[Ffmpeg-devel] int vs. float: Hard Numbers
Fri May 20 21:17:10 CEST 2005
Michael Niedermayer wrote:
> if it where so simple ...
> but it isnt, the code is flawed and wont tell you much usefull
> the first problem is that its all executed just once, so the code wont be in
> the code cache, practically no speed critical piece of code would be executed
> just once ...
Could we mitigate this problem by "warming up" the cache by running the
function 1000 times and then profiling run #1001?
> the second problem is that every instruction uses the result of the previous,
> while this gives one interresting value for comparission we should also
> meassure how fast cpus are if the instructions dont depend upon each other
I wanted to stay away from memory accesses, naturally. So, how about a
series of instructions that rotated between using different registers so
that the CPU could perhaps re-order the instructions during execution?
More information about the ffmpeg-devel