[FFmpeg-devel] [RFC] Loop unrolling in C code for 'vector_fmul_*' functions

Alexander Strange astrange
Mon Apr 21 07:42:45 CEST 2008


On Sun, Apr 20, 2008 at 6:52 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Sun, Apr 20, 2008 at 06:08:22PM -0400, Alexander Strange wrote:
>  [...]
>
> > The C keyword "restrict" will do this. gcc has some problems with it -
>  > it's ignored for char*, so we can't use it to fix cases like
>  > get_cabac* where char* aliasing causes a lot of unnecessary stores -
>  > but it might work here. If not, you can sometimes fix it by inlining
>  > the function into somewhere where the original definition of src/dst
>  > are both visible.
>
>  Has the issue you describe been reported to the gcc devels by someone?

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33705 but I only renamed
it to the real problem just now.
In that case it's not hard to work around it, I started but never finished it.




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