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
66
67
68
69
70
71
72
73
|
/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
Changed by Andreas Schwab for long double
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <fp.h>
#include <math.h>
#ifdef __GNUC__
long double
DEFUN(atan2l, (y, x), long double y AND long double x)
{
long double one = 1.0, zero = 0.0;
long double signx, signy;
long double pi, PIo4, PIo2;
if (__isnanl(x))
return x;
if (__isnanl(y))
return y;
signy = __copysignl(one, y);
signx = __copysignl(one, x);
asm("fmovecr%.x %1, %0" : "=f" (pi) : "i" (0));
PIo2 = pi / 2;
PIo4 = pi / 4;
if (y == zero)
return signx == one ? y : __copysignl(pi, signy);
if (x == zero)
return __copysignl(PIo2, signy);
if (__isinfl(x))
{
if (__isinfl(y))
return __copysignl(signx == one ? PIo4 : 3 * PIo4, signy);
else
return __copysignl(signx == one ? zero : pi, signy);
}
if (__isinfl(y))
return __copysignl(PIo2, signy);
y = fabsl(y);
if (x < 0.0)
/* X is negative. */
return __copysignl(pi - atanl(y / -x), signy);
return __copysignl(atanl(y / x), signy);
}
#else
#include <sysdeps/generic/atan2l.c>
#endif
|
