ref: a141f4c53a32d8227f9a490a8e4f7d87445c47d1
dir: /sys/src/libc/amd64/memset.s/
TEXT memset(SB),$0 CLD MOVQ RARG, DI MOVBLZX c+8(FP), AX MOVL n+16(FP), BX /* * if not enough bytes, just set bytes */ CMPL BX, $9 JLS c3 /* * if not aligned, just set bytes */ MOVQ RARG, CX ANDL $3,CX JNE c3 /* * build word in AX */ MOVB AL, AH MOVL AX, CX SHLL $16, CX ORL CX, AX /* * set whole longs */ c1: MOVQ BX, CX SHRQ $2, CX ANDL $3, BX REP; STOSL /* * set the rest, by bytes */ c3: MOVL BX, CX REP; STOSB ret: MOVQ RARG,AX RET