From: Peter Zotov <whitequark@...>
Date: 2012-07-03T09:27:10+09:00
Subject: Re: ruby performance

Dan Connelly писал 03.07.2012 04:06:
> I should provide version numbers... the RHEL on work machines is 
> pretty
> backwards.
>
> Ruby: 1.8.1
> Perl: 5.8.8

1.8.1?!! That's just ancient. I doubt it's compatible with any recent 
gems.
It seems that you need at least 1.8.6 even for the most compatible of 
them.

>
> I ran on my personal Macbook Air with Ruby 1.9.3 and Perl 5.10, and 
> Perl
> was only 2x faster.  So it seems Ruby 1.9 is indeed substantially 
> faster
> (assuming Perl is fairly stable).
>
> Curious when I did the loop in C how huge the speed increase was with
> -O1 versus -O0...
>
> #include <stdio.h>
> int main(void) {
>   int i = 0;
>   while (++i < 10000000);
>   printf("i = %d", i);
>   return 0;
> }
>
> but that's a bit off-topic...

I don't know your precise GCC version so I won't comment on any 
particular
optimization details my GCC version does, but I'd advise you to read 
the
relevant assembly. The change could be anything from binding `i' to
a register to pre-computing the entire loop (yeah, recent GCC can do 
that.)

-- 
   WBR, Peter Zotov.