Inline Expansion

This would reduce execution time because of less function lookups, but returns messy code.

cubed <- function(x) {
  x * x * x
}

f <- function(n) {
  to_cubes <- 0;
  for (i in seq_len(n)) {
    to_cubes <- to_cubes + cubed(i) # function call (cubed)
  }
}

f_opt <- function(n) {
  to_cubes <- 0;
  for (i in seq_len(n)) {
    to_cubes <- to_cubes + (i * i * i) # function inlined
  }
}

f_c <- cmpfun(f)
f_opt_c <- cmpfun(f_opt)

n <- 1000
autoplot(microbenchmark(f(n), f_c(n), f_opt(n), f_opt_c(n)))