ref: c8600d1f7e7ba50027ff3b5d62c7511efecfb7f0 dir: /sys/src/libc/arm/tas.s/
TEXT _tas(SB), $-4 MOVW R0,R1 MOVW $1,R0 SWPW R0,(R1) /* fix: deprecated in armv7 */ RET