AllocsPerRun returns the average number of allocations during calls to f. Although the return value has type float64, it will always be an integral value.

To compute the number of allocations, the function will first be run once as a warm-up. The average number of allocations over the specified number of runs will then be measured and returned.

AllocsPerRun sets GOMAXPROCS to 1 during its measurement and will restore it before returning.