ref: 9482ba3dc7b2fc07e07b7ba08b7a07ffc8eca3c3 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