From: Stephen Hemminger <[EMAIL PROTECTED]> Date: Mon, 5 Mar 2007 15:57:14 -0800
> I tried the code from Hacker's Delight. > It is cool, but performance is CPU (and data) dependent: > > Average # of usecs per operation: Interesting results. The problem with these algorithms that tradoff one or more multiplies in order to avoid a divide is that they don't give anything and often lose when both multiplies and divides are emulated in software. This is particularly true in this cube-root case from Hacker's Delight, because it's using 3 multiplies per iteration in place of one divide per iteration. Actually, sorry, there is only one real multiply in there since the other two can be computed using addition and shifts. Another thing is that the non-Hacker's Delight version iterates differently for different input values, so the input value space is very important to consider when comparing these two pieces of code. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
