ref: 201c4b566f54ee0e5cb5122f9a9bf1a68b3466e2
dir: /sys/src/libc/386/387/log.s/
TEXT log(SB), $0 FMOVD $0.69314718055994530941, F0 FMOVD a+0(FP), F0 FTST WAIT FSTSW AX SAHF JLO bad FYL2X RET TEXT log10(SB), $0 FMOVD $0.30102999566398119521, F0 FMOVD a+0(FP), F0 FTST WAIT FSTSW AX SAHF JLO bad FYL2X RET bad: FMOVDP F0, F0 FMOVDP F0, F0 CALL NaN(SB) RET