GProf's sampling inaccuracies

[Segher Boessenkool]

> When I run the
> program with profiling on the build I get 5743514 calls to
> CompareReferences() in the flat profile.

Please make sure the asm code in your actual binary is the
same as you think it is; run  objdump -drS  on the .o file
or your resulting executable.

> When I run it with profiling just on
> the link, the self-seconds are: 1.85. This comes to an average of 
> 322ns/call.
> How do we explain that? Do we conclude that those 5743514 calls to 
> movl and
> 5743514 calls to cmpl where all cache misses?

Dunno.  You might want to look at using a more fine-grained
profiler instead, that can use your CPU's profiling extensions,
like Oprofile on Linux.


Segher