ref: 9e4f84555f91cb632fb4cf84c5b445a91138aca1 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