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
|
/* e_remainderl.c -- long double version of e_remainder.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, drepper@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/* __ieee754_remainderl(x,p)
* Return :
* returns x REM p = x - [x/p]*p as if in infinite
* precise arithmetic, where [x/p] is the (infinite bit)
* integer nearest x/p (in half way case choose the even one).
* Method :
* Based on fmod() return x-[x/p]chopped*p exactlp.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double zero = 0.0;
#else
static long double zero = 0.0;
#endif
#ifdef __STDC__
long double __ieee754_remainderl(long double x, long double p)
#else
long double __ieee754_remainderl(x,p)
long double x,p;
#endif
{
u_int32_t sx,sex,sep,x0,x1,p0,p1;
long double p_half;
GET_LDOUBLE_WORDS(sex,x0,x1,x);
GET_LDOUBLE_WORDS(sep,p0,p1,p);
sx = sex&0x8000;
sep &= 0x7fff;
sex &= 0x7fff;
/* purge off exception values */
if((sep|p0|p1)==0) return (x*p)/(x*p); /* p = 0 */
if((sex==0x7fff)|| /* x not finite */
((sep==0x7fff)&& /* p is NaN */
((p0|p1)!=0)))
return (x*p)/(x*p);
if (sep<0x7ffe) x = __ieee754_fmodl(x,p+p); /* now x < 2p */
if (((sex-sep)|(x0-p0)|(x1-p1))==0) return zero*x;
x = fabsl(x);
p = fabsl(p);
if (sep<0x0002) {
if(x+x>p) {
x-=p;
if(x+x>=p) x -= p;
}
} else {
p_half = 0.5*p;
if(x>p_half) {
x-=p;
if(x>=p_half) x -= p;
}
}
GET_LDOUBLE_EXP(sex,x);
SET_LDOUBLE_EXP(x,sex^sx);
return x;
}
|
