@LisPi @Sally (evil) @Alexandre Oliva it's not compiler intrinsics. Linux the kernel uses language constructs that aren't a part of the standard.

Again, the C spec is mostly useless except when the compiler authors implement some peculiar UB that is only designed to shoot programmers in the foot while providing no real value otherwise. Not only that, but there have been cases where MSVC and GCC behaviour diverged while both technically being standard compliant. Because the C standard is written by a bunch of anal-retentive retards.