Re: Pure nil and t?

[David Kastrup <dak@gnu.org>]

Dmitry Antipov <dmantipov@yandex.ru> writes:

> For a long byte-compile runs, ~15-17% of objects seen by GC are nil and t
> (especially nil, which is ~10x more "popular" than t).  What about making
> them pure?  Thus way they will be quickly filtered out by PURE_POINTER_P
> check in mark_object, thus offloading GC from an in-depth examination of
> them each time when they're found.

In my Emacs I see
M-: (symbol-plist nil) RET
(event-symbol-element-mask (nil 0) event-symbol-elements (nil) modifier-cache ((0)))
M-: (symbol-plist t) RET
(event-symbol-element-mask (t 0) event-symbol-elements (t) modifier-cache ((0 . t)))

While I consider it likely that those are the result of glitches and/or
bugs, it would be nice if those glitches did not lead to crashes by
letting these plists get collected in spite of being accessible.

I have no idea whether this would be the case.  It's just that I can
imagine it to be.

-- 
David Kastrup