Examples of Loop Counts

A few examples of different loops,

1. upper bound not exact,

       loopy: DO i = 1, 30, 2  
        ... ! i is 1,3,5,7,...,29
        ... ! 15 iterations
       END DO loopy

2. negative stride,

       DO j = 30, 1, -2 
        ... ! j is 30,28,26,...,2
        ... ! 15 iterations
       END DO

3. a zero-trip loop,

       DO k = 30, 1, 2  
        ... ! 0 iterations
        ... ! loop skipped
       END DO

4. missing stride -- assume it is 1,

       DO l = 1,30
        ... ! i = 1,2,3,...,30
        ... ! 30 iterations
       END DO

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