ref: f86cc3e912e1598ff0df63b053dcb49b24e7f758 dir: /sys/src/libc/68000/tas.s/
TEXT _tas(SB), $0 MOVL $0, R0 MOVL a+0(FP), A0 TAS (A0) BEQ tas_1 MOVL $1, R0 tas_1: RTS