data-representation changes of 2.7.x stable. Version 2.8 exploits the changes of of 2.7 to support 64-bit processors like the DEC Alpha. As of version 2.8.5, the representation of recorded the terms has changed, and terms on the heap are now represented in a compiled format. SWI-Prolog no longer limits the use of malloc() or uses assumptions on the addresses returned by this function.