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Groups > comp.lang.c++ > #68809
| From | Soviet_Mario <SovietMario@CCCP.MIR> |
|---|---|
| Newsgroups | comp.lang.c++, comp.lang.c |
| Subject | Re: alloca()-support |
| Date | 2019-09-30 20:01 +0200 |
| Organization | A noiseless patient Spider |
| Message-ID | <qmtft6$khj$1@dont-email.me> (permalink) |
| References | <qmsqs0$472$1@news.albasani.net> <qmtbkq$pmp$1@dont-email.me> <1bd0fhvgys.fsf@pfeifferfamily.net> |
Cross-posted to 2 groups.
On 30/09/2019 19:20, Joe Pfeiffer wrote:
> Soviet_Mario <SovietMario@CCCP.MIR> writes:
>
>> On 30/09/2019 14:02, Bonita Montero wrote:
>>> I know alloca() neither is an official part of the C nor C++
>>> program-
>>> ming-language. But I use it for performance-reasons. Can anyone name
>>> compilers that don't support alloca()?
>>
>>
>> sorry, mine is not an answer but a related question
>>
>> Since when (if at any time) was variable size automatic array
>> supported ?
>>
>> I mean a temporary array local to a function whose size becomes known
>> only at runtime (seems to me a generalization of variadic functions,
>> which, too, does not know at compile time how much stack space will
>> consume).
>>
>> If implemented, It seems equivalent to alloca () ... is it there some
>> limitation then in ORDER of automatic variable creations ?
>
> There is no such limitation on your C program. The VLA can be first,
> last, or in the middle. And you can have more than one of them.
>
> Where in the activation record a compiler chooses to put it is, AFAIK,
> not specified.
>
I have QT that does not supports them, but, if sb would be
so kind to copy a minimal asm generated code for some
int Funz (int A, int B)
{
int C = 3;
int Buf [A];
int D = 2;
Buf [A-1] = B;
return (A + B * D - C);
}
int main (void)
{
return Funz (4, 3);
}
I'd like to examine the assembler generated in order to
figure out how Buf (and D, beyond it apparently) are addressed
ah, if not to annoying, TURNING OFF most if not all
optimizationz (maybe the example is too minimal to be sort
of resolved at compile time :\)
tnx in advance
--
1) Resistere, resistere, resistere.
2) Se tutti pagano le tasse, le tasse le pagano tutti
Soviet_Mario - (aka Gatto_Vizzato)
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alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 14:02 +0200
Re: alloca()-support Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-09-30 07:02 -0700
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 16:09 +0200
Re: alloca()-support Bo Persson <bo@bo-persson.se> - 2019-09-30 17:29 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 17:33 +0200
Re: alloca()-support gazelle@shell.xmission.com (Kenny McCormack) - 2019-09-30 16:26 +0000
Re: alloca()-support Anton Shepelev <anton.txt@g{oogle}mail.com> - 2019-09-30 17:12 +0300
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 16:16 +0200
Re: alloca()-support Anton Shepelev <anton.txt@g{oogle}mail.com> - 2019-09-30 17:30 +0300
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 16:44 +0200
Re: alloca()-support Anton Shepelev <anton.txt@gmail.com> - 2019-10-02 00:36 +0300
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 06:28 +0200
Re: alloca()-support Anton Shepelev <anton.txt@gmail.com> - 2019-10-02 16:08 +0300
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 15:42 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-09-30 14:30 +0000
Re: alloca()-support Anton Shepelev <anton.txt@g{oogle}mail.com> - 2019-09-30 17:33 +0300
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-09-30 16:56 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-09-30 15:29 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 17:31 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-01 07:03 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 10:57 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-01 18:49 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 21:20 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-10-01 20:39 +0000
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-02 04:15 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 06:28 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-02 04:29 +0000
Re: alloca()-support Keith Thompson <kst-u@mib.org> - 2019-09-30 11:14 -0700
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 18:04 +0200
Re: alloca()-support William Ahern <william@25thandClement.com> - 2019-09-30 11:01 -0700
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 07:19 +0200
Re: alloca()-support Paavo Helde <myfirstname@osa.pri.ee> - 2019-09-30 22:26 +0300
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-09-30 19:46 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 07:32 +0200
Re: alloca()-support Paavo Helde <myfirstname@osa.pri.ee> - 2019-10-01 09:08 +0300
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 08:35 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 18:48 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 18:51 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 18:55 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 18:58 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 19:53 +0200
Re: alloca()-support Keith Thompson <kst-u@mib.org> - 2019-09-30 11:13 -0700
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-09-30 19:38 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 07:41 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-10-01 15:19 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 17:31 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-01 18:58 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 21:24 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-02 04:28 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 06:30 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-02 04:36 +0000
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-02 10:01 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-02 04:42 +0000
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-02 10:10 +0200
Re: alloca()-support Mel <mel@zzzzz.com> - 2019-10-02 15:13 +0200
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-01 21:10 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 21:25 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-10-01 20:44 +0000
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-01 23:26 +0200
Re: alloca()-support Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2019-10-01 21:08 -0600
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-02 10:19 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 06:39 +0200
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-02 10:34 +0200
Re: alloca()-support Mel <mel@zzzzz.com> - 2019-10-02 15:14 +0200
Re: alloca()-support Mel <mel@zzzzz.com> - 2019-10-02 15:18 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-02 15:21 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-03 04:09 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-03 07:48 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-03 05:49 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-03 07:52 +0200
Re: alloca()-support Melzzzzz <Melzzzzz@zzzzz.com> - 2019-10-03 06:46 +0000
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-03 10:59 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-10-03 13:39 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-10-03 13:23 +0000
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-03 15:38 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-10-03 14:51 +0000
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-04 09:49 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-10-03 21:47 +0200
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-04 09:53 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-10-03 21:52 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 07:39 +0200
Re: alloca()-support James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-09-30 21:36 -0400
Re: alloca()-support Philipp Klaus Krause <pkk@spth.de> - 2019-09-30 19:14 +0200
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 19:16 +0200
Re: alloca()-support Robert Wessel <robertwessel2@yahoo.com> - 2019-10-01 00:18 -0500
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 07:43 +0200
Re: alloca()-support Keith Thompson <kst-u@mib.org> - 2019-10-01 02:42 -0700
Re: alloca()-support James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-10-01 08:11 -0400
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-10-01 14:53 +0200
Re: alloca()-support scott@slp53.sl.home (Scott Lurndal) - 2019-09-30 17:52 +0000
Re: alloca()-support Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2019-09-30 11:20 -0600
Re: alloca()-support Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-30 19:42 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 20:02 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 19:54 +0200
Re: alloca()-support Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2019-09-30 14:28 -0600
Re: alloca()-support David Brown <david.brown@hesbynett.no> - 2019-10-01 09:38 +0200
Re: alloca()-support Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-30 20:01 +0200
Re: alloca()-support Manfred <noname@add.invalid> - 2019-10-01 17:45 +0200
Re: alloca()-support Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-10-02 00:03 -0700
Re: alloca()-support Paavo Helde <myfirstname@osa.pri.ee> - 2019-10-02 11:30 +0300
Re: alloca()-support Ian Collins <ian-news@hotmail.com> - 2019-10-02 21:34 +1300
Re: alloca()-support Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-10-02 01:36 -0700
Re: alloca()-support Ian Collins <ian-news@hotmail.com> - 2019-10-02 21:41 +1300
Re: alloca()-support Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-10-02 02:28 -0700
Re: alloca()-support "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2019-10-02 02:35 -0700
Re: alloca()-support Frederick Gotham <cauldwell.thomas@gmail.com> - 2019-10-02 02:43 -0700
Re: alloca()-support Anton Shepelev <anton.txt@gmail.com> - 2019-10-02 16:26 +0300
Re: alloca()-support "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2019-10-02 12:33 -0700
Re: alloca()-support Anton Shepelev <anton.txt@gmail.com> - 2019-10-03 01:47 +0300
Re: alloca()-support "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2019-10-05 14:08 -0700
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