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Diffstat (limited to 'src/VBox/Runtime/common/math/logl.asm')
| -rw-r--r-- | src/VBox/Runtime/common/math/logl.asm | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/logl.asm b/src/VBox/Runtime/common/math/logl.asm new file mode 100644 index 00000000..71dd91e6 --- /dev/null +++ b/src/VBox/Runtime/common/math/logl.asm @@ -0,0 +1,65 @@ +; $Id: logl.asm $ +;; @file +; IPRT - No-CRT logl - AMD64 & X86. +; + +; +; Copyright (C) 2006-2019 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] +BEGINPROC RT_NOCRT(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) + |