ref: 854a1ab54f9af970059b167f2052598737c4ce31
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