Lecture 11

Learning objectives

After this class, you should be able to:

1. Define the reduction operation.
2. Define the term work-efficient.
3. Analyze the time complexity of parallel reduction and explain the reason for branch divergence.

Reading assignment

1. Read UIUC Lecture 11 slides.
2. Chapter 6 of text, section 6.1.

Exercises and review questions

• Exercises and review questions on current lecture's material
  1. Consider the parallel reduction algorithm discussed in class. Is commutativity of the operator required for correctness of the algorithm?
  2. How can the reduction algorithm be modified for the situation where the number of threads is much smaller than the number of data items that need to be reduced?

• Preparation for the next lecture
  1. None.

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Last modified: 12 Feb 2013