Function
hcl
clean-down &optional free-upper => new-size
:free-upper controls whether the empty segments of the highest generation are removed or not. The default ist. The new size of the image, after reduction.
mark-and-sweep on generation 3, promotes all the objects into generation 3, deletes the empty segments and tries to reduce the image size. It may fail to delete empty segments if there are static segments in high address space.