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← Segmented Scan - Intro to Parallel Programming

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Showing Revision 4 created 05/25/2016 by Udacity Robot.

  1. Okay, so this is pretty straightforward.
  2. The output at any particular element is the sum of that element
  3. and all elements that come before it in the current segment.
  4. But we're starting it over at every segment boundary.
  5. So 12, for instance, is the sum of 3, 4, and 5 but nothing from the previous segment.
  6. We're not going to go through how this is implemented,
  7. but it's a terrific exercise to work out on your own,
  8. whether you do it with Hillis and Steele scan or the Blelloch scan.
  9. It has the same complexity as unsegmented scan, but it runs a little slower
  10. because you have to keep track of the segments along the way.
  11. So it requires more memory traffic as well as more complex computation.
  12. We'll have to put a little more information about the implementation of segmented scan
  13. in the supplementary materials.
  14. But again, this is a really great problem for you to work out on your own.