ref: 1cff9ab4e8412d5c6b6a3cbca720fbc4bcccecd9 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