blob: 392a10ff3555fbb7cbddd07329a67341fc3983cd (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
; $Id: logl.asm $
;; @file
; IPRT - No-CRT logl - AMD64 & X86.
;
;
; Copyright (C) 2006-2020 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)
|
