https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100342
--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> --- The problematic insn is: 401cec: 44 89 f6 mov %r14d,%esi This one should be 64 bit wide, movl %r14d, %esi # 613 [c=4 l=3] *movqi_internal/2 but is actually a QImode move from r14 to esi.