ref: 4d0343c9d2db502c162f5050385ba5528aef2a47 dir: /sys/src/libc/386/strlen.s/
TEXT strlen(SB),$0 MOVL $0, AX MOVL $-1, CX CLD /* * look for end of string */ MOVL p+0(FP), DI REPN; SCASB MOVL DI, AX SUBL p+0(FP), AX SUBL $1, AX RET