https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84772
--- Comment #4 from Zack Weinberg <zackw at panix dot com> --- The last actual _change_ in my GCC build is r258315 | denisc | 2018-03-07 04:13:12 -0500 (Wed, 07 Mar 2018) | 9 lines Backport from mainline 2018-02-07 Georg-Johann Lay <a...@gjlay.de> PR target/84209 * config/avr/avr.h (GENERAL_REGNO_P, GENERAL_REG_P): New macros. * config/avr/avr.md: Only post-reload split REG-REG moves if either register is GENERAL_REG_P.