/* * Written by J.T. Conklin <jtc@netbsd.org>. * Public domain. * * Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>. */ .file "log.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 _log .def _log; .scl 2; .type 32; .endef _log: fldln2 /* log(2) */ fldl 4(%esp) /* x : log(2) */ fld %st /* x : x : log(2) */ fsubl one /* x-1 : x : log(2) */ fld %st /* x-1 : x-1 : x : log(2) */ fabs /* |x-1| : x-1 : x : log(2) */ fcompl limit /* x-1 : x : log(2) */ fnstsw /* x-1 : x : log(2) */ andb $0x45, %ah jz 2f fstp %st(1) /* x-1 : log(2) */ fyl2xp1 /* log(x) */ ret 2: fstp %st(0) /* x : log(2) */ fyl2x /* log(x) */ ret