The following two patches fix PR 77822 on s390x for gcc-7. As the macro doing the argument range checks can be used on other targets as well, I've put it in system.h (couldn't think of a better place; maybe rtl.h?).
Bootstrapped on s390x biarch, regression tested on s390x biarch and s390, all on a zEC12 with -march=zEC12. Please check the commit messages for details. Ciao Dominik ^_^ ^_^ -- Dominik Vogt IBM Germany