[mythtv] Compiler opt flags

Gregorio Gervasio Jr. gtgj at pacbell.net
Fri May 16 00:45:28 EDT 2003


>>>>> On Fri, 16 May 2003 06:52:31 +0200, Ben Bucksch <linux.news at bucksch.org> said:

[...]

b> But more importantly, it seems to me that avcodec and avformat, which
b> are used to compress the video and do the actual hard and
b> CPU-intensive work (right?), don't use these flags. The only opt flag
b> I noticed was -O3, no CPU opt. The step from -march=pentium to
b> -march=pentiumpro can mean 5-10% performance increase (tested with gcc
b> 2.95 and Mozilla), so it seems significant, esp. considering that you
b> build the rest of MythTV with those flags anyways.

For libavcodec, you can do it by running:

./configure --extra-cflags="-march=athlon -O6"

or whatever you want, but as Isaac said, the critical stuff in MythTV
is already in MMX.  Personally, I don't notice much of a difference
over "-O -g" so the latter is what I use so I don't have to recompile
to get a backtrace.
-- 
Gregorio Gervasio, Jr.
gtgj at pacbell.net


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