ref: 056eb9f7d8b1a577f7029e3d0e6d40cf6c2e86b0 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