Thomas Fischbacher <[EMAIL PROTECTED]> writes:
> On Tue, 14 Dec 2004, Harvey J. Stein wrote:
>
> > The compiler won't unbox the result of (one-normal-rand) and
> > (callpay), and I still don't know why.
>
> Hm, first of all, I suppose you should get lots of
>
> Unable to optimize due to type uncertainty
>
> compiler notes. If so, you should provide the compiler with the
> proper additional type information. Macros will help. Besides this, you
> may think of making one-normal-rand
>
>
> (defun one-normal-rand ()
> (declare (values (double-float)))
> (labels ((onr ()
> (let* ((u (random 1d0))
> (u1 (random 1d0)))
> (declare (type (double-float (0d0) 1d0) u u1))
> (let* ((v (* SQRT2OVERE (- (* 2d0 u1) 1d0)))
> (x (/ v u))
> (y (/ (* x x) 4d0)))
> (if (and (> y (- 1d0 u))
> (> y (- (log u))))
> (onr)
> x)))))
> (onr)))
>
> so that you can let the compiler inline it. And besides that, there
> furthermore would be block compilation.
When I compile this snippet, preceeded by:
(eval-when (compile)
(proclaim '(optimize (speed 3) (safety 1) (space 0) (debug 0))))
(defconstant SQRT2OVERE (the double-float (sqrt (/ 2d0 (exp 1d0)))))
(eval-when (compile)
(proclaim '(type double-float SQRT2OVERE)))
I get a compilation note:
* (compile-file "bsmc-cl-t2")
Python version 1.0, VM version Intel x86 on 14 DEC 04 01:38:37 pm.
Compiling: /home/hjstein/Quadrus/bsmc-cl-t2.lisp 14 DEC 04 01:38:35 pm
Converted ONE-NORMAL-RAND.
Compiling DEFUN ONE-NORMAL-RAND:
File: /home/hjstein/Quadrus/bsmc-cl-t2.lisp
In: DEFUN ONE-NORMAL-RAND
(DEFUN ONE-NORMAL-RAND ()
(DECLARE (VALUES #))
(LABELS (#)
(ONR)))
Note: Doing float to pointer coercion (cost 13) to "<return value>".
I don't know if this is faster or not, but it doesn't clear up the
cost 13 coercion to pointer note. BTW, neither does replacing the
recursion with iteration. And, using inlining & block compilation
doesn't help much either.
--
Harvey Stein
Bloomberg LP
[EMAIL PROTECTED]
