[FFmpeg-devel] [PATCH] read_time() for SPARC

Michael Kostylev michael.kostylev
Fri Sep 10 11:32:07 CEST 2010

On Fri Sep 10 09:47:34 2010
M?ns Rullg?rd wrote:

>>>>>> if the only issue left is the sometimes unneeded stx instruction
>>>>>> then i approve the patch with this. If there are other issues they
>>>>>> of course have to be fixed first
>>>>>Apparently the ifdef test in the patch is not reliable.
>>>> Redone.
>>>> Michael
>>>> +#ifndef AVUTIL_SPARC_TIMER_H
>>>> +#define AVUTIL_SPARC_TIMER_H
>>>> +
>>>> +#if defined(__arch64__) || defined(__sparc_v9__)
>>>I'm still not convinced this is right:
>> There is an issue with -m32 on Solaris.
>I don't understand.

As mentioned, __sparc_v9__ is never defined there.

>>>$ sparc-unknown-linux-gnu-gcc -m32 -mcpu=v9 -mno-v8plus -dM -E -xc /dev/null | grep -E 'arch|sparc'
>>>#define sparc 1
>>>#define __sparc__ 1
>>>#define __sparc 1
>>>#define __sparc_v9__ 1
>> This is as right as xor rax,rax in an i386 binary built with -march=core2.
>Yes, that instruction would be invalid there.  In a pure 32-bit
>environment, you can't use the high half of 64-bit registers, even if
>they are physically present.  Consider what happens on a context switch.

An ancient kernel will not preserve the sse registers as well. Anyway, there
is no such problem on Sparc. Anything else?


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