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

Måns Rullgård mans
Thu Sep 9 20:00:56 CEST 2010


Michael Kostylev <michael.kostylev at gmail.com> writes:

> On Thu Sep  9 12:15:05 2010
> M?ns Rullg?rd wrote:
>
>>>>>> The presence of __sparc_v9__ clearly does not imply we are allowed
>>>>>> to use 64-bit registers; __arch64__ does.
>>>>>
>>>>> __sparc_v9__ means the v9 hardware, __arch64__ means the v9 abi.
>>>>
>>>>Exactly, and without the v9 ABI we can't use 64-bit registers.
>>>
>>> We can with v8+ and we do.
>
> "SPARC V8PLUS ABI Restrictions
> [...]
> The rest of the register restrictions remain unchanged from SPARC V8 ABI.
> However, the global registers are 64-bit registers and may be used as such
> by user programs."

Please explain the meaning of "global register".

>>Absurd, and gcc appears to disagree.
>
> If it does not use the 64-bit general regs when it is meaningful then gcc
> sucks.

That would hardly be a surprise.

Anyhow, the memory store in your patch is clearly not needed in some
configurations.  We should detect these and use the efficient way there.

-- 
M?ns Rullg?rd
mans at mansr.com



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