1 /* $NetBSD: n_floor.c,v 1.8 2014/03/16 09:51:39 martin Exp $ */
2 /*
3 * Copyright (c) 1985, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #ifndef lint
32 #if 0
33 static char sccsid[] = "@(#)floor.c 8.1 (Berkeley) 6/4/93";
34 #endif
35 #endif /* not lint */
36
37 #define _LIBM_STATIC
38 #include "mathimpl.h"
39
40 vc(L, 4503599627370496.0E0 ,0000,5c00,0000,0000, 55, 1.0) /* 2**55 */
41
42 ic(L, 4503599627370496.0E0, 52, 1.0) /* 2**52 */
43
44 #ifdef vccast
45 #define L vccast(L)
46 #endif
47
48 #ifdef __weak_alias
49 __weak_alias(ceill, ceil);
50 __weak_alias(floorl, floor);
51 __weak_alias(truncl, trunc);
52 #endif
53
54 /*
55 * floor(x) := the largest integer no larger than x;
56 * ceil(x) := -floor(-x), for all real x.
57 *
58 * Note: Inexact will be signaled if x is not an integer, as is
59 * customary for IEEE 754. No other signal can be emitted.
60 */
61 double
floor(double x)62 floor(double x)
63 {
64 volatile double y;
65
66 if (
67 #if !defined(__vax__)&&!defined(tahoe)
68 x != x || /* NaN */
69 #endif /* !defined(__vax__)&&!defined(tahoe) */
70 x >= L) /* already an even integer */
71 return x;
72 else if (x < (double)0)
73 return -ceil(-x);
74 else { /* now 0 <= x < L */
75 y = L+x; /* destructive store must be forced */
76 y -= L; /* an integer, and |x-y| < 1 */
77 return x < y ? y-(double)1 : y;
78 }
79 }
80
81 float
floorf(float x)82 floorf(float x)
83 {
84 return floor((double)x);
85 }
86
87 double
ceil(double x)88 ceil(double x)
89 {
90 volatile double y;
91
92 if (
93 #if !defined(__vax__)&&!defined(tahoe)
94 x != x || /* NaN */
95 #endif /* !defined(__vax__)&&!defined(tahoe) */
96 x >= L) /* already an even integer */
97 return x;
98 else if (x < (double)0)
99 return -floor(-x);
100 else { /* now 0 <= x < L */
101 y = L+x; /* destructive store must be forced */
102 y -= L; /* an integer, and |x-y| < 1 */
103 return x > y ? y+(double)1 : y;
104 }
105 }
106
107 float
ceilf(float x)108 ceilf(float x)
109 {
110 return ceil((double)x);
111 }
112
113 #ifndef ns32000 /* rint() is in ./NATIONAL/support.s */
114 /*
115 * algorithm for rint(x) in pseudo-pascal form ...
116 *
117 * real rint(x): real x;
118 * ... delivers integer nearest x in direction of prevailing rounding
119 * ... mode
120 * const L = (last consecutive integer)/2
121 * = 2**55; for VAX D
122 * = 2**52; for IEEE 754 Double
123 * real s,t;
124 * begin
125 * if x != x then return x; ... NaN
126 * if |x| >= L then return x; ... already an integer
127 * s := copysign(L,x);
128 * t := x + s; ... = (x+s) rounded to integer
129 * return t - s
130 * end;
131 *
132 * Note: Inexact will be signaled if x is not an integer, as is
133 * customary for IEEE 754. No other signal can be emitted.
134 */
135 double
rint(double x)136 rint(double x)
137 {
138 double s;
139 volatile double t;
140 const double one = 1.0;
141
142 #if !defined(__vax__)&&!defined(tahoe)
143 if (x != x) /* NaN */
144 return (x);
145 #endif /* !defined(__vax__)&&!defined(tahoe) */
146 if (copysign(x,one) >= L) /* already an integer */
147 return (x);
148 s = copysign(L,x);
149 t = x + s; /* x+s rounded to integer */
150 return (t - s);
151 }
152 #endif /* not national */
153
154 long
lrint(double x)155 lrint(double x)
156 {
157 double s;
158 volatile double t;
159 const double one = 1.0;
160
161 #if !defined(__vax__)&&!defined(tahoe)
162 if (x != x) /* NaN */
163 return (x);
164 #endif /* !defined(__vax__)&&!defined(tahoe) */
165 if (copysign(x,one) >= L) /* already an integer */
166 return (x);
167 s = copysign(L,x);
168 t = x + s; /* x+s rounded to integer */
169 return (t - s);
170 }
171
172 long long
llrint(double x)173 llrint(double x)
174 {
175 double s;
176 volatile double t;
177 const double one = 1.0;
178
179 #if !defined(__vax__)&&!defined(tahoe)
180 if (x != x) /* NaN */
181 return (x);
182 #endif /* !defined(__vax__)&&!defined(tahoe) */
183 if (copysign(x,one) >= L) /* already an integer */
184 return (x);
185 s = copysign(L,x);
186 t = x + s; /* x+s rounded to integer */
187 return (t - s);
188 }
189
190 long
lrintf(float x)191 lrintf(float x)
192 {
193 float s;
194 volatile float t;
195 const float one = 1.0;
196
197 #if !defined(__vax__)&&!defined(tahoe)
198 if (x != x) /* NaN */
199 return (x);
200 #endif /* !defined(__vax__)&&!defined(tahoe) */
201 if (copysign(x,one) >= L) /* already an integer */
202 return (x);
203 s = copysign(L,x);
204 t = x + s; /* x+s rounded to integer */
205 return (t - s);
206 }
207
208 long long
llrintf(float x)209 llrintf(float x)
210 {
211 float s;
212 volatile float t;
213 const float one = 1.0;
214
215 #if !defined(__vax__)&&!defined(tahoe)
216 if (x != x) /* NaN */
217 return (x);
218 #endif /* !defined(__vax__)&&!defined(tahoe) */
219 if (copysign(x,one) >= L) /* already an integer */
220 return (x);
221 s = copysign(L,x);
222 t = x + s; /* x+s rounded to integer */
223 return (t - s);
224 }
225
226 double
trunc(double x)227 trunc(double x)
228 {
229 return x < 0 ? ceil(x) : floor(x);
230 }
231
232 float
truncf(float x)233 truncf(float x)
234 {
235 return x < 0 ? ceilf(x) : floorf(x);
236 }
237