[plt-scheme] Integer-length

Matthew Flatt wrote:
> At Wed, 22 Mar 2006 22:58:33 +0100, Jens Axel Søgaard wrote:
> 
>>It would be interesting to hear the timings on the JIT version.
> 
> 
> Four sets of times are below:
> 
>  1. In a module, JIT enabled
>  2. In a module, JIT disabled
>  3. As a top-level program, JIT enabled
>  4. As a top-level program, JIT disabled
> 
> To the last one roughly corresponds to your run, but on my machine.
> 
> MzScheme 301.11, x86, Windows.
> 
> Matthew
> 
> ----------------------------------------
> BIG-TEST
> joe
> cpu time: 1718 real time: 1750 gc time: 891
> jens-axel
> cpu time: 250 real time: 250 gc time: 0
> jacob
> cpu time: 766 real time: 781 gc time: 344
> robby
> cpu time: 734 real time: 734 gc time: 312

> SMALL-TEST-100
> joe
> cpu time: 750 real time: 750 gc time: 389
> jens-axel
> cpu time: 94 real time: 94 gc time: 0
> jacob
> cpu time: 782 real time: 782 gc time: 359
> robby

Since 1. will the "normal" situation, perhaps this
will be better for these tests?

(define (integer-length n)
   (if (<= n 65535)
       (if (<= n 255)
           (if (<= n 15)
               (if (<= n 3)
                   (if (<= n 1)
                       1
                       2)
                   (if (<= n 7)
                       3
                       4))
               (if (<= n 63)
                   (if (<= n 31)
                       5
                       6)
                   (if (<= n 127)
                       7
                       8)))
           (if (<= n 4095)
               (if (<= n 1023)
                   (if (<= n 511)
                       9
                       10)
                   (if (<= n 2047)
                       11
                       12))
               (if (<= n 16383)
                   (if (<= n 8191)
                       13
                       14)
                   (if (<= n 32767)
                       15
                       16))))
       (jens-axel n)))
(define robby2 integer-length)


-- 
Jens Axel Søgaard