ref: f0ea8a3f6019b4fe7d37f33b0a5a3a88fd1fcdc7 dir: /sys/src/libc/arm/tas.s/
TEXT _tas(SB), 1, $-4 MOVW R0,R1 MOVW $1,R0 SWPW R0,(R1) /* fix: deprecated in armv7 */ RET