This patch has been committed to the master branch: https://gcc.gnu.org/pipermail/gcc-patches/2021-April/569135.html https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=6efd040c301b06fae51657c8370ad940c5c3d513 Learn more about Built-in Functions about Performing Arithmetic with Overflow Checking: https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html Since these functions are pervasively used in the kernel, driver, etc. Adding patterns to the RISC-V backend should allow us to have some performance elevation. Some example: https://android.googlesource.com/kernel/common.git/+/refs/tags/ASB-2019-03-05_4.9/include/linux/overflow.h https://lwn.net/Articles/623368/ Let’s start with… Read more [GCC] RISC-V: Add patterns for builtin overflow.