[Mesa-dev] [PATCH] mesa: Fix test for big-endian architecture in compiler.h

[Oded Gabbay]

On Mon, Feb 15, 2016 at 8:33 PM, Jochen Rollwagen <joro-2013 at t-online.de> wrote:
> Am 15.02.2016 um 15:53 schrieb Oded Gabbay:
>>
>> Sent with MailTrack
>>
>> On Sat, Feb 13, 2016 at 2:39 AM, Roland Scheidegger <sroland at vmware.com>
>> wrote:
>>>
>>> Am 12.02.2016 um 10:01 schrieb Jochen Rollwagen:
>>>>
>>>> Hi,
>>>>
>>>> i think i found & fixed a bug in mesa concerning tests for big-endian
>>>> machines. The defines tested don't exist or are wrongly defined so the
>>>> test (probably) never fires. The gcc defines on my machine concerning
>>>> big-endian are
>>>>
>>>> jochen at mac-mini:~/sources/mesa$ gcc -dM -E - < /dev/null | grep BIG
>>>> #define __BIGGEST_ALIGNMENT__ 16
>>>> #define __BIG_ENDIAN__ 1
>>>> #define __FLOAT_WORD_ORDER__ __ORDER_BIG_ENDIAN__
>>>> #define _BIG_ENDIAN 1
>>>> #define __ORDER_BIG_ENDIAN__ 4321
>>>> #define __BYTE_ORDER__ __ORDER_BIG_ENDIAN__
>>>>
>>>> The tested values in current mesa are quite different :-)
>>>>
>>>> The following patch fixes this.
>>>>
>>>> diff --git a/src/mesa/main/compiler.h b/src/mesa/main/compiler.h
>>>> index c5ee741..99c63cb 100644
>>>> --- a/src/mesa/main/compiler.h
>>>> +++ b/src/mesa/main/compiler.h
>>>> @@ -52,7 +52,7 @@ extern "C" {
>>>>    * Try to use a runtime test instead.
>>>>    * For now, only used by some DRI hardware drivers for color/texel
>>>> packing.
>>>>    */
>>>> -#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER ==
>>>> BIG_ENDIAN
>>>> +#if defined(__BYTE_ORDER__) && defined(__BIG_ENDIAN__) &&
>>>> __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
>>>>   #if defined(__linux__)
>>>>   #include <byteswap.h>
>>>>   #define CPU_TO_LE32( x )       bswap_32( x )
>>>>
>>> Note that on some platforms this file would include endian.h - which
>>> defines those BYTE_ORDER etc. values. Albeit it includes this _after_
>>> these ifdefs...
>>> But don't ask me how this is really supposed to work...
>>>
>>> Roland
>>
>> <stdlib.h> includes <bits/waitstatus.h> which includes <endian.h>
>>
>> However, this depends on the c/h files to include <stdlib.h> before
>> including "compiler.h", which doesn't always happen (e.g
>> dummy_errors.c) and it is a very fragile situation.
>>
>> So I think this is a good fix and this patch is:
>> Reviewed-by: Oded Gabbay <oded.gabbay at gmail.com>
>>
>> Jochen,
>>
>> Note that I downloaded this patch from pw and it was malformed. I
>> don't know if its a pw problem or a problem in how you sent the patch
>> to the ml.
>>
>>      Oded
>>
>>
>>>
>>> _______________________________________________
>>> mesa-dev mailing list
>>> mesa-dev at lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
> Well, i just copied it from the git-diff-terminal and pasted it into my
> mail-client. Maybe a newline problem ? Anyway, i attached the patch (and
> patched my local mesa with it before, which worked :-) ).
>
> Cheers
>
> Jochen

Hi Jochen,
This is just a plain patch and not a commit (created by git).
Do you want to create a proper commit and send it (using git-send) or
do you want me to do it for you ? Of course I'll keep you as author.

Thanks,

     Oded