do -fprofile-arcs and -fbranch-probabilities help to set bb->count?

[Liu Haibin]

Hi,

I wanted to use bb->count, so I expected that -fprofile-arcs and
-fbranch-probabilities would help. I added printf just before
peephole2 optimization and ran the following.

$gcc -O3 -fprofile-arcs test.c -o test
$./test (which produced test.gcno only, but no test.gcda)
$gcc -O3 -fprofile-arcs -fbranch-probabilities test.c -o test

But it turned out that all the basic block counts were 0. Any idea how
I can see bb->count set.


Regards,
Haibin