POV-Ray : Newsgroups : povray.general : Requesting ideas/opinions for RNG seeding syntax : Re: Requesting ideas/opinions for RNG seeding syntax Server Time
30 Jul 2024 22:16:51 EDT (-0400)
  Re: Requesting ideas/opinions for RNG seeding syntax  
From: "Jérôme M. Berger"
Date: 24 May 2009 03:18:33
Message: <4a18f4c9$1@news.povray.org>

>  > g++ -O3 -lm -o random random.cc IsaacRand.cc
> 
>  > ./random
> Empty loop:          0ms
> Kiss64 (int):     6623ms
> Kiss64 (dbl):     5003ms
> Alvo (floor):    21539ms
> Alvo (cast):     14608ms
> Alvo (tmp+cast): 14664ms
> Isaac:           10540ms
> 
	Upon reflection, those timing are ridiculous because there is no 
way to know what was optimized away by the compiler (like the empty 
loop: no matter how high I set LOOPS, that takes 0ms which is 
absurd). So here are the timings with no optimization (-O0):

Empty loop:       6324ms
Kiss64 (int):    13482ms
Kiss64 (dbl):    33679ms
Alvo (floor):    26223ms
Alvo (cast):     20113ms
Alvo (tmp+cast): 23512ms
Isaac:           33855ms

	Of course, this doesn't say anything about the quality of the 
random numbers generated.

		Jerome
-- 
mailto:jeb### [at] freefr
http://jeberger.free.fr
Jabber: jeb### [at] jabberfr


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