https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85473
H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2018-04-19 Ever confirmed|0 |1 --- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- movdir64 stores 64 byte. But it doesn't show: (define_insn "movdir64b_<mode>" [(unspec_volatile:SWI48[(match_operand:SWI48 0 "register_operand" "r") (match_operand:SWI48 1 "memory_operand")] UNSPECV_MOVDIR64B)] "TARGET_MOVDIR64B" "movdir64b\t{%1, %0|%0, %1}" [(set_attr "type" "other")]) Here register is used as address.