Allocation

This example test different ways to allocate an array of integer from 0 to n. Four different implementations are tested:

Preallocation

allocate(array(n))
do i = 1, n
    array(i) = i
end do

Array contructor

array = [(i, i = 1,n)]

Dynamic reallocation

allocate(array(0))
do i = 1, n
    array = [array, i]
end do

And a method using buffers based on the following example

The results are as follows:

Method Name	Mean	Standard Deviation
array_preallocation(50000)	114.112 us	+/- 5.940 us
array_preallocation(100000)	220.971 us	+/- 6.818 us
array_constructor(50000)	99.854 us	+/- 4.982 us
array_constructor(100000)	192.367 us	+/- 2.191 us
naive_reallocation(50000)	3.483 s	+/- 0.227 s
naive_reallocation(100000)	13.755 s	+/- 1.131 s
buffer_reallocation(100,50000)	8.004 ms	+/- 0.170 ms
buffer_reallocation(100,100000)	30.195 ms	+/- 0.631 ms
buffer_reallocation(1000,50000)	1.302 ms	+/- 0.029 ms
buffer_reallocation(1000,100000)	4.468 us	+/- 0.059 ms