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| From | David Brown <david.brown@hesbynett.no> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: "Lete2??s Stop Bashing C" |
| Date | 2016-12-09 10:39 +0100 |
| Organization | A noiseless patient Spider |
| Message-ID | <o2du22$e8b$1@dont-email.me> (permalink) |
| References | (15 earlier) <o2a5ha$mb5$1@dont-email.me> <o2b8ql$bhk$1@dont-email.me> <490a9713-ac98-47f5-a8ec-a0c7825ee97c@googlegroups.com> <o2chri$stf$1@dont-email.me> <o2cid3$uu7$1@dont-email.me> |
On 08/12/16 22:14, jacobnavia wrote: > Le 08/12/2016 à 22:05, David Brown a écrit : >> On the other hand, with a nice simple 64-bit sum stored in r4, r7 then >> the critical lines become: >> >> ADDS r4, r0, r4 // r4 = r0 + r4, set carry flag >> ADC r7, r7, #0 // r7 = r7 + 0 + carry flag > > And why you avoid using the V bit of the APSR? > > Why not use the actual hardware? It is always faster than "doing it by > hand". Did you read the rest of what I wrote? You are so keen on fighting and arguing that you fail to see when people write something that /supports/ what you are saying. If you want to use the overflow bit, you have to check it after /every/ addition, and that is three instructions per addition instead of two. I also suggested that when you have hardware that /really/ helps, such as saturated arithmetic support on Cortex M4 devices, then you can use a single instruction here and test the saturated flag at the end. Key to this is that the "saturated" flag is sticky - instructions set it, but don't clear it. The "overflow" flag is volatile - instructions set and clear it, so you must test as you go along. So yes, support for low-level features of hardware can be a good thing. But no, it should not be standardised in C - this kind of thing is highly target dependent. And no, "overflow" is not special enough to be treated as vital to C, even though it is more common than (for example) ARM's saturate flag.
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"Let’s Stop Bashing C" Lynn McGuire <lynnmcguire5@gmail.com> - 2016-12-05 19:57 -0600
Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 02:34 +0000
Re: "Let’s Stop Bashing C" BGB <cr88192@hotmail.com> - 2016-12-06 00:13 -0600
Re: "Let’s Stop Bashing C" BartC <bc@freeuk.com> - 2016-12-06 23:15 +0000
Re: "Let’s Stop Bashing C" BGB <cr88192@hotmail.com> - 2016-12-06 21:16 -0600
Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 11:54 +0000
Re: "Let’s Stop Bashing C" BartC <bc@freeuk.com> - 2016-12-06 12:07 +0000
Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 12:25 +0000
Re: "Let’s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-06 14:07 +0100
Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 13:40 +0000
Re: "Let’s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 19:40 +0100
Re: "Lete2��s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-06 13:55 -0500
Re: "Lete2��s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 19:13 +0000
Re: "Lete2��s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-06 11:51 -0800
Re: "Lete2��s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 12:22 -0800
Re: "Lete2��s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 20:16 +0100
Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 11:20 -0800
Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-06 22:15 +0100
Re: "Lete2�™s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-06 16:49 -0500
Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 14:24 -0800
Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:07 +0100
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-07 22:04 +0100
Re: micro-architectural details jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 23:44 +0100
Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-07 23:02 +0000
Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-07 15:28 -0800
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 21:36 +0100
Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 12:56 -0800
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:03 +0100
Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 14:21 -0800
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:36 +0100
Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-08 21:59 +0000
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:25 +0100
Re: micro-architectural details supercat@casperkitty.com - 2016-12-08 14:34 -0800
Re: micro-architectural details Noob <root@127.0.0.1> - 2016-12-08 23:59 +0100
Re: micro-architectural details Melzzzzz <mel@zzzzz.com> - 2016-12-09 00:18 +0100
Re: micro-architectural details fir <profesor.fir@gmail.com> - 2016-12-09 00:06 -0800
Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-09 11:35 +0000
Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-09 12:12 +0000
Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-09 13:33 +0100
Re: micro-architectural details Malcolm McLean <malcolm.mclean5@btinternet.com> - 2016-12-09 15:41 -0800
Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-10 09:28 -0800
Re: micro-architectural details supercat@casperkitty.com - 2016-12-10 09:58 -0800
Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 22:53 -0800
Re: micro-architectural details Robert Wessel <robertwessel2@yahoo.com> - 2016-12-11 03:10 -0600
Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-11 13:48 +0000
Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-11 14:43 +0000
Re: micro-architectural details Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 16:23 +0000
Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-11 12:53 -0800
Re: micro-architectural details Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-11 21:27 +0000
Re: micro-architectural details supercat@casperkitty.com - 2016-12-11 08:46 -0800
Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:14 -0800
Re: micro-architectural details supercat@casperkitty.com - 2016-12-15 08:25 -0800
Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-14 21:11 -0800
Re: micro-architectural details BartC <bc@freeuk.com> - 2016-12-15 14:28 +0000
Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-11 18:38 +0100
Re: micro-architectural details Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-15 00:25 -0800
Re: micro-architectural details supercat@casperkitty.com - 2016-12-09 07:42 -0800
Re: micro-architectural details Keith Thompson <kst-u@mib.org> - 2016-12-09 11:54 -0800
Re: micro-architectural details David Brown <david.brown@hesbynett.no> - 2016-12-09 10:27 +0100
Re: other missing features (no-brainers) Noob <root@127.0.0.1> - 2016-12-09 17:05 +0100
Re: micro-architectural details jt@toerring.de (Jens Thoms Toerring) - 2016-12-09 09:51 +0000
Re: "Lete2�™s Stop Bashing C" Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-06 20:42 -0500
Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 14:16 -0800
Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:31 +0100
Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-06 15:55 -0800
Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 01:01 +0100
Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-06 16:42 -0800
Re: "Lete2�™s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 01:55 +0100
Re: "Lete2�™s Stop Bashing C" supercat@casperkitty.com - 2016-12-07 07:11 -0800
Re: "Lete2??s Stop Bashing C" Ike Naar <ike@iceland.freeshell.org> - 2016-12-06 23:05 +0000
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 00:43 +0100
Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-07 03:06 +0000
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:47 +0100
Re: "Lete2??s Stop Bashing C" Thiago Adams <thiago.adams@gmail.com> - 2016-12-07 03:10 -0800
Re: "Lete2??s Stop Bashing C" Thiago Adams <thiago.adams@gmail.com> - 2016-12-07 03:13 -0800
Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-07 11:47 +0000
Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-07 12:08 +0000
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-07 23:45 +0100
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 00:22 +0100
Re: "Lete2??s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 15:32 -0800
Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 01:25 +0100
Re: "Let's Stop Bashing C" supercat@casperkitty.com - 2016-12-07 16:36 -0800
Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 17:09 -0800
Re: "Let's Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 10:28 +0100
Re: "Let's Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-08 08:34 -0800
Re: "Let's Stop Bashing C" Gareth Owen <gwowen@gmail.com> - 2016-12-08 20:08 +0000
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 10:24 +0100
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 15:49 +0100
Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 15:23 +0000
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 16:58 +0100
Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 18:57 +0000
Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 15:29 +0000
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 17:09 +0100
Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 16:41 +0000
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 17:04 +0100
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 17:15 +0100
Re: "Lete2??s Stop Bashing C" Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-08 11:34 -0500
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 18:40 +0100
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 10:00 -0800
Re: "Lete2??s Stop Bashing C" Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-08 19:05 +0000
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 19:58 +0100
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 08:22 -0800
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 20:12 +0100
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 11:40 -0800
Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-10 02:44 -0600
Re: "Lete2??s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-08 16:22 +0000
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 20:14 +0100
Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-10 02:19 -0600
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 07:44 -0800
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-08 22:05 +0100
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-08 22:14 +0100
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-09 10:39 +0100
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-08 13:33 -0800
Re: "Lete2??s Stop Bashing C" David Brown <david.brown@hesbynett.no> - 2016-12-09 11:13 +0100
Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-07 06:27 -0600
Re: "Lete2??s Stop Bashing C" supercat@casperkitty.com - 2016-12-07 07:17 -0800
Re: "Lete2??s Stop Bashing C" Robert Wessel <robertwessel2@yahoo.com> - 2016-12-07 23:43 -0600
Re: "Lete2??s Stop Bashing C" Ike Naar <ike@iceland.freeshell.org> - 2016-12-07 07:41 +0000
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:45 +0100
Re: "Lete2??s Stop Bashing C" Keith Thompson <kst-u@mib.org> - 2016-12-07 09:22 -0800
Re: "Lete2??s Stop Bashing C" jacobnavia <jacob@jacob.remcomp.fr> - 2016-12-07 11:49 +0100
Re: "Lete2??s Stop Bashing C" Jerry Stuckle <jstucklex@attglobal.net> - 2016-12-07 09:28 -0500
Re: "Lete2��s Stop Bashing C" "James R. Kuyper" <jameskuyper@verizon.net> - 2016-12-06 14:22 -0500
Re: Subject field encoding Noob <root@127.0.0.1> - 2016-12-07 21:40 +0100
Re: Subject field encoding Keith Thompson <kst-u@mib.org> - 2016-12-07 13:01 -0800
Re: Subject field encoding Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2016-12-07 16:02 -0500
Re: "Lete2�™s Stop Bashing C" asetofsymbols@gmail.com - 2016-12-08 15:50 -0800
Re: "Let’s Stop Bashing C" Richard Heathfield <rjh@cpax.org.uk> - 2016-12-06 19:07 +0000
Re: "Let€™s Stop Bashing C" Xcott Craver <nospam@nospam.invalid> - 2016-12-07 16:48 -0500
Re: "Let's Stop Bashing C" Noob <root@127.0.0.1> - 2016-12-07 23:29 +0100
Re: "Let’s Stop Bashing C" "Mr. Man-wai Chang" <toylet.toylet@gmail.com> - 2016-12-06 12:06 +0800
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