// Compile with -C opt-level=3 -C target-cpu=native to see autovectorization | |
// assumes input's length is a multiple of 64 | |
pub fn sum_array(input: &[i32]) -> i32 { | |
let len = input.len(); | |
let input = input.as_ptr(); | |
if len & 63 != 0 { | |
unsafe { std::hint::unreachable_unchecked() } | |
} | |
let mut sum = 0; | |
for i in 0..len { | |
sum += unsafe { *input.add(i) }; | |
} | |
sum | |
} |