[FFmpeg-soc] [soc]: r5419 - als/alsdec.c

[Thilo Borgmann]

Michael Niedermayer schrieb:
> On Thu, Oct 22, 2009 at 11:29:55AM +0200, Thilo Borgmann wrote:
>> Thilo Borgmann schrieb:
>>> Michael Niedermayer schrieb:
>>>> On Wed, Oct 21, 2009 at 12:33:21PM +0200, Thilo Borgmann wrote:
>>>>> Michael Niedermayer schrieb:
>>>>>> On Tue, Oct 20, 2009 at 03:00:40PM +0200, thilo.borgmann wrote:
>>>>>>> Author: thilo.borgmann
>>>>>>> Date: Tue Oct 20 15:00:40 2009
>>>>>>> New Revision: 5419
>>>>>>>
>>>>>>> Log:
>>>>>>> Splits reading of block data and decoding of block data.
>>>>>>> Introduces ALSBlockData struct.
>>>>>> You are missing the "why" part, that should be explained in the commit
>>>>>> message
>>>>> Yes, sorry.
>>>>>
>>>>>> also this needs a benchmark as there are many additional dereferences
>>>>>> added
>>>>> It is a necessary evil to support MCC. If it would be faster the "old"
>>>>> way for non-MCC files, would this reason to have both, a split read &
>>>>> decode function pair and an all-in-one function?
>>>> I think a benchmark is usefull to judge if we should spend time thinking
>>>> about alternatives to the many dereferences or not
> [...]
>>> This is a 30% difference which makes me think to try these alternatives.
>>>
>>> What comes into my mind would be to use local copies, thus dereferencing
>>> the field of *bd just twice. One at the top and one at the bottom of the
>>> function.
>>>
>> I tested using local copies instead of dereferencing:
> [...]
>> That's a 4% gain so I think local copies don't pay off...
>>
>> Other alternatives?
> 
> i would first confirm that gcc did not do something stupid about inlining.
> Or more precissely not inlining some random unrelated function after the
> file got bigger ...

How to do that?