https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69624
--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Seems hweight.c is compiled with -fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11 but that of course expects that all the functions in there are leaf, if they aren't leaf, you'd need to compile with the same flags also all the functions that might be called from there. So bet you want to arrange for hweight.c from being compiled without -fsanitize-coverage=trace-pc and without other options that might introduce calls.
