ref: 2e94406e7f66b0c5f4e2b1d5c2158a37e8677724 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