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Zlib-rs is faster than C

(trifectatech.org)
341 points dochtman | 1 comments | | HN request time: 0.206s | 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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gigatexal ◴[] No.43386705[source]
Someone mentioned to me that for something as simple as a Linked list you have to use unsafe in rust

Update its how the std lib does it: https://doc.rust-lang.org/src/alloc/collections/linked_list....

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1. miki123211 ◴[] No.43391048[source]
This is far less of a problem than it would be in a C-like language, though.

You can implement that linked list just once, audit the unsafe parts extensively, provide a fully safe API to clients, and then just use that safe API in many different places. You don't need thousands of project-specific linked list reimplementations.