| #![feature(test)] |
| |
| extern crate test; |
| extern crate itertools; |
| |
| use test::{black_box, Bencher}; |
| use itertools::Itertools; |
| |
| // approximate 100_000 iterations for each combination |
| const N1: usize = 100_000; |
| const N2: usize = 448; |
| const N3: usize = 86; |
| const N4: usize = 41; |
| |
| #[bench] |
| fn comb_for1(b: &mut Bencher) { |
| b.iter(|| { |
| for i in 0..N1 { |
| black_box(i); |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_for2(b: &mut Bencher) { |
| b.iter(|| { |
| for i in 0..N2 { |
| for j in (i + 1)..N2 { |
| black_box(i + j); |
| } |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_for3(b: &mut Bencher) { |
| b.iter(|| { |
| for i in 0..N3 { |
| for j in (i + 1)..N3 { |
| for k in (j + 1)..N3 { |
| black_box(i + j + k); |
| } |
| } |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_for4(b: &mut Bencher) { |
| b.iter(|| { |
| for i in 0..N4 { |
| for j in (i + 1)..N4 { |
| for k in (j + 1)..N4 { |
| for l in (k + 1)..N4 { |
| black_box(i + j + k + l); |
| } |
| } |
| } |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_c1(b: &mut Bencher) { |
| b.iter(|| { |
| for (i,) in (0..N1).tuple_combinations() { |
| black_box(i); |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_c2(b: &mut Bencher) { |
| b.iter(|| { |
| for (i, j) in (0..N2).tuple_combinations() { |
| black_box(i + j); |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_c3(b: &mut Bencher) { |
| b.iter(|| { |
| for (i, j, k) in (0..N3).tuple_combinations() { |
| black_box(i + j + k); |
| } |
| }); |
| } |
| |
| #[bench] |
| fn comb_c4(b: &mut Bencher) { |
| b.iter(|| { |
| for (i, j, k, l) in (0..N4).tuple_combinations() { |
| black_box(i + j + k + l); |
| } |
| }); |
| } |