ref: b86bb35c7d82f097e6572d400527046245b877fd 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