[FFmpeg-cvslog] r18896 - trunk/libavcodec/eatgq.c
Sat May 23 17:25:11 CEST 2009
Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:
> On Fri, May 22, 2009 at 10:27:35PM +0100, M?ns Rullg?rd wrote:
>> reimar <subversion at mplayerhq.hu> writes:
>> > Author: reimar
>> > Date: Fri May 22 20:39:00 2009
>> > New Revision: 18896
>> > Log:
>> > Move eatgq blocks array from the stack to the codec context and make sure
>> > it is aligned as necessary for DSPContext's idct_put.
>> > Just aligning it on the stack would have been possible but less reliable
>> > and without any real benefit.
>> Aligning for idct on the stack is *not* possible. It may work by
>> accident most of the time, but DO NOT RELY ON IT.
> Given we have added gcc attributes to realign the stack etc. I conclude
> that someone somewhen wanted it to be possible,
Wanting something does not make it so.
> and I'm not sure you have to rely on "accident" for it to work with
> gcc/Linux at least.
We support a multitude of compilers and operating systems, several of
which DO NOT SUPPORT aligning stack variables to more than 8 bytes.
> So it seems to me that the commit message is quite accurate, even if
> we might want to avoid aligned data on the stack completely in the
Aligning stack variables is either possible or impossible. Unreliable
is equivalent to impossible. The commit message is misleading.
mans at mansr.com
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