[FFmpeg-soc] Tips From The Hardened FFmpeg Veterans

[Reimar Döffinger]

On Wed, May 07, 2008 at 02:25:07AM +0000, compn wrote:
> Mike Melanson <mike at ...> writes:
> > * ccache (ccache.samba.org): This tool caches your compiled object
> > * valgrind (valgrind.org): Memory checker tool; it will point out when
> > These are the first 2 things I can think of. Other veterans, please jump in.
>  
> 
> as i'm sure michael will find slow/unoptimized code , dont forget start/stop 
> timer.

For larger amounts of code, oprofile (http://oprofile.sourceforge.net/docs/) can be
quite useful, too.
Also useful for optimizing is looking directly at what kind of mess the
compiler made this time.
gcc -S -o or objdump are good if AT&T syntax is fine for you. Otherwise
I can also recommend http://hte.sourceforge.net/ esp. since it comes
with an included assembler so you can also quickly hack things.
For debugging symbol/code sizes (probably less important in these cases)
I use a shell script with this:

objdump -t "$1" | grep "$2" | awk '{ print $5"   "$6 }' | sort | less

First argument to the script is the name of the binary, second argument
is whatever you are looking for - e.g. a symbol name or "rodata" if
you want to look what is in the read-only data section.

Greetings,
Reimar Döffinger