logl.asm revision 1c94c0a63ba68be1a7b2c640e70d7a06464e4fca
6035a3d1ce01a78c316578f23393c0b7edca0548vboxsync; $Id$
6035a3d1ce01a78c316578f23393c0b7edca0548vboxsync;; @file
64082f4699f276693cf5b1ec5886ac12234af115vboxsync; innotek Portable Runtime - No-CRT logl - AMD64 & X86.
64082f4699f276693cf5b1ec5886ac12234af115vboxsync;
6035a3d1ce01a78c316578f23393c0b7edca0548vboxsync
64082f4699f276693cf5b1ec5886ac12234af115vboxsync;
6035a3d1ce01a78c316578f23393c0b7edca0548vboxsync; Copyright (C) 2006-2007 Sun Microsystems, Inc.
64082f4699f276693cf5b1ec5886ac12234af115vboxsync;
6035a3d1ce01a78c316578f23393c0b7edca0548vboxsync; This file is part of VirtualBox Open Source Edition (OSE), as
; available from http://www.virtualbox.org. This file is free software;
; you can redistribute it and/or modify it under the terms of the GNU
; General Public License (GPL) as published by the Free Software
; Foundation, in version 2 as it comes in the "COPYING" file of the
; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
;
; The contents of this file may alternatively be used under the terms
; of the Common Development and Distribution License Version 1.0
; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
; VirtualBox OSE distribution, in which case the provisions of the
; CDDL are applicable instead of those of the GPL.
;
; You may elect to license modified versions of this file under the
; terms and conditions of either the GPL or the CDDL or both.
;
; Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
; Clara, CA 95054 USA or visit http://www.sun.com if you need
; additional information or have any questions.
;
%include "iprt/asmdefs.mac"
BEGINCODE
%ifdef RT_ARCH_AMD64
%define _SP rsp
%define _BP rbp
%define _S 8
%else
%define _SP esp
%define _BP ebp
%define _S 4
%endif
;;
; compute the natural logarithm of lrd
; @returns st(0)
; @param lrd [rbp + _S*2]
BEGINPROC RT_NOCRT(logl)
push _BP
mov _BP, _SP
sub _SP, 10h
fldln2 ; st0=log(2)
fld tword [_BP + _S*2] ; st1=log(2) st0=lrd
fld st0 ; st1=log(2) st0=lrd st0=lrd
fsub qword [.one] ; st2=log(2) st1=lrd st0=lrd-1.0
fld st0 ; st3=log(2) st2=lrd st1=lrd-1.0 st0=lrd-1.0
fabs ; st3=log(2) st2=lrd st1=lrd-1.0 st0=abs(lrd-1.0)
fcomp qword [.limit] ; st2=log(2) st1=lrd st0=lrd-1.0
fnstsw ax
and eax, 04500h
jnz .use_st1
fstp st0 ; st1=log(2) st0=lrd
fyl2x ; log(lrd)
jmp .done
.use_st1:
fstp st1 ; st1=log(2) st0=lrd-1.0
fyl2xp1 ; log(lrd)
.done:
leave
ret
.one: dq 1.0
.limit: dq 0.29
ENDPROC RT_NOCRT(logl)