VirtualBox

source: vbox/trunk/src/VBox/Runtime/common/math/logf.asm

Last change on this file was 98103, checked in by vboxsync, 16 months ago

Copyright year updates by scm.

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1; $Id: logf.asm 98103 2023-01-17 14:15:46Z vboxsync $
2;; @file
3; IPRT - No-CRT logf - AMD64 & X86.
4;
5
6;
7; Copyright (C) 2006-2023 Oracle and/or its affiliates.
8;
9; This file is part of VirtualBox base platform packages, as
10; available from https://www.virtualbox.org.
11;
12; This program is free software; you can redistribute it and/or
13; modify it under the terms of the GNU General Public License
14; as published by the Free Software Foundation, in version 3 of the
15; License.
16;
17; This program is distributed in the hope that it will be useful, but
18; WITHOUT ANY WARRANTY; without even the implied warranty of
19; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20; General Public License for more details.
21;
22; You should have received a copy of the GNU General Public License
23; along with this program; if not, see <https://www.gnu.org/licenses>.
24;
25; The contents of this file may alternatively be used under the terms
26; of the Common Development and Distribution License Version 1.0
27; (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28; in the VirtualBox distribution, in which case the provisions of the
29; CDDL are applicable instead of those of the GPL.
30;
31; You may elect to license modified versions of this file under the
32; terms and conditions of either the GPL or the CDDL or both.
33;
34; SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35;
36
37
38%define RT_ASM_WITH_SEH64
39%include "iprt/asmdefs.mac"
40%include "iprt/x86.mac"
41
42
43BEGINCODE
44
45;;
46; compute the natural logarithm of r32
47; @returns st(0) / xmm0
48; @param r32 [rbp + xCB*2] / xmm0
49RT_NOCRT_BEGINPROC logf
50 push xBP
51 SEH64_PUSH_xBP
52 mov xBP, xSP
53 SEH64_SET_FRAME_xBP 0
54%ifdef RT_ARCH_AMD64
55 sub xSP, 10h
56 SEH64_ALLOCATE_STACK 10h
57%endif
58 SEH64_END_PROLOGUE
59
60 fldln2 ; st0=log(2)
61%ifdef RT_ARCH_AMD64
62 movss [xBP - 10h], xmm0
63 fld dword [xBP - 10h]
64%else
65 fld dword [xBP + xCB*2] ; st1=log(2) st0=lrd
66%endif
67 fld st0 ; st1=log(2) st0=lrd st0=lrd
68 fsub qword [.one xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
69 fld st0 ; st3=log(2) st2=lrd st1=lrd-1.0 st0=lrd-1.0
70
71 fabs ; st3=log(2) st2=lrd st1=lrd-1.0 st0=abs(lrd-1.0)
72 fcomp qword [.limit xWrtRIP] ; st2=log(2) st1=lrd st0=lrd-1.0
73 fnstsw ax
74 and eax, X86_FSW_C3 | X86_FSW_C2 | X86_FSW_C0
75 jnz .use_st1
76
77 fstp st0 ; st1=log(2) st0=lrd
78 fyl2x ; log(lrd)
79 jmp .done
80
81.use_st1:
82 fstp st1 ; st1=log(2) st0=lrd-1.0
83 fyl2xp1 ; log(lrd)
84
85.done:
86%ifdef RT_ARCH_AMD64
87 fstp dword [xBP - 10h]
88 movss xmm0, [xBP - 10h]
89%endif
90 leave
91 ret
92
93ALIGNCODE(8)
94.one: dq 1.0
95.limit: dq 0.29
96ENDPROC RT_NOCRT(logf)
97
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