[FFmpeg-devel] [RFC] support encrypted asf

[Reimar Döffinger]

Hello,
On Tue, Oct 09, 2007 at 02:06:26PM +0200, Michael Niedermayer wrote:
[...]
> actually the following would in theory be better
> 
> static uint_fast32_t inverse4(uint_fast32_t v) {
>     uint_fast32_t i = v * v * v;
>     i *= 2 - v * i;
>     i *= 2 - v * i;
>     i *= 2 - v * i;
>     return i;

In practice it results in about 30 % larger code (1 byte per instruction
more) on x86_64 without (measurable) changes in speed.
This is admittedly due to *fast* types being implemented as a fixed
typedef at least for gcc, making them quite useless on x86 at least.

Greetings,
Reimar D?ffinger