[FFmpeg-devel] [PATCH] configure: add host libm capability detection

Hendrik Leppkes h.leppkes at gmail.com
Thu Nov 26 14:50:58 CET 2015

On Thu, Nov 26, 2015 at 2:10 PM, Ganesh Ajjanagadde <gajjanag at mit.edu> wrote:
> On Thu, Nov 26, 2015 at 2:49 AM, Hendrik Leppkes <h.leppkes at gmail.com> wrote:
>> On Thu, Nov 26, 2015 at 6:04 AM, Ganesh Ajjanagadde
>> <gajjanagadde at gmail.com> wrote:
>>> This is needed in order to obtain what is available for hardcoded
>>> table generation.
>>> A minimal avutil/host_libm.h is also created.
>> I'm really not a fan of this change. configure is slow and complex
>> enough as it is, and host tools don't need to be micro-optimized,
>> since they are never run by a user.
> 1. I deliberately kept the host_math_func list very short because I
> recognized this concern regarding configure's slowness.
> 2. They are run by a lot of users, since tablegen is done at runtime
> by default. "Never run by a user" is thus incorrect. It is not a
> "micro-optimization", pow is often 4x slower than relevant function.

These things are for host code, that is not run by users.

- Hendrik

More information about the ffmpeg-devel mailing list