[plt-scheme] Integer-length

From: Jens Axel Søgaard (jensaxel at soegaard.net)
Date: Wed Mar 22 17:09:41 EST 2006

Matthew Flatt wrote:

> Out of curiosity, did you measure with the JIT and other recent
> improvements?

Not yet. I used DrScheme without debugging or profiling.

> I changed Joe's code to use `quotient' in place of `floor->exact' with
> '/'. In 301.11 (with the JIT enabled), then Joe's seems faster for
> small numbers, and only slightly slower for numbers around 1000000. For
> numbers like 2^30, Joe's is around 4 times slower. For very large
> numbers like 2^300000, Joe's is much better.
> 
> Of course, I agree that MzScheme should probably provide something like
> `integer-length' based on the internal representation of numbers.

I found some interesting tricks for the fixnum range here:

<http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogObvious>

-- 
Jens Axel Søgaard





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