ref: 85d0f0e1a2c05afee5a101c1e51a3ddd2ff2a5f6 dir: /sys/src/libc/386/387/sin.s/
TEXT sin(SB), $0 FMOVD a+0(FP), F0 FSIN RET TEXT cos(SB), $0 FMOVD a+0(FP), F0 FCOS RET