ref: 2d1dac07f7770e096d76ecbddea364ed538f0e70 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