From: Keith Packard <keithp@keithp.com>
To: Corinna Vinschen <vinschen@redhat.com>,
Pavel M <pavel.morozkin@gmail.com>
Cc: newlib@sourceware.org
Subject: Re: gcc 11.1.0: printf("%.43f\n", 0x1.52f8a8e32e982p-140): printed value is incorrectly rounded
Date: Thu, 04 Nov 2021 09:48:39 -0700 [thread overview]
Message-ID: <87ilx7vpco.fsf@keithp.com> (raw)
In-Reply-To: <YYPRCr2ZTWWuYmqc@calimero.vinschen.de>
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Corinna Vinschen <vinschen@redhat.com> writes:
> Is anybody here willing to take a look and change Newlib to gdtoa?
It might be useful for newlib to adopt the Ryū floating point conversion
code developed by Ulf Adams (currently at Google). This does correct
double conversion in 128 bits, avoiding need for arbitrary precision
math and any allocations.
https://dl.acm.org/doi/10.1145/3360595
There is a BSD licensed implementation of the core algorithm available
on github; adopting that into complete printf/scanf implementations
isn't a huge amount of work. picolibc uses this implementation.
A friend of mine posited that this could be done, and got started on it
in grad school about 20 years ago. It was very nice to see someone
actually take the time to make it happen.
--
-keith
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next prev parent reply other threads:[~2021-11-04 16:48 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CAL9Mx1uMOz2wfqbMpD_xfA=D9JkpFzVz6AR_DKHK34AvrGOP6w@mail.gmail.com>
2021-11-03 21:26 ` Fwd: " Pavel M
2021-11-04 12:24 ` Corinna Vinschen
2021-11-04 16:48 ` Keith Packard [this message]
2021-11-04 17:27 ` Dave Nadler
2021-11-04 17:58 ` Keith Packard
2021-11-04 21:28 ` Brian Inglis
2021-11-05 2:54 ` Keith Packard
2021-11-05 16:00 ` Steven Abner
2021-11-06 12:06 ` Steven Abner
2021-11-06 23:25 ` Steven Abner
2021-11-08 9:57 ` Corinna Vinschen
2021-11-04 20:57 ` Corinna Vinschen
2021-11-28 7:43 ` Takashi Yano
2021-11-28 12:38 ` Takashi Yano
2021-11-28 13:16 ` Takashi Yano
2021-11-29 10:56 ` Takashi Yano
2021-11-29 14:24 ` Takashi Yano
2021-11-29 15:55 ` Corinna Vinschen
2021-11-30 10:51 ` Takashi Yano
2021-11-30 15:09 ` Corinna Vinschen
2021-11-30 20:38 ` Takashi Yano
2021-11-30 21:17 ` Takashi Yano
2021-12-06 9:53 ` Corinna Vinschen
2021-12-06 10:26 ` Takashi Yano
2021-12-01 12:05 ` Takashi Yano
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