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
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak __remainder = remainder
/*
* remainder(x,p)
* Code originated from 4.3bsd.
* Modified by K.C. Ng for SUN 4.0 libm.
* Return :
* returns x REM p = x - [x/p]*p as if in infinite precise arithmetic,
* where [x/p] is the (inifinite bit) integer nearest x/p (in half way
* case choose the even one).
* Method :
* Based on fmod() return x-[x/p]chopped*p exactly.
*/
#include "libm.h"
static const double zero = 0.0, half = 0.5;
double
remainder(double x, double p) {
double halfp;
int ix, hx, hp;
ix = ((int *)&x)[HIWORD];
hx = ix & ~0x80000000;
hp = ((int *)&p)[HIWORD] & ~0x80000000;
if (hp > 0x7ff00000 || (hp == 0x7ff00000 && ((int *)&p)[LOWORD] != 0))
return (x * p);
if (hx > 0x7ff00000 || (hx == 0x7ff00000 && ((int *)&x)[LOWORD] != 0))
return (x * p);
if ((hp | ((int *)&p)[LOWORD]) == 0 || hx == 0x7ff00000)
return (_SVID_libm_err(x, p, 28));
p = fabs(p);
if (hp < 0x7fe00000)
x = fmod(x, p + p);
x = fabs(x);
if (hp < 0x00200000) {
if (x + x > p) {
if (x == p) /* avoid x-x=-0 in RM mode */
return ((ix < 0)? -zero : zero);
x -= p;
if (x + x >= p)
x -= p;
}
} else {
halfp = half * p;
if (x > halfp) {
if (x == p) /* avoid x-x=-0 in RM mode */
return ((ix < 0)? -zero : zero);
x -= p;
if (x >= halfp)
x -= p;
}
}
return ((ix < 0)? -x : x);
}
|
