[FFmpeg-devel] [PATCH 7/7] Add alias-safe aligned AV_[RW]N macros

[Måns Rullgård]

Reimar D?ffinger <Reimar.Doeffinger at gmx.de> writes:

> On Fri, Feb 05, 2010 at 10:51:59AM +0100, Michael Niedermayer wrote:
>> On Sun, Jan 31, 2010 at 02:08:29AM +0000, M?ns Rullg?rd wrote:
>> > Michael Niedermayer <michaelni at gmx.at> writes:
>> > 
>> > > On Fri, Jan 29, 2010 at 02:12:14AM +0000, Mans Rullgard wrote:
>> > >> ---
>> > >>  libavutil/intreadwrite.h |   32 ++++++++++++++++++++++++++++++++
>> > >>  1 files changed, 32 insertions(+), 0 deletions(-)
>> > >> 
>> > >> diff --git a/libavutil/intreadwrite.h b/libavutil/intreadwrite.h
>> > >> index 631db75..61ad488 100644
>> > >> --- a/libavutil/intreadwrite.h
>> > >> +++ b/libavutil/intreadwrite.h
>> > >> @@ -418,6 +418,38 @@ union unaligned_16 { uint16_t l; } __attribute__((packed)) av_alias;
>> > >>      } while(0)
>> > >>  #endif
>> > >>  
>> > >> +/*
>> > >> + * The AV_[RW]NA macros access naturally aligned data
>> > >> + * in a type-safe way.
>> > >> + */
>> > >> +
>> > >> +#define AV_RNA(s, p)    (((const ff_alias##s*)(p))->u##s)
>> > >> +#define AV_WNA(s, p, v) (((ff_alias##s*)(p))->u##s = (v))
>> > >
>> > > do we really need yet another set?
>> > 
>> > We need one set for aligned accesses and one for unaligned, yes.
>> 
>> yes i agree, doesnt mean i like it though
>
> What I don't particularly like is that "NA" is a bit confusing, unless
> you extrapolate from the other naming it might just as well mean "not aligned".
> No, I don't have better ideas...

We could rename the other ones into AV_[RW]*U...

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