Felician Nemeth <felician.nemeth@gmail.com> writes:

> (disassemble (byte-compile '(append '(1 2) '(3 4))))
>
> resuts in
>
> byte code:
>   args: nil
> 0	constant  append
> 1	constant  (1 2)
> 2	constant  (3 4)
> 3	call	  2
> 4	return	  
>
> Instead I expected it to be something like
>
> byte code:
>   args: nil
> 0	constant  1
> 1	constant  2
> 2	constant  3
> 3	constant  4
> 4	list4	  
> 5	return	  
>
> I've never looked at byte-code optimization before, and I'm guessing
> this is not a huge improvement, but I still wonder when all the
> arguments of side-effect-free function are constants would it make sense
> to calculate the result at compile time.

`byte-optimize-append' mentions:

  ;; There is (probably) too much code relying on `append' to return a
  ;; new list for us to do full constant-folding; these transformations
  ;; preserve the allocation semantics.

I am not sure what the danger is in the case of constant, quoted lists,
but I am not familiar with the byte compiler either.  It seems like this