https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70467
--- Comment #4 from Ruslan <b7.10110111 at gmail dot com> --- (In reply to Jakub Jelinek from comment #3) > ... > nothing there is able to optimize & -1 (and similarly | or ^ 0, or & 0, or | > -1). Just a note: the same happens for arithmetic operations, not just bitwise. E.g. if you change `v&=~(1ull<<63)` in the OP to `v+=1ull<<32`, GCC generates `add dword [esp],0` followed by `adc dword [esp+4],1`.
