On 23 May 2016 at 12:37, Ons Boutiti wrote: > Hi all, > I have read about gcc builtin functions and its utility, I would ask > some basic questions: how can I implement a new built-in function into > gcc?! It depends what you want the function to do. > is there a manual or an exemple to follow it because i just > found definitions. I added the C++ __is_final builtin with the patch attached to https://gcc.gnu.org/ml/gcc-patches/2011-12/msg00231.html -- that might give you some hints about how to extend the compiler to recognise a new builtin function, but you'll still need to implement its functionality yourself.