[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: How to correctly determine a small object?
From: |
David Chisnall |
Subject: |
Re: How to correctly determine a small object? |
Date: |
Sat, 8 Jun 2013 18:28:34 +0100 |
No. See the email you replied to for why not.
David
On 8 Jun 2013, at 18:20, Maxthon Chan <address@hidden> wrote:
> So I can safely do this? (Macro rewritten as inline function)
>
> static inline __attribute__((always_inline)) BOOL objc_isSmallObject(id obj)
> {
> return (((intptr_t)obj) & 1) ? YES : NO;
> }
>
> 在 2013-6-8,上午4:10,David Chisnall <address@hidden> 写道:
>
>> On 7 Jun 2013, at 16:29, Luboš Doležel <address@hidden> wrote:
>>
>>> for toll-free bridging in CoreBase, I need a way to detect whether the
>>> incoming pointer is a small object encoded in a pointer and act accordingly
>>> (treat it as an ObjC object and avoid reading it).
>>
>> In objc/runtime.h, there is a constant SMALL_OBJECT_MASK. If ptr &
>> SMALL_OBJECT_MASK == 0, then the pointer is not a small object.
>>
>> On 32-bit platforms, the low bit of the pointer will be 0. On 64-bit
>> platforms, the low 3 bits will always be zero.
>>
>> David
>>
>>
>> _______________________________________________
>> Gnustep-dev mailing list
>> address@hidden
>> https://lists.gnu.org/mailman/listinfo/gnustep-dev
>
>
> _______________________________________________
> Gnustep-dev mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/gnustep-dev
--
This email complies with ISO 3103
- How to correctly determine a small object?, Luboš Doležel, 2013/06/07
- Re: How to correctly determine a small object?, Stefan Bidi, 2013/06/07
- Re: How to correctly determine a small object?, David Chisnall, 2013/06/07
- Re: How to correctly determine a small object?, David Chisnall, 2013/06/07
- Re: How to correctly determine a small object?, Luboš Doležel, 2013/06/08
- Re: How to correctly determine a small object?, Maxthon Chan, 2013/06/08
- Re: How to correctly determine a small object?,
David Chisnall <=
- Re: How to correctly determine a small object?, Chan Maxthon, 2013/06/08
- Re: How to correctly determine a small object?, Ivan Vučica, 2013/06/08
- Re: How to correctly determine a small object?, Chan Maxthon, 2013/06/08
- Re: How to correctly determine a small object?, Ivan Vučica, 2013/06/08
- Re: How to correctly determine a small object?, Chan Maxthon, 2013/06/08
- Re: How to correctly determine a small object?, David Chisnall, 2013/06/09
- Re: How to correctly determine a small object?, Graham Lee, 2013/06/09
- Re: How to correctly determine a small object?, Graham Lee, 2013/06/09
- Re: How to correctly determine a small object?, Maxthon Chan, 2013/06/09
- Re: How to correctly determine a small object?, David Chisnall, 2013/06/09