Break even point on my laptop appears to be around 16 bytes.
running 80 tests
test bench_cmp_0001_memcmp ... bench: 8 ns/iter (+/- 1) = 250 MB/s
test bench_cmp_0001_my_memcmp ... bench: 3 ns/iter (+/- 0) = 666 MB/s
test bench_cmp_0001_rust_cmp ... bench: 8 ns/iter (+/- 1) = 250 MB/s
test bench_cmp_0002_memcmp ... bench: 10 ns/iter (+/- 1) = 300 MB/s
test bench_cmp_0002_my_memcmp ... bench: 4 ns/iter (+/- 1) = 750 MB/s
test bench_cmp_0002_rust_cmp ... bench: 8 ns/iter (+/- 2) = 375 MB/s
test bench_cmp_0003_memcmp ... bench: 9 ns/iter (+/- 1) = 444 MB/s
test bench_cmp_0003_my_memcmp ... bench: 6 ns/iter (+/- 1) = 666 MB/s
test bench_cmp_0003_rust_cmp ... bench: 9 ns/iter (+/- 3) = 444 MB/s
test bench_cmp_0004_memcmp ... bench: 12 ns/iter (+/- 2) = 416 MB/s
test bench_cmp_0004_my_memcmp ... bench: 7 ns/iter (+/- 2) = 714 MB/s
test bench_cmp_0004_rust_cmp ... bench: 12 ns/iter (+/- 2) = 416 MB/s
test bench_cmp_0005_memcmp ... bench: 12 ns/iter (+/- 2) = 500 MB/s
test bench_cmp_0005_my_memcmp ... bench: 9 ns/iter (+/- 1) = 666 MB/s
test bench_cmp_0005_rust_cmp ... bench: 12 ns/iter (+/- 4) = 500 MB/s
test bench_cmp_0006_memcmp ... bench: 14 ns/iter (+/- 5) = 500 MB/s
test bench_cmp_0006_my_memcmp ... bench: 10 ns/iter (+/- 2) = 700 MB/s
test bench_cmp_0006_rust_cmp ... bench: 13 ns/iter (+/- 3) = 538 MB/s
test bench_cmp_0007_memcmp ... bench: 14 ns/iter (+/- 3) = 571 MB/s
test bench_cmp_0007_my_memcmp ... bench: 10 ns/iter (+/- 2) = 800 MB/s
test bench_cmp_0007_rust_cmp ... bench: 14 ns/iter (+/- 2) = 571 MB/s
test bench_cmp_0008_memcmp ... bench: 14 ns/iter (+/- 3) = 642 MB/s
test bench_cmp_0008_my_memcmp ... bench: 12 ns/iter (+/- 3) = 750 MB/s
test bench_cmp_0008_rust_cmp ... bench: 15 ns/iter (+/- 3) = 600 MB/s
test bench_cmp_0015_memcmp ... bench: 20 ns/iter (+/- 6) = 800 MB/s
test bench_cmp_0015_my_memcmp ... bench: 19 ns/iter (+/- 2) = 842 MB/s
test bench_cmp_0015_rust_cmp ... bench: 20 ns/iter (+/- 4) = 800 MB/s
test bench_cmp_0016_memcmp ... bench: 20 ns/iter (+/- 5) = 850 MB/s
test bench_cmp_0016_my_memcmp ... bench: 20 ns/iter (+/- 10) = 850 MB/s
test bench_cmp_0016_rust_cmp ... bench: 21 ns/iter (+/- 5) = 809 MB/s
test bench_cmp_0032_memcmp ... bench: 12 ns/iter (+/- 2) = 2750 MB/s
test bench_cmp_0032_my_memcmp ... bench: 40 ns/iter (+/- 5) = 825 MB/s
test bench_cmp_0032_rust_cmp ... bench: 12 ns/iter (+/- 2) = 2750 MB/s
test bench_cmp_0064_memcmp ... bench: 15 ns/iter (+/- 1) = 4333 MB/s
test bench_cmp_0064_my_memcmp ... bench: 84 ns/iter (+/- 8) = 773 MB/s
test bench_cmp_0064_rust_cmp ... bench: 15 ns/iter (+/- 1) = 4333 MB/s
test bench_cmp_0128_memcmp ... bench: 20 ns/iter (+/- 2) = 6450 MB/s
test bench_cmp_0128_my_memcmp ... bench: 149 ns/iter (+/- 24) = 865 MB/s
test bench_cmp_0128_rust_cmp ... bench: 20 ns/iter (+/- 2) = 6450 MB/s
test bench_cmp_0256_memcmp ... bench: 29 ns/iter (+/- 2) = 8862 MB/s
test bench_cmp_0256_my_memcmp ... bench: 271 ns/iter (+/- 43) = 948 MB/s
test bench_cmp_0256_rust_cmp ... bench: 30 ns/iter (+/- 11) = 8566 MB/s
test bench_cmp_1024_memcmp ... bench: 114 ns/iter (+/- 12) = 8991 MB/s
test bench_cmp_1024_my_memcmp ... bench: 1,019 ns/iter (+/- 143) = 1005 MB/s
test bench_cmp_1024_rust_cmp ... bench: 114 ns/iter (+/- 14) = 8991 MB/s
test bench_cmp_4096_memcmp ... bench: 309 ns/iter (+/- 49) = 13258 MB/s
test bench_cmp_4096_my_memcmp ... bench: 4,036 ns/iter (+/- 750) = 1015 MB/s
test bench_cmp_4096_rust_cmp ... bench: 314 ns/iter (+/- 113) = 13047 MB/s
test bench_eq_0001_my_memeq ... bench: 4 ns/iter (+/- 1) = 500 MB/s
test bench_eq_0001_rust_eq ... bench: 3 ns/iter (+/- 1) = 666 MB/s
test bench_eq_0002_my_memeq ... bench: 5 ns/iter (+/- 0) = 600 MB/s
test bench_eq_0002_rust_eq ... bench: 5 ns/iter (+/- 1) = 600 MB/s
test bench_eq_0003_my_memeq ... bench: 8 ns/iter (+/- 1) = 500 MB/s
test bench_eq_0003_rust_eq ... bench: 6 ns/iter (+/- 1) = 666 MB/s
test bench_eq_0004_my_memeq ... bench: 8 ns/iter (+/- 1) = 625 MB/s
test bench_eq_0004_rust_eq ... bench: 7 ns/iter (+/- 0) = 714 MB/s
test bench_eq_0005_my_memeq ... bench: 10 ns/iter (+/- 1) = 600 MB/s
test bench_eq_0005_rust_eq ... bench: 9 ns/iter (+/- 3) = 666 MB/s
test bench_eq_0006_my_memeq ... bench: 10 ns/iter (+/- 1) = 700 MB/s
test bench_eq_0006_rust_eq ... bench: 10 ns/iter (+/- 2) = 700 MB/s
test bench_eq_0007_my_memeq ... bench: 13 ns/iter (+/- 1) = 615 MB/s
test bench_eq_0007_rust_eq ... bench: 11 ns/iter (+/- 1) = 727 MB/s
test bench_eq_0008_my_memeq ... bench: 13 ns/iter (+/- 1) = 692 MB/s
test bench_eq_0008_rust_eq ... bench: 12 ns/iter (+/- 0) = 750 MB/s
test bench_eq_0015_my_memeq ... bench: 26 ns/iter (+/- 2) = 615 MB/s
test bench_eq_0015_rust_eq ... bench: 21 ns/iter (+/- 1) = 761 MB/s
test bench_eq_0016_my_memeq ... bench: 24 ns/iter (+/- 7) = 708 MB/s
test bench_eq_0016_rust_eq ... bench: 22 ns/iter (+/- 1) = 772 MB/s
test bench_eq_0032_my_memeq ... bench: 52 ns/iter (+/- 2) = 634 MB/s
test bench_eq_0032_rust_eq ... bench: 42 ns/iter (+/- 9) = 785 MB/s
test bench_eq_0064_my_memeq ... bench: 100 ns/iter (+/- 5) = 650 MB/s
test bench_eq_0064_rust_eq ... bench: 89 ns/iter (+/- 10) = 730 MB/s
test bench_eq_0128_my_memeq ... bench: 193 ns/iter (+/- 13) = 668 MB/s
test bench_eq_0128_rust_eq ... bench: 148 ns/iter (+/- 17) = 871 MB/s
test bench_eq_0256_my_memeq ... bench: 348 ns/iter (+/- 49) = 738 MB/s
test bench_eq_0256_rust_eq ... bench: 278 ns/iter (+/- 78) = 924 MB/s
test bench_eq_1024_my_memeq ... bench: 1,324 ns/iter (+/- 183) = 774 MB/s
test bench_eq_1024_rust_eq ... bench: 1,008 ns/iter (+/- 68) = 1016 MB/s
test bench_eq_4096_my_memeq ... bench: 5,206 ns/iter (+/- 363) = 786 MB/s
test bench_eq_4096_rust_eq ... bench: 3,947 ns/iter (+/- 1,189) = 1038 MB/s
test result: ok. 0 passed; 0 failed; 0 ignored; 80 measured
Running target/release/memcmp-8e6da4379eccaab6
running 0 tests
test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured