https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63783
--- Comment #15 from Michael Karcher <gcc-bugzilla at mkarcher dot dialup.fu-berlin.de> --- I did not get around to test your proposed patch yet, but it seems like the new "logical not" operation always compares only the low 32 bit against zero, even if there is a 64 bit operand. If my analysis is correct, the long long test program should fail if you replace "decision = 1;" by "decision = 0x100000000LL;"