You could implement them as static/inline functions for compilers that lack the builtins (using a bunch of comparisons with SHORT_/INT_MAX, ...) , which would b

You could implement them as static/inline functions for compilers that lack the builtins (using a bunch of comparisons with SHORT_/INT_MAX, ...) , which would be slower but for things explicitly meant as security check, probably worth the cost. I've used them to replace explicit checks for overflow in some DSP related code which tried to implement saturation. The gcc builtins also were much faster than tedious "manual" checks.