https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78994
--- Comment #7 from PeteVine <tulipawn at gmail dot com> --- Not affected by -mno-fix-cortex-a53-843419 which gives the issue full validity. -Ofast pessimizes Cortex A53 codegen somehow and switching to e.g. -mcpu=cortex-a57 fixes it. (tested on trunk)