https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59874
--- Comment #3 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Manuel Lauss from comment #2) > I've run into this issue with current gcc-6-branch while building for > example qt-5.7. gcc-5-branch can build this source just fine: __builtin_clzs and __builtin_ctzs are internal x86 builtins and were recently removed. You should use __lzcnt16 and __tzcnt_u16 intrinsics. > return v ? __builtin_ctzs(v) : 16U; > return v ? __builtin_clzs(v) : 16U; You don't need this, the instruction does exactly the above.
