ref: cd6f51e699e261ce5d12163269d7e01ecb26ca11 dir: /memsetl-amd64.s/
TEXT _memsetl(SB),1,$0 CLD MOVQ RARG, DI MOVL c+8(FP), AX MOVQ n+16(FP), CX REP; STOSL MOVQ RARG,AX RET