/* * Written by J.T. Conklin . * Public domain. * * Adapted for `long double' by Ulrich Drepper . * * Changed to use fyl2xp1 for values near 1, . * * Removed header file dependency for use in libmingwex.a by * Danny Smith */ .file "log10l.S" .text .align 4 one: .double 1.0 /* It is not important that this constant is precise. It is only a value which is known to be on the safe side for using the fyl2xp1 instruction. */ limit: .double 0.29 .text .align 4 .globl _log10l .def _log10l; .scl 2; .type 32; .endef _log10l: fldlg2 // log10(2) fldt 4(%esp) // x : log10(2) fxam fnstsw fld %st // x : x : log10(2) sahf jc 3f // in case x is NaN or ħInf 4: fsubl one // x-1 : x : log10(2) fld %st // x-1 : x-1 : x : log10(2) fabs // |x-1| : x-1 : x : log10(2) fcompl limit // x-1 : x : log10(2) fnstsw // x-1 : x : log10(2) andb $0x45, %ah jz 2f fstp %st(1) // x-1 : log10(2) fyl2xp1 // log10(x) ret 2: fstp %st(0) // x : log10(2) fyl2x // log10(x) ret 3: jp 4b // in case x is ħInf fstp %st(1) fstp %st(1) ret