Re: [text] SIMD UTF-8 decoding

From: degski (degski_at_[hidden])
Date: 2020-06-17 01:11:29

On Mon, 15 Jun 2020 at 14:06, Phil Endecott via Boost <boost_at_[hidden]>
wrote:

> Dear All,
>
> I have been looking at the UTF-8 decoding code in the proposed
> Boost.Text, as this is a problem I've looked at myself in the past.
> I've mentioned an issue with the copyright in another message.
> Here are my other observations.
>
> 1. The SIMD code is x86-specific.  It doesn't need to be; I think
> it could use gcc's vector builtins to do the same thing and be
> portable to other SIMD implementations.  (Clang provides the same
> builtins; I'm not sure about what you need to do on MSVC/Windows.)
> See: https://gcc.gnu.org/onlinedocs/gcc/Vector-Extensions.html

Bar writing intel assembler for ml64 [a stand-alone assembler, the only
option on Windows-x64 is Intel Intrinsics (
https://software.intel.com/sites/landingpage/IntrinsicsGuide/# ). Over and
above the Intel Intrinsics, Microsoft offers 'a number of extensions',
which often correspond to some builtin_ in clang/gcc. I'm not sure this is
related, but there is also the vectorcall-ABI.

degski