Re: Makefile and gprof problem

[RS]

Paul Pluzhnikov wrote:
> RS <rsina_no.ssppaamm@comcast.net> writes:
>
> > So my question is 1) why the program compiles,links and runs
> > correctly, but the name of the functions look so weired?
>
> They only look weird because you dont't understand a pretty
> fundamental concept: name mangling. Read about it here:
>
> http://en.wikipedia.org/wiki/Name_mangling

Thanks very much for the pointer

> > 2) why the total and self times show to be 0.00?
> > The program takes 15 minutes
>
> The 15 minutes are probably spent in system (dynamic) libraries,
> or waiting for the OS. What does "time ./a.out" say?

In the abbreviated version of the code, the output of "time ./program" is

real    0m57.768s
user    0m40.878s
sys     0m7.812s

For the same abbreviated code, gprof claims that both the total time and 
self time of all the functions (including main) are 0.0. So I guess I 
don't understand the fundamental thing about gprof, because I thought I 
could get some idea of how much time is spent in each function


> If the program mostly waits for the OS (system and user time low,
> wall clock time high), then you can study output of 'strace -T
> ./a.out' (or whatever its equivalent on OSX is).
>
> If user time is high, then your program spends most of its time in
> system libraries, and you need to find -pg versions of them. Best
> to ask on Apple-specific groups about profiling such libraries.

The (static) library, libfoo.a, that I link with, is my own defined 
library, which I have put all the functions in. It is not a system 
library. Are you saying that gprof can not go into the libraries? I 
tried to link the object files directly to mt main function instead of 
using a library. But I still get the same result (e.g. the total time 
spent in main function is still 0.0).

Happy Holidays,
RS