MCS 572 Individual Cray C90 Starter Problem   Fall 1996

Professor F. B. HANSON


DUE Wednesday 25 Nov 1996 in class (this is individual, not group, homework)

Optimize the code

on the PSC Cray C90 by doing whatever is necessary to get the best performance, provided that all variables have the same final storage values in the optimized code as the original code, WITHIN REASON, WITHOUT MULTITASKING, and no work is taken out of the original timing loop, such as using new data or parameter statement statements. A copy of this code can be found In particular, use the timer 'second' in the code with the optimizing Cray Fortran compile-link command: (your compiler information listing should result in `start.l') and execute as in order to report Be sure to label all above items for identification. Try to remove as many of the Cray Fortran (cf77) compiler non-optimized informational messages as possible, maximally use Fortran 90 array extensions, and use compiler directives only where needed. However, the FINAL storage into scalar variables and arrays must be the same as the original code. The best way to start is to temporarily put timers around all the loops, in order to find the most time consuming loop and work down to the smaller loops. Your final times should be the difference between the end of the code and the beginning of the code, less timer overhead, as in the original code.

Try to make the code fit the Cray vector model. Your performance will be inversely related to your total time in the new tuned optimized part of your program, if correct.


Notes:
Please report to Professor Hanson any problems:
Web Source:http://www.math.uic.edu/~hanson/c90start.html