Computer Science > QUESTIONS & ANSWERS > University of California, BerkeleyCS 61C61chw10. (All)

University of California, BerkeleyCS 61C61chw10.

Document Content and Description Below

Q1 Parallelism Principles 7 Points The Hamming distance between two bitstrings of equal length is the number of locations in which the bits differ. For example, hamming(0b1011101, 0b1001001) == 2 ... . Consider the following Hamming distance code: uint32_t hamming(uint32_t x, uint32_t y) { uint32_t mask, ham_dist = 0; #pragma omp for for (int i = 0; i <= 31; i++) { mask = 1 << i; if ((y & mask) != (x & mask)) { ham_dist++; } } return ham_dist; } Q1.1 Shared/Private Variables 4 Points For each variable below, decide whether it SHOULD be "shared" or "private" among threads. Do not mark a variable as private if it can be safely shared. x y mask  shared  private  shared  private9/11/2020 View Submission | Gradescope https://www.gradescope.com/courses/92697/assignments/512318/submissions/40847486 2/24 i Q 1.2 Data Race 2 Points Is a data race on ham_dist possible? Make sure you can explain why or why not. If yes, think about how to fix the code. Based on your answer above, which variables could be incorrect as a result of the data race? Q1.3 False Sharing 1 Point  shared  private  shared  private  Yes  No x y m ask i h  am_dist None of the above. There was no data race. [Show More]

Last updated: 3 years ago

Preview 1 out of 24 pages

Buy Now

Instant download

We Accept: