simdutf VS tpr

The project was mostly inspired by simdutf [0] which has been around for a couple of years already, and I don't think iconv has any of its vectorized implementations for other architectures.

[0] https://github.com/simdutf/simdutf

I'm actually doing something quite similar in my, in progress, unicode conversion routines.

For utf8 validation there is a clever algorithm that uses three 4-bit look-ups to detect utf8 errors: https://github.com/simdutf/simdutf/blob/master/src/icelake/i...

Aside on LMUL, if you haven't encountered it yet: rvv allows you to group vector registers when configuring the vector configuration with vsetvl such that vector instruction operate on multiple vector registers at once. That is, with LMUL=1 you have v0,v1...v31. With LMUL=2 you effectively have v0,v2,...v30, where each vector register is twice as large. with LMUL=4 v0,v4,...v28, with LMUL=8 v0,v8,...v24.

In my code, I happen to read the data with LMUL=2. The trivial implementation would just call vrgather.vv with LMUL=2, but since we only need a lookup table with 128 bits, LMUL=1 would be enough to store the lookup table (V requires a minimum VLEN of 128 bits).

So instead I do six LMUL=1 vrgather.vv's instead of three LMUL=2 vrgather.vv's because there is no lane crossing required and this will run faster in hardware: (see [0] for a relevant mico benchmark)

        # codegen for equivalent of that function

utf8 normalization, stemming, case insensitive comparison. https://github.com/unicode-rs example for rust What are options for C++? 1. translate to utf16 ( https://github.com/simdutf/simdutf ) and use icu -- slow 2. boost text, https://github.com/tzlaine/text , also slow (because the author doesn't care or couldn't care), we made a lot of patches to make our library faster than lucene, but still this part is slower than icu for utf16 (icu for utf16 also very slow...)

You can find the corresponding assembly code in this repository. The main branch only contains implementations based on C++ with intrinsics.

The next big thing is making it LSP-compatible. All language servers must implement UTF-16 based character offsets, which is kinda unfortunate considering that files are much more likely to be stored in UTF-8 (I think?). I don't want to do the UTF-8 -> UTF-16 transcoding, so instead I'll use the excellent simdutf library to count how much code points a UTF-8 string would take if it was transcoded into UTF-16 — which is much faster than actual transcoding. So this is what I'm going to do this week — rewriting parsers to produce UTF-16 offsets + some final benchmarking. After that is done, I'll consider the "research" part of this project completed and will start writing an actual Markdown parser.

You can find the assembly code here: https://github.com/simdutf/simdutf/tree/clausecker The corresponding C++ code is in the main branch.

Or via an ultrafast simdutf.

Hey, this might interest you, as a similar thing could be implemented as bridge between freenet and the clearnet. I've been working on this for a while now. https://github.com/Alonely0/tpr

I'm throwing away all the code I had written and implementing my TPR protocol from scratch, I'll be using tower this time, lesson learned...

I'm more of a pomegranate guy

I'm implementing tpr, so I'll definitely take a look at this

Lariv is a thread-safe, self-memory-managed vector with no guaranteed sequential insert. It internally uses a linked ring buffer, that unlike traditional ring buffers, is growable, and very importantly, it doesn't reallocate the whole buffer as part of the process. It has been born inside the TPR project, and it is designed for storing client connections on TPR servers, which usually are short-lived data that have to be accessed via 128-bits integers. This is basically the dashmap for vectors.

In my case I use IDs for pairing multiplexed connections to encryption keys. I'm implementing The Pomegranate Router.