src/hotspot/cpu/x86/x86_64.ad

*** 4368,15 ***
    match(Set dst (LoadNKlass mem));
    effect(KILL cr);
    ins_cost(125); // XXX
    format %{
      "movl    $dst, $mem\t# compressed klass ptr, shifted\n\t"
!     "shrl    $dst, markWord::klass_shift_at_offset"
    %}
    ins_encode %{
!     __ movl($dst$$Register, $mem$$Address);
!     __ shrl($dst$$Register, markWord::klass_shift_at_offset);
    %}
    ins_pipe(ialu_reg_mem); // XXX
  %}
  
  // Load Float
--- 4368,20 ---
    match(Set dst (LoadNKlass mem));
    effect(KILL cr);
    ins_cost(125); // XXX
    format %{
      "movl    $dst, $mem\t# compressed klass ptr, shifted\n\t"
!     "shrl    $dst, markWord::klass_shift"
    %}
    ins_encode %{
!     // The incoming address is pointing into obj-start + klass_offset_in_bytes. We need to extract
!     // obj-start, so that we can load from the object's mark-word instead. Usually the address
+     // comes as obj-start in obj and klass_offset_in_bytes in disp.
+     Register d = $dst$$Register;
+     Address  s = $mem$$Address;
+     __ movl(d, s.plus_disp(-Type::klass_offset()));
+     __ shrl(d, markWord::klass_shift);
    %}
    ins_pipe(ialu_reg_mem); // XXX
  %}
  
  // Load Float