> > -fno-builtin is good, but you cannot use it in an optimize attribute. > > This is quite confusing since for other optimiziations in this area it works like that, e.g. glibc (include/libc-symbols.h): Since I already answered this previously here in the list, I added it to the wiki: https://gcc.gnu.org/wiki/FAQ#optimize_attribute_broken The explanation could be better, perhaps more detailed and nuanced, thus I encourage others to improve it. Cheers, Manuel.
