Programming Parallel Computers

Open 2024b

CP2a: instruction-level parallelism ★

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What you will need to do in this task

Please read the general instructions for this exercise first. Here are the additional instructions specific to this task:

Parallelize your solution to CP1 by exploiting instruction-level parallelism. Make sure that the performance-critical operations are pipelined efficiently. Do not use any other form of parallelism yet in this exercise. Please do all arithmetic with double-precision floating point numbers.

For this technical exercise, we have disabled auto-vectorization.

What I will try to do with your code

I will first run all kinds of tests to see that your code works correctly. You can try it out locally by running ./grading test, but please note that your code has to compile and work correctly not only on your own computer but also on our machines.

If all is fine, I will run the benchmarks. You can try it out on your own computer by running ./grading benchmark, but of course the precise running time on your own computer might be different from the performance on our grading hardware.

Benchmarks

Name Parameters
benchmarks/1 nx = 1000, ny = 1000
the input contains 1000 × 1000 pixels, and the output should contain 1000 × 1000 pixels
benchmarks/2 nx = 1000, ny = 4000
the input contains 4000 × 1000 pixels, and the output should contain 4000 × 4000 pixels

Grading

In this task your submission will be graded using benchmarks/2: the input contains 4000 × 1000 pixels, and the output should contain 4000 × 4000 pixels.

The point thresholds are as follows. If you submit your solution no later than on Wednesday, 31 July 2024, at 23:59:59 (Helsinki), your score will be:

Running timePoints
≤ 7.000 sec 1
≤ 6.000 sec 2
≤ 5.000 sec 3

If you submit your solution after the deadline, but before the course ends on Wednesday, 28 August 2024, at 23:59:59 (Helsinki), your score will be:

Running timePoints
≤ 6.000 sec 1
≤ 5.000 sec 2