Re: [Chicken-hackers] code suggestion

[Jörg F . Wittenberger]

Sure I had to forget the attachment.

In the meantime I tried the last thought and it worked.  Even less code now:

void C_ccall C_make_vector(C_word c, C_word *av)
{
  C_word av2[2], *v=av+1;
  av2[0] = av[1];
  *v = C_VECTOR_TYPE | (c-2);
  av2[1] = (C_word) v;
  C_do_apply(2, av2);
}

(define vector (##core#primitive "C_make_vector"))

This time with test attached.

Cheers

/Jörg

Am 01.02.2016 um 19:27 schrieb Jörg F. Wittenberger:
> Hi all,
> 
> given argvector's in place I wonder if we should change some things.
> 
> If this code would be correct.  If so, it could simplify library.scm
> (list->vector and vector->list would become one-liners, vector a
> ##core#primitive) and save runtime.
....
> -------
> 
> we could rewrite dynamic-wind like this:
> 
> --- library.scm ---
> (define (dynamic-wind before thunk after)
>   (before)
>   (set! ##sys#dynamic-winds (cons (cons before after) ##sys#dynamic-winds))
>   (let ((results (##sys#call-with-values thunk vector)))
>     (set! ##sys#dynamic-winds (##sys#slot ##sys#dynamic-winds 1))
>     (after)
>     (apply-vector/unsafe ##sys#values results)))
> -------
> 
> The attached test does some simple benchmarking on this.  Depending on
> optimization (-O2 or more) results on my desktop machine indicate
> anything between 10-30% gain.
> 
> Having written this, I wonder: maybe we could simply put the tag into
> av[1] in the C_make_vector above and return av+1.  Should have the same
> effect and save all the memcpy.
> 
> Cheers
> 
> /Jörg

multivalencapts.scm
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