ref: 69e8a814d3e43f4c74059c60fb00ebc81857c8c5
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