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Zlib-rs is faster than C

(trifectatech.org)
341 points dochtman | 1 comments | | HN request time: 0s | source
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YZF ◴[] No.43381858[source]
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?

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Aurornis ◴[] No.43381931[source]
Using unsafe blocks in Rust is confusing when you first see it. The idea is that you have to opt-out of compiler safety guarantees for specific sections of code, but they’re clearly marked by the unsafe block.

In good practice it’s used judiciously in a codebase where it makes sense. Those sections receive extra attention and analysis by the developers.

Of course you can find sloppy codebases where people reach for unsafe as a way to get around Rust instead of writing code the Rust way, but that’s not the intent.

You can also find die-hard Rust users who think unsafe should never be used and make a point to avoid libraries that use it, but that’s excessive.

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timschmidt ◴[] No.43381986[source]
Unsafe is a very distinct code smell. Like the hydrogen sulfide added to natural gas to allow folks to smell a gas leak.

If you smell it when you're not working on the gas lines, that's a signal.

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throwaway150 ◴[] No.43384810[source]
> Like the hydrogen sulfide added to natural gas to allow folks to smell a gas leak.

I am 100% sure that the smell they add to natural gas does not smell like rotten eggs.

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beacon294 ◴[] No.43385005[source]
They add mercaptan which is like 1000x the rotten egg smell of H2S.
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1. taejo ◴[] No.43387099{3}[source]
Mercaptan is a group of compounds, more than one of which are used as gas odorants, so in some places, gas smells of rotten eggs, similar to H2S, while in others gas doesn't smell like that at all, but a quite distinct smell that's reminiscent garlic and durian.