Re: Compilation to native

[Matthew Mundell]

Richard Stallman <address@hidden> writes:

>     There is the possibility of further improvement, especially for this
>     example, by moving Lisp object referencing and setting out of loops.
>     This will surely be tricky, though, if only because the functions
>     called by the byte code operations could change these objects.
>
> Maybe optimize the bytecode instead.

This seems to be very much like the second item on the byte-opt.el TO
DO list.  The item is as follows.


;; maintain a list of functions known not to access any global variables
;; (actually, give them a 'dynamically-safe property) and then
;;   (let ( v1 v2 ... vM vN ) <...dynamically-safe...> )  ==>
;;   (let ( v1 v2 ... vM ) vN <...dynamically-safe...> )
;; by recursing on this, we might be able to eliminate the entire let.
;; However certain variables should never have their bindings optimized
;; away, because they affect everything.
;;   (put 'debug-on-error 'binding-is-magic t)
;;   (put 'debug-on-abort 'binding-is-magic t)
;;   (put 'debug-on-next-call 'binding-is-magic t)
;;   (put 'inhibit-quit 'binding-is-magic t)
;;   (put 'quit-flag 'binding-is-magic t)
;;   (put 't 'binding-is-magic t)
;;   (put 'nil 'binding-is-magic t)
;; possibly also
;;   (put 'gc-cons-threshold 'binding-is-magic t)
;;   (put 'track-mouse 'binding-is-magic t)
;; others?