https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63440
--- Comment #2 from R. Diez <rdiezmail-gcc at yahoo dot de> --- Yes, I would enable -fmerge-constants with -Og. I would do it even for -O0. Merging constants should be safe, and it saves precious program space when generating debug builds for small embedded targets. Besides, in my opinion, it does not make sense that the addresses of some literal strings suddenly change when you enable optimisations, because they get collapsed. Any bugs because of such shared addresses should be apparent in debug builds too. Note that GCC already seems to apply some optimisations when building with -O0. Specifically, I believe that at least some dead code elimination does occur. That would make sense, as you do not want to bloat your debug builds unnecessary.
