ref: 23f3d33cdbbfdf2f169f1d7c4acf1f947ed5f5c5 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