From: Robert Klemme <shortcutter@...>
Date: 2008-03-30T02:40:07+09:00
Subject: Re: Why Ruby do not optimize code at all?

On 29.03.2008 18:03, s.ross wrote:
> On Mar 29, 2008, at 9:50 AM, Robert Klemme wrote:
> 
>> On 28.03.2008 18:21, s.ross wrote:
>>
>>> Before this question is relegated to the heap of "premature   
>>> optimization" ideas, I think the value of some level of programmer-  
>>> controller optimizations would be useful in the future.
>> I guess you mean "programmer controlled", did you?  In fact, there  
>> is plenty of room for that today already.  There are numerous  
>> techniques that can be applied to code to make it faster.  Often,  
>> proper design and / or algorithms make a huge difference. :-)
> 
> Yes, "controlled". And yes, a good algo beats a machine optimization  
> almost every time. But still, some of the stupid optimization tricks  
> people have traditionally used for the last several percent destroy  
> the readability of code. I've never been terribly unhappy with the  
> performance of Ruby, but if I were ... say ... Industrial Light and  
> Magic and choosing between Ruby and Python to glue my effects stuff  
> together, I might be swayed toward Python because it preserves  
> bytecode (right?).

I am not sure what you mean by "preserve bytecode".

> It might be nice, once we figure out how to express  
> Ruby in an optimizable bytecode to create JIT optimizers that are  
> platform specific. Who knows what results that might yield.

There is JRuby already.  IMHO this is a good way to go because a lot of 
engineering went into JVM's already and that way Ruby can benefit from 
that without having to invest the same effort into the VM.

> My original point, spelling not withstanding, is that this is a topic  
> (along with threading) that typically gets relegated to the premature  
> optimizations bin, and doesn't rise to the level of "this should be  
> possible one day and it should work with only the predictable  
> glitches." If I were heavily invested in my Java or C programming  
> skills, and wanted to keep Ruby out of my shop -- and there are people  
> who do fight to keep new technologies away -- lack of optimization  
> might be an attack plan.

I guess even with such optimizations Ruby will never come close in 
performance to C and maybe even not to Java because of the highly 
dynamic nature.  OTOH, if explicit enabling of certain optimizations 
disables some of the dynamic features that might be ok...

> Again, just my opinion.

No problem with that.  I just wanted to make the half serious point that 
there *is* indeed a lot of room for programmer controlled optimization 
that does not need -O3. :-)

Kind regards

	robert