src/hotspot/cpu/x86/templateTable_x86.cpp

@@ -4083,12 +4083,11 @@
      }
  
      // The object is initialized before the header.  If the object size is
      // zero, go directly to the header initialization.
      if (UseCompactObjectHeaders) {
-       assert(is_aligned(oopDesc::base_offset_in_bytes(), BytesPerLong), "oop base offset must be 8-byte-aligned");
-       __ decrement(rdx, oopDesc::base_offset_in_bytes());
+       __ decrement(rdx, align_up(oopDesc::base_offset_in_bytes(), BytesPerLong));
      } else {
        __ decrement(rdx, sizeof(oopDesc));
      }
      __ jcc(Assembler::zero, initialize_header);