Enabling basic block profiling information

[Mohamed Shafi]

Hello all,

Previously -a option was used to generate extra code to write profile
information for basic blocks. But this options has been replaced with
-fprofile-arcs. According to gprof.info

"   In addition to the `-pg' and `-g' options, older versions of GCC
required you to specify the `-a' option when compiling in order to
instrument it to perform basic-block counting.  Newer versions do not
require this option and will not accept it; basic-block counting is
always enabled when `-pg' is on. "

But compiling a code similar to the one given as a example in
gprof.info and using gporf i am not getting any basic block profiling
info.This is what i did

a) $ gcc -g -pg 1.c

After executing

b) gprof -i

c) gprof -l -A -x > output.gmon

This is not providing any basic block profiling information.
Do i need to enable some other option during compilation of the program?
Or is it that gprof doesn't produce any basic block profiling information?
Am i missing something?

Thanks for your time.

Regards,
Shafi