https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87376
--- Comment #7 from Georg-Johann Lay <gjl at gcc dot gnu.org> --- I have no idea how to fix this one. The problem is that the DImode move is being expanded into 8 x QImode loads from memx, and there is no way to do stuff similar to PR115726 because we do not have movdi insns. We have to deal with hard regs in expand due to -ftree-ter, hence he aforementioned -fno-tree-ter can be used as a work-around.
