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Date: Mon, 25 Jul 2005 20:23:17 +0100
From: Paulo Marques <pmarques@grupopie.com>
Organization: Grupo PIE
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To: Lee Revell <rlrevell@joe-job.com>
Cc: Steven Rostedt <rostedt@goodmis.org>, Bernd Petrovitsch <bernd@firmix.at>,
       Andrew Morton <akpm@osdl.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Grant Coady <lkml@dodo.com.au>,
       Jan Engelhardt <jengelh@linux01.gwdg.de>,
       Puneet Vyas <vyas.puneet@gmail.com>
Subject: Re: xor as a lazy comparison
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Lee Revell wrote:
> On Mon, 2005-07-25 at 13:55 -0400, Steven Rostedt wrote: 
> 
>>Doesn't matter. The cycles saved for old compilers is not rational to
>>have obfuscated code.
> 
> Where do we draw the line with this?  Is x *= 2 preferable to x <<= 2 as
> well?

I guess this depends on what you logically want to do. If the problem 
requires you to shift some value N bits, then you should use a shift 
operation.

If what you want is to multiply a value by a certain ammount, you should 
just use a multiplication.

Using a shift to perform the multiplication should be left to the 
compiler IMHO.

The proof that the shift is not so clear is that even you got the shift 
wrong in your own example ;)

-- 
Paulo Marques - www.grupopie.com

It is a mistake to think you can solve any major problems
just with potatoes.
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