https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109236
Dimitar Dimitrov <dimitar at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |dimitar at gcc dot gnu.org --- Comment #1 from Dimitar Dimitrov <dimitar at gcc dot gnu.org> --- Pass the -Wstrict-overflow=4 option to GCC and see that compiler assumes no integer overlow will happen: test.c:3:12: warning: assuming signed overflow does not occur when simplifying 'X - Y <= 0' to 'X <= Y' [-Wstrict-overflow] 3 | return (x-y <= 0); Consider using "__builtin_sub_overflow" for a strictly defined behaviour when integer overflow happens.