Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:122245
MIME-Version: 1.0
References: <CAK7R4ayXCC9_EWveFAt-BS8cJV-h9JxoLP5c+j9Y3LzPWS9xnQ@mail.gmail.com>
 <CAO__Xv6SkuD3DyNV5VM-DJKPHZboX=Pg+=5F=3aGS1tZaZAeaQ@mail.gmail.com>
 <CAJmy8YHyq6D8aB+eP8dL4jL4_Up_VO6NZTVoeNMLNkS404p3Xw@mail.gmail.com>
 <CAJmy8YHUA2yQVs3VeBpVes_rbjmsrnsAvnqxOBMY1pET91uLxw@mail.gmail.com> <CAO__Xv4GEnTFZkyHMH2giVRto_ebsMfdpyp4wQ6JnynvZSV52A@mail.gmail.com>
In-Reply-To: <CAO__Xv4GEnTFZkyHMH2giVRto_ebsMfdpyp4wQ6JnynvZSV52A@mail.gmail.com>
Date: Wed, 24 Jan 2024 17:27:12 +0100
Message-ID: <CAK7R4awBXVa+sKsBh1xddLhO9h0HUfN1+FcPLJmmVE2av9Ue4Q@mail.gmail.com>
To: internals@lists.php.net
Content-Type: multipart/alternative; boundary="000000000000a78177060fb389e8"
Subject: Re: [PHP-DEV] BLAKE3 hash
From: hans@loltek.net (Hans Henrik Bergan)

--000000000000a78177060fb389e8
Content-Type: text/plain; charset="UTF-8"

Maybe vote on it? (that was suggested in the PR too,
https://github.com/php/php-src/pull/13194#issuecomment-1900430400 )

Can think of 6 things

1: Should BLAKE3 be added to PHP? yes/no
2: Should ARM Neon (2007) optimized implementation be bundled? yes/no
3: Should x86_64 SSE2 (2000) optimized implementation be bundled? yes/no
4: Should x86_64 SSE4.1 (2007) optimized implementation be bundled? yes/no
5: Should x86_64 AVX2 (2011) optimized implementation be bundled? yes/no
6: Should x86_64 AVX512 (2016) optimized implementation be bundled? yes/no

(wrote the year processors were actually released, not the year
instructions were proposed/announced)

Arguments against SSE2 and SSE4.1: pretty much all modern CPUs supporting
SSE2/SSE4.1 also support AVX2.

Argument against AVX512: CloudFlare said in a blogpost that when a core
starts executing AVX512 instructions, it decreases the clock speed of
neighboring cores so much that, quote:
>OpenSSL serves 10% fewer requests per second. And that is a huge number!
It is equivalent to giving up on two cores, for nothing

and another quote:

>If you do not require AVX-512 for some specific high performance tasks, I
suggest you disable AVX-512 execution on your server or desktop, to avoid
accidental AVX-512 throttling.

(ref https://blog.cloudflare.com/on-the-dangers-of-intels-frequency-scaling
)
that AVX512 issue is probably cpu-specific and will probably be mitigated
in newer CPU releases
(idk if AMD is even affected, or if it is purely a Intel issue)

thus they may be worthy of a vote

--000000000000a78177060fb389e8--