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Groups > comp.lang.c > #125469
| Subject | Re: What happened to short float? |
|---|---|
| Newsgroups | comp.lang.c |
| References | <p3nt6t$uid$1@solani.org> <p3o61s$66s$1@dont-email.me> <p3q3am$cd4$1@solani.org> |
| From | bartc <bc@freeuk.com> |
| Message-ID | <8B08C.431211$eO2.190050@fx34.am4> (permalink) |
| Organization | virginmedia.com |
| Date | 2018-01-18 12:40 +0000 |
On 18/01/2018 12:18, Philipp Klaus Krause wrote: > Am 17.01.2018 um 19:52 schrieb jacobnavia: >> Le 17/01/2018 à 17:21, Philipp Klaus Krause a écrit : >>> At the 2016 London meeting of WG14, adding a new short float type >>> (N2016) was discussed, and there was a clear consensus to move forward. >>> >>> What has happened about short float since? >>> >>> Philipp >>> >> lcc hasn't implemented them because of time constraints. >> >> They are a memory only format. The x86 transforms them on floats on >> reading them from RAM. The same for ARM. >> >> They reduce the size of the data at the expense of precision. For many >> applications that can be a bonus, it depends. >> > > I'm somewhat interested in them, since their implementation could be > cosiderably faster than float/double on machines without hardware > support for floating-point operations. Typical examples would be most > 8-bit µCs. If the 8-bit machine has some 16-bit support, then 24-bit is another option, which gives more precision and range (somewhat better than the 4-figure log tables I used at school actually). That would be 8-bit sign/exponent and 16-bit mantissa, which can be accessed more tidily. There can't be an extra implied bit unless it can be done without requiring 17-bit arithmetic. I understand the official 16-bit format uses a 10-bit mantissa (11 in total) so some 16-bit calculations are needed anyway. -- bartc
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What happened to short float? Philipp Klaus Krause <pkk@spth.de> - 2018-01-17 17:21 +0100
Re: What happened to short float? "James R. Kuyper" <jameskuyper@verizon.net> - 2018-01-17 11:42 -0500
Re: What happened to short float? Chad <cdalten@gmail.com> - 2018-01-17 09:12 -0800
Re: What happened to short float? scott@slp53.sl.home (Scott Lurndal) - 2018-01-17 17:31 +0000
Re: What happened to short float? jacobnavia <jacob@jacob.remcomp.fr> - 2018-01-17 19:52 +0100
Re: What happened to short float? Philipp Klaus Krause <pkk@spth.de> - 2018-01-18 13:18 +0100
Re: What happened to short float? bartc <bc@freeuk.com> - 2018-01-18 12:40 +0000
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