summaryrefslogtreecommitdiff
path: root/lib/libm/noieee_src/n_floor.c
blob: 73debb3863ebc85fea7a502005b8e598ff1d0905 (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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/*      $NetBSD: n_floor.c,v 1.8 2014/03/16 09:51:39 martin Exp $ */
/*
 * Copyright (c) 1985, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
#if 0
static char sccsid[] = "@(#)floor.c	8.1 (Berkeley) 6/4/93";
#endif
#endif /* not lint */

#define _LIBM_STATIC
#include "mathimpl.h"

vc(L, 4503599627370496.0E0 ,0000,5c00,0000,0000, 55, 1.0) /* 2**55 */

ic(L, 4503599627370496.0E0, 52, 1.0)			  /* 2**52 */

#ifdef vccast
#define	L	vccast(L)
#endif

#ifdef __weak_alias
__weak_alias(ceill, ceil);
__weak_alias(floorl, floor);
__weak_alias(truncl, trunc);
#endif

/*
 * floor(x) := the largest integer no larger than x;
 * ceil(x) := -floor(-x), for all real x.
 *
 * Note: Inexact will be signaled if x is not an integer, as is
 *	customary for IEEE 754.  No other signal can be emitted.
 */
double
floor(double x)
{
	volatile double y;

	if (
#if !defined(__vax__)&&!defined(tahoe)
		x != x ||	/* NaN */
#endif	/* !defined(__vax__)&&!defined(tahoe) */
		x >= L)		/* already an even integer */
		return x;
	else if (x < (double)0)
		return -ceil(-x);
	else {			/* now 0 <= x < L */
		y = L+x;		/* destructive store must be forced */
		y -= L;			/* an integer, and |x-y| < 1 */
		return x < y ? y-(double)1 : y;
	}
}

float
floorf(float x)
{
	return floor((double)x);
}

double
ceil(double x)
{
	volatile double y;

	if (
#if !defined(__vax__)&&!defined(tahoe)
		x != x ||	/* NaN */
#endif	/* !defined(__vax__)&&!defined(tahoe) */
		x >= L)		/* already an even integer */
		return x;
	else if (x < (double)0)
		return -floor(-x);
	else {			/* now 0 <= x < L */
		y = L+x;		/* destructive store must be forced */
		y -= L;			/* an integer, and |x-y| < 1 */
		return x > y ? y+(double)1 : y;
	}
}

float
ceilf(float x)
{
	return ceil((double)x);
}

#ifndef ns32000			/* rint() is in ./NATIONAL/support.s */
/*
 * algorithm for rint(x) in pseudo-pascal form ...
 *
 * real rint(x): real x;
 *	... delivers integer nearest x in direction of prevailing rounding
 *	... mode
 * const	L = (last consecutive integer)/2
 * 	  = 2**55; for VAX D
 * 	  = 2**52; for IEEE 754 Double
 * real	s,t;
 * begin
 * 	if x != x then return x;		... NaN
 * 	if |x| >= L then return x;		... already an integer
 * 	s := copysign(L,x);
 * 	t := x + s;				... = (x+s) rounded to integer
 * 	return t - s
 * end;
 *
 * Note: Inexact will be signaled if x is not an integer, as is
 *	customary for IEEE 754.  No other signal can be emitted.
 */
double
rint(double x)
{
	double s;
	volatile double t;
	const double one = 1.0;

#if !defined(__vax__)&&!defined(tahoe)
	if (x != x)				/* NaN */
		return (x);
#endif	/* !defined(__vax__)&&!defined(tahoe) */
	if (copysign(x,one) >= L)		/* already an integer */
	    return (x);
	s = copysign(L,x);
	t = x + s;				/* x+s rounded to integer */
	return (t - s);
}
#endif	/* not national */

long
lrint(double x)
{
	double s;
	volatile double t;
	const double one = 1.0;

#if !defined(__vax__)&&!defined(tahoe)
	if (x != x)				/* NaN */
		return (x);
#endif	/* !defined(__vax__)&&!defined(tahoe) */
	if (copysign(x,one) >= L)		/* already an integer */
	    return (x);
	s = copysign(L,x);
	t = x + s;				/* x+s rounded to integer */
	return (t - s);
}

long long
llrint(double x)
{
	double s;
	volatile double t;
	const double one = 1.0;

#if !defined(__vax__)&&!defined(tahoe)
	if (x != x)				/* NaN */
		return (x);
#endif	/* !defined(__vax__)&&!defined(tahoe) */
	if (copysign(x,one) >= L)		/* already an integer */
	    return (x);
	s = copysign(L,x);
	t = x + s;				/* x+s rounded to integer */
	return (t - s);
}

long
lrintf(float x)
{
	float s;
	volatile float t;
	const float one = 1.0;

#if !defined(__vax__)&&!defined(tahoe)
	if (x != x)				/* NaN */
		return (x);
#endif	/* !defined(__vax__)&&!defined(tahoe) */
	if (copysign(x,one) >= L)		/* already an integer */
	    return (x);
	s = copysign(L,x);
	t = x + s;				/* x+s rounded to integer */
	return (t - s);
}

long long
llrintf(float x)
{
	float s;
	volatile float t;
	const float one = 1.0;

#if !defined(__vax__)&&!defined(tahoe)
	if (x != x)				/* NaN */
		return (x);
#endif	/* !defined(__vax__)&&!defined(tahoe) */
	if (copysign(x,one) >= L)		/* already an integer */
	    return (x);
	s = copysign(L,x);
	t = x + s;				/* x+s rounded to integer */
	return (t - s);
}

double
trunc(double x)
{
	return x < 0 ? ceil(x) : floor(x);
}

float
truncf(float x)
{
	return x < 0 ? ceilf(x) : floorf(x);
}