https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65534
--- Comment #3 from Bernhard Reutner-Fischer <aldot at gcc dot gnu.org> --- (In reply to Bernhard Reutner-Fischer from comment #2) > (In reply to Jan Hubicka from comment #1) > > > #ifndef OPTIMIZE_MANUALLY > > > void setutent(void) { > > > ((void)0); > > > __setutent_unlocked(); > > > ((void)0); > > > } > > > #else > > > extern __typeof (__setutent_unlocked) setutent > > > __attribute__ ((alias ("__setutent_unlocked"))); > > > #endif > > > > I do not think GCC can safely optimize this, becuase in the first > > case &setutent != &__setutent_unlocked, wile in the optimized > > case the addresses are equal. > > Note that __setutent_unlocked is static, so i don't see how this specific > case would prevent optimization? gcc-6 stage1 passed. Honza, please explain how'd that prevent optimization?