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Diffstat (limited to 'src/VBox/Runtime/common/math/log.asm')
| -rw-r--r-- | src/VBox/Runtime/common/math/log.asm | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/VBox/Runtime/common/math/log.asm b/src/VBox/Runtime/common/math/log.asm new file mode 100644 index 00000000..b94f3ba6 --- /dev/null +++ b/src/VBox/Runtime/common/math/log.asm @@ -0,0 +1,97 @@ +; $Id: log.asm $ +;; @file +; IPRT - No-CRT log - AMD64 & X86. +; + +; +; Copyright (C) 2006-2023 Oracle and/or its affiliates. +; +; This file is part of VirtualBox base platform packages, as +; available from https://www.virtualbox.org. +; +; This program is free software; you can redistribute it and/or +; modify it under the terms of the GNU General Public License +; as published by the Free Software Foundation, in version 3 of the +; License. +; +; This program is distributed in the hope that it will be useful, but +; WITHOUT ANY WARRANTY; without even the implied warranty of +; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +; General Public License for more details. +; +; You should have received a copy of the GNU General Public License +; along with this program; if not, see <https://www.gnu.org/licenses>. +; +; The contents of this file may alternatively be used under the terms +; of the Common Development and Distribution License Version 1.0 +; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included +; in the VirtualBox 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. +; +; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0 +; + + +%define RT_ASM_WITH_SEH64 +%include "iprt/asmdefs.mac" +%include "iprt/x86.mac" + + +BEGINCODE + +;; +; compute the natural logarithm of rd +; @returns st(0) / xmm0 +; @param rd [rbp + xCB*2] / xmm0 +RT_NOCRT_BEGINPROC log + push xBP + SEH64_PUSH_xBP + mov xBP, xSP + SEH64_SET_FRAME_xBP 0 +%ifdef RT_ARCH_AMD64 + sub xSP, 10h + SEH64_ALLOCATE_STACK 10h +%endif + SEH64_END_PROLOGUE + + fldln2 ; st0=log(2) +%ifdef RT_ARCH_AMD64 + movsd [xBP - 10h], xmm0 + fld qword [xBP - 10h] +%else + fld qword [xBP + xCB*2] ; st1=log(2) st0=lrd +%endif + 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, X86_FSW_C3 | X86_FSW_C2 | X86_FSW_C0 + 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: +%ifdef RT_ARCH_AMD64 + fstp qword [xBP - 10h] + movsd xmm0, [xBP - 10h] +%endif + leave + ret + +ALIGNCODE(8) +.one: dq 1.0 +.limit: dq 0.29 +ENDPROC RT_NOCRT(log) + |