; $Id: logl.asm 96014 2022-08-04 01:48:12Z vboxsync $ ;; @file ; IPRT - No-CRT logl - AMD64 & X86. ; ; ; Copyright (C) 2006-2022 Oracle Corporation ; ; 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. ; %include "iprt/asmdefs.mac" BEGINCODE ;; ; compute the natural logarithm of lrd ; @returns st(0) ; @param lrd [rbp + xCB*2] RT_NOCRT_BEGINPROC logl push xBP mov xBP, xSP sub xSP, 10h fldln2 ; st0=log(2) fld tword [xBP + xCB*2] ; st1=log(2) st0=lrd fld st0 ; st1=log(2) st0=lrd st0=lrd fsub qword [.one xWrtRIP] ; 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 xWrtRIP] ; 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)