CS475 Lab 5: Wavefront Parallelization
ObjectivesThis lab is intended to give you an hands-on experience on wave-front parallelization.
The objectives are
- To analyze and draw the data-dependencies in the given program.
- Redraw the dependence graph from the given iteration space to time and processor iteration space.
- Re-write the loop body for the transformed iteration space.
- Verify the functionality of your transformed program.
- Insert parallel pragmas for OpenMP parallelization of the transformed program.
- Measure the performance(speed-up on 1-8 processors) of the parallel code to that of the given code on State-capital machines.
Download the Lab5.tar file. It contains the following files.
Comment out the lines to compile the necessary files after performing wavefront-parallelization.
It is the same program as we saw in lecture. The sequential code is provided.
Complete the code for the transformation:
(i,j->p,t) = (i,j->i,i+j-1) by figuring out i,j in terms of p and t. In the given transformed code, t refers to the outer loop and p refers to the inner loop.
- timer.c and timer.h
Complete the code to perform Wavefront parallelization. In your lab report,
Last Modified: 9/27/2017
- Show the transformed loop body and dependences.
- Explain, how you compute the values for i,j in the trandformed code and why it is correct.
- Speed-up on 1-8 processors for N=200,2000,20000 on a state capital machine.