[paraboul]

Pointers are fixed size (either 32 or 64bits). When a project got bigger, it's sometimes useful to "shrink" the number of pointers you're passing around.

Nicholas Nethercote has a blog about his work on this on Firefox : https://blog.mozilla.org/nnethercote/ (e.g. https://blog.mozilla.org/nnethercote/2011/11/01/spidermonkey...)