+ Rasmus This was introduced in commit f0907827a8a91 ("compiler.h: enable builtin overflow checkers and add fallback code") which added division using the `/` operator, which is problematic when checking for overflows of 64b operands on 32b targets. We'll probably need helpers from linux/math64.h and some combination of __builtin_choose_expr/__builtin_types_compatible_p. That will help us fix another compiler bug for older clang releases, too. https://github.com/ClangBuiltLinux/linux/issues/1438.