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From: Rich Felker <dalias@libc.org>
To: Stefan Kanthak <stefan.kanthak@nexgo.de>
Cc: Szabolcs Nagy <nsz@port70.net>, musl@lists.openwall.com
Subject: Re: [musl] [PATCH #2] Properly simplified nextafter()
Date: Sun, 15 Aug 2021 12:49:04 -0400	[thread overview]
Message-ID: <20210815164903.GJ13220@brightrain.aerifal.cx> (raw)
In-Reply-To: <FC3AE92153FD428B82DC324E6F64842A@H270>

On Sun, Aug 15, 2021 at 06:29:08PM +0200, Stefan Kanthak wrote:
> Rich Felker <dalias@libc.org> wrote:
> 
> > On Sun, Aug 15, 2021 at 05:19:05PM +0200, Stefan Kanthak wrote:
> >> Szabolcs Nagy <nsz@port70.net> wrote:
> >> 
> >> > * Stefan Kanthak <stefan.kanthak@nexgo.de> [2021-08-15 09:04:55 +0200]:
> >> >> Szabolcs Nagy <nsz@port70.net> wrote:
> >> >>> you should benchmark, but the second best is to look
> >> >>> at the longest dependency chain in the hot path and
> >> >>> add up the instruction latencies.
> >> >> 
> >> >> 1 billion calls to nextafter(), with random from, and to either 0 or +INF:
> >> >> run 1 against glibc,                         8.58 ns/call
> >> >> run 2 against musl original,                 3.59
> >> >> run 3 against musl patched,                  0.52
> >> >> run 4 the pure floating-point variant from   0.72
> >> >>       my initial post in this thread,
> >> >> run 5 the assembly variant I posted.         0.28 ns/call
> >> >
> >> > thanks for the numbers. it's not the best measurment
> >> 
> >> IF YOU DON'T LIKE IT, PERFORM YOUR OWN MEASUREMENT!
> > 
> > The burden of performing a meaningful measurement is on the party who
> > says there's something that needs to be changed.
> 
> I offered you two patches which speed a rather simple function by a
> measured factor of 5 and 7 respectively. IF YOU DOUBT THESE NUMBERS,
> PROVIDE YOUR OWN!

I really have better things to be doing than putting up with repeated
toxic interactions for the sake of a supposed miniscule improvement in
something nobody has identified as having any problem to begin with.

If you want to engage constructively, you're welcome to. This is not
it.

Rich

  reply	other threads:[~2021-08-15 16:49 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-10  6:23 [musl] [PATCH] " Stefan Kanthak
2021-08-10 21:34 ` Szabolcs Nagy
2021-08-10 22:53   ` Stefan Kanthak
2021-08-11  2:40     ` Rich Felker
2021-08-11 15:44       ` Stefan Kanthak
2021-08-11 16:09         ` Rich Felker
2021-08-11 16:50           ` Stefan Kanthak
2021-08-11 17:57             ` Rich Felker
2021-08-11 22:16               ` Szabolcs Nagy
2021-08-11 22:43                 ` Stefan Kanthak
2021-08-12  0:59                   ` Rich Felker
2021-08-11  8:23     ` Szabolcs Nagy
2021-08-13 12:04   ` [musl] [PATCH #2] " Stefan Kanthak
2021-08-13 15:59     ` Rich Felker
2021-08-13 18:30       ` Stefan Kanthak
2021-08-14  4:07         ` Damian McGuckin
2021-08-14 22:45           ` Szabolcs Nagy
2021-08-14 23:46     ` Szabolcs Nagy
2021-08-15  7:04       ` Stefan Kanthak
2021-08-15  7:46         ` Ariadne Conill
2021-08-15 13:59           ` Rich Felker
2021-08-15 14:57             ` Ariadne Conill
2021-08-15  8:24         ` Damian McGuckin
2021-08-15 14:03           ` Rich Felker
2021-08-15 15:10             ` Damian McGuckin
2021-08-15 14:56         ` Szabolcs Nagy
2021-08-15 15:19           ` Stefan Kanthak
2021-08-15 15:48             ` Rich Felker
2021-08-15 16:29               ` Stefan Kanthak
2021-08-15 16:49                 ` Rich Felker [this message]
2021-08-15 20:52                   ` Stefan Kanthak
2021-08-15 21:48                     ` Rich Felker
2021-08-15 15:52             ` Ariadne Conill
2021-08-15 16:09               ` Rich Felker

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