3 ms·
No, the order in which things happen would be different, and this is what might make it more cache-efficient for rotating large images. It should look like this
by gsliepen 5y ago
No, the order in which things happen would be different, and this is what might make it more cache-efficient for rotating large images. It should look like this: https://en.wikipedia.org/wiki/Z-order_curve https://en.wikipedia.org/wiki/Z-order_curve
- dan-robertson 5y agoI’m really confused by what you mean. If you’re not executing the line I wrote above (in parallel) then what are you doing? The things I could think you meant were: - moving data in stages like the OP video which might be better for the cache (I don’t believe this) but would require writing to/from me more multiple times per pixel which I think would make it slower - Accessing memory in a certain order when doing this on a cpu. Certainly that is a reasonable thing to expect to improve performance (roughly breaking the image into blocks that fit exactly into N cache lines, rotating in registers/memory, then writing into exactly N cache lines means you aren’t reading data from RAM/cache that you can’t use), but I don’t think that is related to the recursive process described in the article, unless you mean that you can use this process to get some operations like block(x,y,16) moves to block(s,t,16) and those could be executed cache-efficiently? But then this recursive method is more confusing and more restrictive on the image size than the thing I tried to describe at the start of this bullet point