SUM_MILLION
A Program to Sum the Numbers from 1 to 1,000,000

SUM_MILLION is intended to be a program that sums the numbers from 1 to 1,000,000, prints the result, the elapsed CPU time, and the corresponding MegaFLOPS rate.

This directory contains only partial programs - they are just sketches of the code, and you will need to supply the details for the missing code.

Assignment:

Choose a partial program in your favorite language.

• finish the program so that it assigns the numbers 1 to 1,000,000 to the array X, then sums the entries of X, and prints the sum.
• add timing calls so that you can determine the CPU time for the addition loop, and the MegaFLOPS rate.
• See if you can improve the MegaFlops rate by doing the loop in steps of 4 at a time. That is, the loop index increments by 4, and the summation line looks something like

  total = total + x(i) + x(i+1) + x(i+2) + x(i+3)

Source Code:

• sum_million.c, the C source code.
• sum_million.cc, the C++ source code.
• sum_million.f, the FORTRAN77 source code.
• sum_million.f90, the FORTRAN90 source code.

You can go up one level to the HPPC 2008 web page.