ref: e0720a48b0ce9db78aa1e048e4e2d1d5cfae41db
dir: /sys/src/libc/68000/strchr.s/
TEXT strchr(SB), $0 MOVL s+0(FP), A0 MOVB c+7(FP), R2 BEQ null l: MOVB (A0)+, R1 BEQ out CMPB R1, R2 BNE l MOVL A0, R0 ADDL $-1, R0 RTS out: CLRL R0 RTS null: TSTB (A0)+ BNE null MOVL A0, R0 ADDL $-1, R0 RTS