ref: 853823f435cd30ffb52d90cd49b4cfdba42121d4
dir: /sys/src/ape/lib/ap/386/memchr.s/
TEXT memchr(SB),$0 MOVL n+8(FP), CX CMPL CX, $0 JEQ none MOVL p+0(FP), DI MOVBLZX c+4(FP), AX CLD /* * SCASB is memchr instruction */ REPN; SCASB JEQ found none: MOVL $0, AX RET found: MOVL DI, AX SUBL $1, AX RET