src/hotspot/cpu/x86/sharedRuntime_x86_64.cpp

*** 2678,2687 ****
--- 2678,2691 ----
      // Load immediate 1 into swap_reg %rax
      __ movl(swap_reg, 1);
  
      // Load (object->mark() | 1) into swap_reg %rax
      __ orptr(swap_reg, Address(obj_reg, oopDesc::mark_offset_in_bytes()));
+     if (EnableValhalla && !UseBiasedLocking) {
+       // For slow path is_always_locked, using biased, which is never natural for !UseBiasLocking
+       __ andptr(swap_reg, ~markOopDesc::biased_lock_bit_in_place);
+     }
  
      // Save (object->mark() | 1) into BasicLock's displaced header
      __ movptr(Address(lock_reg, mark_word_offset), swap_reg);
  
      if (os::is_MP()) {