Use -fprofile-generate get basic block counts

[Jianzhang Peng]

Hi, all

I want to know every instructions  an application runs.

So  , first , I need to konw every basic blocks'  frequency.
I'd like to use -fprofile-generate and -fprofile-use get basic block counts.
As GCC collect the profile information at pass-tree-profile,
I wander  whither the instrumentation may restrict some optimization?

For example:
gcc  -fprofile-generate -O3  foo.c  -o foo

gcc   -O3  foo.c  -o  bar

Dose "foo" and "bar" are equally  optimized?

thanks!
-- 
Jianzhang Peng