ref: 35e1aa1bfa5f1bdb2002b724e636ffe1ddea9a09 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