Those functions are not referencing each other, but they get used in different logical groups, so at least control granularity can be improved. For instance, 1) all gcov user interfaces such as gcov_dump, gcov_flush, gcov_reset are either not used at all, or all of them are used -- there is no need to split this group. After Rong's refactoring (move them into a separate file), the guarding macro can be removed for them 2) _gcov_merge_add is used by 4 different profilers, so it is almost always linked in
It is unclear how other value profilers are used on other targets. For x86, they are on by default, so the profiler bodies and merge functions are also always linked in. David On Tue, Nov 5, 2013 at 1:23 AM, Jakub Jelinek <ja...@redhat.com> wrote: > On Tue, Nov 05, 2013 at 10:18:50AM +0100, Jan Hubicka wrote: >> > I wonder if it makes sense to get rid of the conditional compile such as >> > >> > #ifdef L_gcov_xxxxx >> > .. >> > >> > #endif >> > >> > This has the advantage of producing slightly smaller instrumented >> > binary, but this benefit can also be achieved via -ffunction-sections >> > and let linker to garbage collect unused functions. >> > >> > (probably as a follow up if it makes sense). >> >> I believe we use this funny scheme primarily for targets that have no >> function >> section support (and also the hand made splitting can be more sane). >> For a low-level library like libgcov is that is supposed to have small >> footprint, >> I guess the current scheme is resonable thing to do.... > > I think the #ifdef L* stuff is there mainly so that we have small > granularity in the *.a libraries (one function per object file), so that one > links only what is really required (at least, that is why libgcc.a does > that). Of course, if there are many interdependencies between the functions > and you always essentially link in everything, the usefulness of that is > lower. > > Jakub
