ref: 6e6beff85d3f2d71c4e1d92d1f2091d01c7d5c34 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