Loop perforation

Loop perforation is an approximate computing technique that allows to regularly skip some iterations of a loop.^[1]

It relies on one parameter: the skip factor. The skip factor can either be interpreted as the number of iteration to skip each time or the number of iterations to perform before skipping one.

Code examples

The examples that follows provide the result of loop perforation applied on this C-like source code

for ( int i = 0; i < N; i++ ) {
     // do things
 }

Skip n iterations each time

for ( int i = 0; i < N; i++ ) {
     // do things
     i = i + skip_factor;
 }

Skip one iteration after n

int count = 0;
 for ( int i = 0; i < N; i++ ) {
     if (count == skip_factor) {
         count = 0;
     } else {
         // do things
         count ++;
     }
 }

See also

• Approximate computing
• Task skipping
• Memoization

References

1. Mittal, Sparsh (May 2016). "A Survey of Techniques for Approximate Computing". ACM Comput. Surv. ACM. 48 (4): 62:1–62:33. doi:10.1145/2893356.