http://www.emulators.com/docs/LazyOverflowDetect_Final.pdf http://www.emulators.com/docs/LazyOverflowDetect_Final.pdf This paper seems to imply that that high l

http://www.emulators.com/docs/LazyOverflowDetect_Final.pdf http://www.emulators.com/docs/LazyOverflowDetect_Final.pdf This paper seems to imply that that high level languages can't access the carry bit, yet C#'s checked mechanism uses it. I've been using -ftrapv with gcc for a long time, from here: https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options. From the code you posted, and the assembly[1] emitted in the pdf above I can't see the optimiser taking advantage of the carry bit. No mention of CF, OF: [1] lea ebx, DWORD PTR [edi+eax] cmp ebx, edi jae SHORT $LN4@unsigned_c cmp ebx, eax jae SHORT $LN4@unsigned_c mov ecx, 1 jmp SHORT $LN5@unsigned_c xor ecx, ecx The gcc flag ftapv only works for signed integers, not clear what the carry bit behaviour is for unsigned integers.