Function __gcov_indirect_call_profiler_atomic (which contains call to the atomic function) is always emitted in libgcov. Since we only link libatomic when -fprofile-gen-atomic is specified, we have to make the atomic function weak -- otherwise, there is a unsat for regular FDO gen build (of course, when the builtin is not expanded).
An alternative it to always link libatomic together with libgcov. Then we don't need the weak stuff. I'm not sure when one is better. -Rong On Mon, Jan 7, 2013 at 12:36 PM, Richard Henderson <r...@redhat.com> wrote: > On 01/03/2013 04:42 PM, Rong Xu wrote: >> It links libatomic when -fprofile-gen-atomic is specified for FDO >> instrumentation build. Here I assume libatomic is always installed. >> Andrew: do you think if this is reasonable? >> >> It also disables the functionality if target does not support weak >> (ie. TARGET_SUPPORTS_WEAK == 0). > > Since you're linking libatomic, you don't need weak references. > > I think its ok to assume libatomic is installed, given that the > user has had to explicitly use the command-line option. > > > r~
