At Tue, 25 Feb 2014 09:22:54 -0500, Sam Tobin-Hochstadt wrote:
> On Tue, Feb 25, 2014 at 8:34 AM, <mfl...@racket-lang.org> wrote:
> >
> > eff53cd Matthew Flatt <mfl...@racket-lang.org> 2014-02-24 16:42
> > :
> > | treat FFI primitives like other primitives internally
> > |
> > | This change paves the way for JIT-inlining FFI operations
> > | such as `ptr-ref`. Even without JIT treatment, the change
> > | slightly reduces the overhead for calling FFI primitives.
>
> Do you have benchmarks for the FFI that you used here?
The claim of reduced overhead was based on removing indirections
through scheme_do_eval(), as visible in a low-level profile of a
drawing loop.
Now that you ask, though, the change cuts about 25% of the time for the
loop below on my machine.
----------------------------------------
#lang racket/base
(require ffi/unsafe)
(define N 1000)
(define p (malloc N))
(time
(for ([i (in-range 1000)])
(for ([j (in-range N)])
(ptr-set! p _byte j 42))))
_________________________
Racket Developers list:
http://lists.racket-lang.org/dev
