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| From | Philipp Klaus Krause <pkk@spth.de> |
|---|---|
| Newsgroups | comp.std.c |
| Subject | Re: bit-fields of type unsigned long and unsigned long long |
| Date | 2021-06-23 13:22 +0200 |
| Message-ID | <sav5i2$ccq$1@solani.org> (permalink) |
| References | <sastag$a33$1@solani.org> |
Am 22.06.21 um 16:49 schrieb Philipp Klaus Krause: > Since bit-fields of type unsigned long and unsigned long long are > useful, commonly suppoted by implementations, and commonly used, I'd > like to see the standard support them. > > Here's a draft of a proposal for that: > > http://www.colecovision.eu/stuff/proposal-unsigned-long-bit-field.html > I now realize that in some way, the type question is even harder for types wider than int than for types narrower than it. We already have divergence on the type between GCC and clang for unsigned int bit-fields. But there it only matters when you use _Generic (i.e. for clang _Generic on an unsigned int bit-field will match unsigned int, but for clang it won't). For other uses, we have the integer promotions that work on anything smaller than int. So x.b << z behaves similar on GCC vs clang, since x.b is promoted to int (there is still the difference of promoting to int vs. promoting to unsigned int). But for an unsigned long bit-field x.b << z will often give a different result on GCC vs clang: The topmost bits of the result might be 1 for clang where they are 0 for GCC (as clang does the shift on an unsigned long, while GCC does it on a type just as wide as the bit-field).
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bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-22 16:49 +0200
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-22 17:18 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-22 11:17 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 08:25 +0200
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-23 08:59 +0200
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 13:12 +0200
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-23 14:14 +0200
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 17:45 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 10:22 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 19:52 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 16:12 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 10:41 +0200
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 10:32 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-23 00:39 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 13:22 +0200
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 18:27 +0200
Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-06-23 10:53 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-23 20:13 +0200
Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-06-24 11:48 -0700
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 12:23 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 22:40 +0200
Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 09:13 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-24 22:14 +0200
Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 09:23 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 11:02 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 11:06 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-24 23:11 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-24 15:16 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 10:43 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 02:02 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 13:54 +0200
Re: bit-fields of type unsigned long and unsigned long long Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-25 13:07 +0100
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 15:17 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 08:22 -0700
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 18:22 +0200
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 13:28 -0700
Re: bit-fields of type unsigned long and unsigned long long Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-06-25 19:12 +0100
Re: bit-fields of type unsigned long and unsigned long long Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-07-10 08:58 -0700
Re: bit-fields of type unsigned long and unsigned long long Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-06-25 08:09 -0700
Re: bit-fields of type unsigned long and unsigned long long Philipp Klaus Krause <pkk@spth.de> - 2021-06-25 14:43 +0200
Re: bit-fields of type unsigned long and unsigned long long David Brown <david.brown@hesbynett.no> - 2021-06-25 15:33 +0200
Re: bit-fields of type unsigned long and unsigned long long Jakob Bohm <jb-usenet@wisemo.com.invalid> - 2021-07-06 23:18 +0200
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