Re: memove performance of NetBSD

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Thu, Jan 28, 2010 at 11:08:16AM +0530, Channa wrote:
> 
> I verified the current implementation , the copy operation or move
> operation is done word by word.
> 
> I have modified the algorithm as below:
> <1> Align the source if not aligned by copying only few bytes to destination
> <2> Copy 4 words at a time.
> 
> I verified the modification with the performance of memmove for
> aligned and unaligned combination, the performance does not degrade
> for unaligned access.

Does the performance actually improve in any case?  If so, does it still
improve if you remove the hand-unrolling of the loop?

I'm shocked that the compiler can't unroll the loop by 4 for you.

Thor