On Tue, 5 Apr 2011 15:37:47 +0100, Mike Kerford-Byrnes <m...@hill-leys.com> wrote:
> >Of late, I have been instinctively inserting a 256-byte "filler" between the >last instruction and the LTORG. In my test environment it makes not a jot >of difference, but on the big boxes.. Well it does no harm. > Yes, that is a good idea, although it would be nice if the Assembler made it easier to put things on 256-byte boundaries. Once you've gotten something into cache, the cost of referencing or updating it is trivial; its the cost of getting it into the cache in the first place that takes its toll, so the goal should be to get what you want into the cache in as few references as possible. In general, avoid searches as much as possible. If you have to search, use data structures that subdivide the search space as rapidly (touching as few things) as possible. Trees and tries are better than lists, and hashes - if you can use them - are even better. W. Kevin Kelley -- IBM POK Lab -- z/OS Core Technical Development
