp

*** 5005,5016 ****
    andq(tmp_reg, markOopDesc::biased_lock_mask_in_place);
    cmpq(tmp_reg, markOopDesc::biased_lock_pattern);
    jcc(Assembler::notEqual, cas_label);
    // The bias pattern is present in the object's header. Need to check
    // whether the bias owner and the epoch are both still current.
!   load_klass(tmp_reg, obj_reg);
!   movq(tmp_reg, Address(tmp_reg, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
    orq(tmp_reg, r15_thread);
    xorq(tmp_reg, swap_reg);
    andq(tmp_reg, ~((int) markOopDesc::age_mask_in_place));
    if (counters != NULL) {
      cond_inc32(Assembler::zero,
--- 5005,5015 ----
    andq(tmp_reg, markOopDesc::biased_lock_mask_in_place);
    cmpq(tmp_reg, markOopDesc::biased_lock_pattern);
    jcc(Assembler::notEqual, cas_label);
    // The bias pattern is present in the object's header. Need to check
    // whether the bias owner and the epoch are both still current.
!   load_prototype_header(tmp_reg, obj_reg);
    orq(tmp_reg, r15_thread);
    xorq(tmp_reg, swap_reg);
    andq(tmp_reg, ~((int) markOopDesc::age_mask_in_place));
    if (counters != NULL) {
      cond_inc32(Assembler::zero,
*** 5080,5091 ****
    // bias in the current epoch. In other words, we allow transfer of
    // the bias from one thread to another directly in this situation.
    //
    // FIXME: due to a lack of registers we currently blow away the age
    // bits in this situation. Should attempt to preserve them.
!   load_klass(tmp_reg, obj_reg);
!   movq(tmp_reg, Address(tmp_reg, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
    orq(tmp_reg, r15_thread);
    if (os::is_MP()) {
      lock();
    }
    cmpxchgq(tmp_reg, Address(obj_reg, 0));
--- 5079,5089 ----
    // bias in the current epoch. In other words, we allow transfer of
    // the bias from one thread to another directly in this situation.
    //
    // FIXME: due to a lack of registers we currently blow away the age
    // bits in this situation. Should attempt to preserve them.
!   load_prototype_header(tmp_reg, obj_reg);
    orq(tmp_reg, r15_thread);
    if (os::is_MP()) {
      lock();
    }
    cmpxchgq(tmp_reg, Address(obj_reg, 0));
*** 5111,5122 ****
    // bias of this particular object, so it's okay to continue in the
    // normal locking code.
    //
    // FIXME: due to a lack of registers we currently blow away the age
    // bits in this situation. Should attempt to preserve them.
!   load_klass(tmp_reg, obj_reg);
!   movq(tmp_reg, Address(tmp_reg, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
    if (os::is_MP()) {
      lock();
    }
    cmpxchgq(tmp_reg, Address(obj_reg, 0));
    // Fall through to the normal CAS-based lock, because no matter what
--- 5109,5119 ----
    // bias of this particular object, so it's okay to continue in the
    // normal locking code.
    //
    // FIXME: due to a lack of registers we currently blow away the age
    // bits in this situation. Should attempt to preserve them.
!   load_prototype_header(tmp_reg, obj_reg);
    if (os::is_MP()) {
      lock();
    }
    cmpxchgq(tmp_reg, Address(obj_reg, 0));
    // Fall through to the normal CAS-based lock, because no matter what
*** 5155,5164 ****
--- 5152,5171 ----
      decode_heap_oop_not_null(dst);
    } else {
      movq(dst, Address(src, oopDesc::klass_offset_in_bytes()));
    }
  }
+ 
+ void MacroAssembler::load_prototype_header(Register dst, Register src) {
+   if (UseCompressedOops) {
+     movl(dst, Address(src, oopDesc::klass_offset_in_bytes()));
+     movq(dst, Address(r12_heapbase, dst, Address::times_8, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
+   } else {
+     movq(dst, Address(src, oopDesc::klass_offset_in_bytes()));
+     movq(dst, Address(dst, Klass::prototype_header_offset_in_bytes() + klassOopDesc::klass_part_offset_in_bytes()));
+   }
+ }
  
  void MacroAssembler::store_klass(Register dst, Register src) {
    if (UseCompressedOops) {
      encode_heap_oop_not_null(src);
      movl(Address(dst, oopDesc::klass_offset_in_bytes()), src);