adwn on Google’s recruiting system is famously brutal. Many workers think it’s failing

Comment on Google’s recruiting system is famously brutal. Many workers think it’s failing parent

An optimizing compiler will turn div-by-constant and mod-by-constant into multiplications and bitshifts. For example, the Rust compiler: https://play.rust-lang.org/?version=stable&mode=release&edit... (select "Show assembly" on the top-left button).

    pub fn divmod10(x: u32) -> (u32, u32) {
       (x / 10, x % 10)
    }

generates

    mov ecx, edi
    mov eax, 3435973837
    imul rax, rcx
    shr rax, 35
    lea ecx, [rax + rax]
    lea ecx, [rcx + 4\*rcx]
    sub edi, ecx
    mov edx, edi
    ret

kongin 4y

It's still not as efficient since you're breaking on base 10 digit boundaries, not base 2, the most efficient encoding will be base 3, but alas we don't have ternary computers.

adwn 4y

But it's a much more compact than that glibc monstrosity is. Sure, the glibc version will win in a micro-benchmark, but micro-benchmarks don't capture the effect on the instruction cache.

kongin 4y

https://en.wikipedia.org/wiki/Radix_economy

Using a decimal expansion adds 25% overhead from pure maths. Your cache will be larger if you're working in base ten regardless of what optimizations your compiler does.

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