Zlib-rs is faster than C

I found out I already know Rust:

        unsafe {
            let x_tmp0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x10);
            xmm_crc0 = _mm_clmulepi64_si128(xmm_crc0, crc_fold, 0x01);
            xmm_crc1 = _mm_xor_si128(xmm_crc1, x_tmp0);
            xmm_crc1 = _mm_xor_si128(xmm_crc1, xmm_crc0);

Kidding aside, I thought the purpose of Rust was for safety but the keyword unsafe is sprinkled liberally throughout this library. At what point does it really stop mattering if this is C or Rust?

Presumably with inline assembly both languages can emit what is effectively the same machine code. Is the Rust compiler a better optimizing compiler than C compilers?

Not to mention they link to libc.. All rust code does last I checked…

There is an option to not link to it for instances like OS writing and embedded. Writing everything in pure Rust without libc is entirely possible, even if an effort in losing sanity when you're reimplementing every syscall you need from scratch.

But even then, your code is calling out to kernel functions which are probably written in C or assembly, and therefore "dangerous."

Rust code safety is overhyped frequently, but reducing an attack surface is still an improvement over not doing so.

Ironically using C without libc turns out to be easier (except for portability of course). The kernel ABI is much more sane than <stdio.h>. The only useful parts of libc are DNS resolution and text formatting, both of which it does rather poorly.