From: Victor Porton <porton@narod.ru>
Subject: Re: Allocators design flaw
Date: Sat, 14 Oct 2017 19:22:26 +0300
Date: 2017-10-14T19:22:26+03:00 [thread overview]
Message-ID: <ortdkb$1umf$1@gioia.aioe.org> (raw)
In-Reply-To: lyh8v1bu5n.fsf@pushface.org
Simon Wright wrote:
> Victor Porton <porton@narod.ru> writes:
>
>> Simon Wright wrote:
>>
>>> Victor Porton <porton@narod.ru> writes:
>>>
>>>>> If the C struct needs alignment greater than that of the elements of
>>>>> which it is composed (see the AI for example) it would have it.
>>>>
>>>> "it would have it"? What this sequence of English words mean?
>>>
>>> it would have such an alignment
>>>
>>> struct chrs {
>>> char c[10];
>>> }
>>>
>>> only *needs* alignment of 1
>>>
>>> struct chrs {
>>> int last;
>>> char c[256];
>>> }
>>
>> No, all C structs share the same alignment.
>
> I agree that malloc() will always allocate aligned on some boundary
> (16-byte? 32-byte?) but that's not the same as the alignment of the
> struct itself.
>
> See e.g.
>
https://en.wikipedia.org/wiki/Data_structure_alignment#Typical_alignment_of_C_structs_on_x86
I want my program to work well with every conformant Ada compiler, not just
"typically" as you propose.
>>> needs the alignment of int (4 on this Mac)
>>>
>>> (aploogies if the C isn't correct)
--
Victor Porton - http://portonvictor.org
next prev parent reply other threads:[~2017-10-14 16:22 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-14 2:53 Allocators design flaw Victor Porton
2017-10-14 7:27 ` Dmitry A. Kazakov
2017-10-14 13:52 ` Victor Porton
2017-10-14 14:25 ` Dmitry A. Kazakov
2017-10-14 14:03 ` Victor Porton
2017-10-14 14:26 ` Dmitry A. Kazakov
2017-10-14 15:18 ` Victor Porton
2017-10-14 15:44 ` Dmitry A. Kazakov
2017-10-14 16:42 ` Victor Porton
2017-10-14 16:13 ` Simon Wright
2017-10-14 16:38 ` Victor Porton
2017-10-14 14:12 ` Victor Porton
2017-10-14 14:20 ` Victor Porton
2017-10-14 14:24 ` Victor Porton
2017-10-14 14:36 ` Dmitry A. Kazakov
2017-10-14 15:17 ` Victor Porton
2017-10-14 15:51 ` Dmitry A. Kazakov
2017-10-14 16:34 ` Victor Porton
2017-10-14 17:14 ` Dmitry A. Kazakov
2017-10-14 17:24 ` Victor Porton
2017-10-14 18:08 ` Dmitry A. Kazakov
2017-10-14 14:28 ` Dmitry A. Kazakov
2017-10-14 15:14 ` Victor Porton
2017-10-14 15:42 ` Simon Wright
2017-10-14 16:29 ` Victor Porton
2017-10-14 20:07 ` Simon Wright
2017-10-14 21:26 ` Victor Porton
2017-10-21 1:42 ` Randy Brukardt
2017-10-14 8:02 ` Simon Wright
2017-10-14 13:59 ` Victor Porton
2017-10-14 14:35 ` Simon Wright
2017-10-14 15:11 ` Victor Porton
2017-10-14 15:56 ` Simon Wright
2017-10-14 16:22 ` Victor Porton [this message]
2017-10-29 16:01 ` David Thompson
2017-10-14 14:11 ` Victor Porton
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