Groups > comp.lang.c++ > #121926

Re: a MSVC and glibc-compatible fmod()

From	Michael S <already5chosen@yahoo.com>
Newsgroups	comp.lang.c++
Subject	Re: a MSVC and glibc-compatible fmod()
Date	2025-03-10 13:17 +0200
Organization	A noiseless patient Spider
Message-ID	<20250310131727.00001445@yahoo.com> (permalink)
References	(10 earlier) <vqjq3v$m7h6$1@raubtier-asyl.eternal-september.org> <20250309140932.0000303d@yahoo.com> <vqkf9p$qh6l$1@raubtier-asyl.eternal-september.org> <20250309200407.0000036c@yahoo.com> <vqm0id$17aku$1@raubtier-asyl.eternal-september.org>

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On Mon, 10 Mar 2025 07:24:18 +0100
Bonita Montero <Bonita.Montero@gmail.com> wrote:

> Am 09.03.2025 um 19:04 schrieb Michael S:
> 
> > I already said that I don't approve non-portable constructs like
> > _mm_getcsr()/_mm_setcsr() except when they help important cases and
> > help ALOT. Neither applies here.  
> 
> I dropped getting and setting the MSCSR-register to set the roun-
> ding mode. Now I set the rounding mode directly with the intrinsics
> _mm_div_round_sd and and _mm_fmadd_round_sd. Now this more manual
> code does help "ALOT", i.e. the solution is 2/3 faster than your
> initial solution with clang++-18 under Linux.

I can't check your claim about speed, because the code does not compile.
Compiler has no idea WTF is xtrunc. But considering that so far all
your claims about speed were false, I can safely assume that this one
is false as well.

> But there's still a problem with the denormals.
> 

On y or on x?
Subnormal values of x can be nicely handled by quick path with 0
additional characters of code.

BTW, for last 20-25 years IEEE-754 prefers to call binary floating
point numbers in range (0:DBL_MIN) 'subnormal' rather than 'denormal'.
I'd guess that it is because the term 'denormal' has wider meaning.

Thread

a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 11:48 +0100
  Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 12:00 +0000
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 13:48 +0100
      Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 13:09 +0000
        Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 14:22 +0100
          Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:13 +0200
            Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-24 16:19 +0100
              Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:52 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 09:09 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:17 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-25 17:26 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:45 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 16:57 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-25 19:17 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 18:58 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 00:36 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-26 04:15 +0100
                Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-26 08:16 +0000
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 14:27 +0200
                Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-26 14:39 +0000
                FP_CONTRACT was : a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-28 16:28 +0200
                Re: FP_CONTRACT was : a MSVC and glibc-compatible fmod() Tim Rentsch <tr.17687@z991.linuxsc.com> - 2025-03-01 08:35 -0800
        Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 16:22 +0200
          Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 15:10 +0000
            Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-24 17:33 +0200
              Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-24 16:48 +0000
  Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-24 22:21 +0000
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-25 07:37 +0100
      Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-25 23:03 +0000
        Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-26 02:00 +0200
        Re: a MSVC and glibc-compatible fmod() Wuns Haerst <Wuns.Haerst@wurstfabrik.at> - 2025-02-26 04:01 +0100
    Re: a MSVC and glibc-compatible fmod() Muttley@DastardlyHQ.org - 2025-02-25 08:24 +0000
  Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-27 21:16 +0000
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 07:59 +0100
    Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-02-28 12:35 +0200
      Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 18:12 +0000
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 19:23 +0100
  Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 18:30 +0000
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 19:31 +0100
      Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-02-28 19:47 +0000
        Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-02-28 20:49 +0100
          Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 14:37 +0000
            Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 16:58 +0100
              Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 17:11 +0000
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 21:02 +0100
                Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 20:32 +0000
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-01 21:37 +0100
                Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-01 20:45 +0000
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 09:40 +0100
  Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-01 22:55 +0200
    Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 18:54 +0200
      Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:59 +0100
  Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 15:41 +0200
    Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:10 +0100
      Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-02 16:22 +0000
        Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 17:26 +0100
          Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:07 +0200
            Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:09 +0100
              Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:11 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:52 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:55 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 20:09 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:14 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:57 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 22:58 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 12:52 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 18:10 +0200
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 23:55 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-07 09:51 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 18:20 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 17:30 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 19:27 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-03 18:39 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-03 02:01 +0200
        Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 19:37 +0200
          Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 18:41 +0100
            Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-02 20:00 +0200
              Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-02 19:01 +0100
      Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 01:31 +0200
        Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 07:41 +0100
          Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 11:08 +0200
            Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 10:31 +0100
              Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 11:46 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 10:54 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 12:09 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 11:21 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:09 +0200
                Re: a MSVC and glibc-compatible fmod() Mr Flibble <leigh@i42.co.uk> - 2025-03-09 15:26 +0000
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 17:02 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 19:55 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:10 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:27 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 17:23 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 20:04 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 19:11 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 20:11 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 07:24 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 10:46 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 14:26 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 13:45 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 16:33 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 15:46 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 16:59 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 16:11 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 17:43 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 17:13 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 19:51 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 19:00 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 20:38 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 22:34 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 22:36 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 12:47 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 23:52 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 23:57 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 09:34 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 12:29 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 12:12 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 13:34 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 13:10 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 14:55 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-11 14:08 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 15:46 +0200
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 13:51 +0200
                Re: a MSVC and glibc-compatible fmod() James Kuyper <jameskuyper@alumni.caltech.edu> - 2025-03-11 14:21 -0400
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-11 20:28 +0200
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-16 13:48 +0200
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-10 13:17 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 12:53 +0100
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-10 12:54 +0100
              Re: a MSVC and glibc-compatible fmod() wij <wyniijj5@gmail.com> - 2025-03-09 18:51 +0800
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 12:56 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:23 +0200
                Re: a MSVC and glibc-compatible fmod() Bonita Montero <Bonita.Montero@gmail.com> - 2025-03-09 13:39 +0100
                Re: a MSVC and glibc-compatible fmod() Michael S <already5chosen@yahoo.com> - 2025-03-09 14:56 +0200

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