1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 */
25
26 /*
27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 #pragma weak __rintf = rintf
32
33
34 /*
35 * aintf(x) return x chopped to integral value
36 * anintf(x) return sign(x)*(|x|+0.5) chopped to integral value
37 * irintf(x) return rint(x) in integer format
38 * nintf(x) return anint(x) in integer format
39 * rintf(x) return x rounded to integral according to the rounding direction
40 *
41 * NOTE: rintf(x), aintf(x) and anintf(x) return results with the same sign as
42 * x's, including 0.0.
43 */
44
45 #include "libm.h"
46
47 static const float xf[] = {
48 /* ZEROF */
49 0.0f,
50 /* TWO_23F */ 8.3886080000e6f,
51 /* MTWO_23F */ -8.3886080000e6f,
52 /* ONEF */ 1.0f,
53 /* MONEF */ -1.0f,
54 /* HALFF */ 0.5f,
55 /* MHALFF */ -0.5f,
56 /* HUGEF */ 1.0e30f,
57 };
58
59 #define ZEROF xf[0]
60 #define TWO_23F xf[1]
61 #define MTWO_23F xf[2]
62 #define ONEF xf[3]
63 #define MONEF xf[4]
64 #define HALFF xf[5]
65 #define MHALFF xf[6]
66 #define HUGEF xf[7]
67
68 float
69 aintf(float x)
70 {
71 int hx, k;
72 float y;
73
74 hx = *(int *)&x;
75 k = (hx & ~0x80000000) >> 23;
76
77 if (k < 150) {
78 y = (float)((int)x);
79
80 /*
81 * make sure y has the same sign of x when |x|<0.5
82 * (i.e., y=0.0)
83 */
84 return (((k - 127) & hx) < 0 ? -y : y);
85 } else {
86 /* signal invalid if x is a SNaN */
87 return (x * ONEF); /* +0 -> *1 for Cheetah */
88 }
89 }
90
91 float
92 anintf(float x)
93 {
94 volatile float dummy __unused;
95 int hx, k, j, ix;
96
97 hx = *(int *)&x;
98 ix = hx & ~0x80000000;
99 k = ix >> 23;
100
101 if (((k - 127) ^ (k - 150)) < 0) {
102 j = 1 << (149 - k);
103 k = j + j - 1;
104
105 if ((k & hx) != 0)
106 dummy = HUGEF + x; /* raise inexact */
107
108 *(int *)&x = (hx + j) & ~k;
109 return (x);
110 } else if (k <= 126) {
111 dummy = HUGEF + x;
112 *(int *)&x = (0x3f800000 & ((125 - k) >> 31)) |
113 (0x80000000 & hx);
114 return (x);
115 } else {
116 /* signal invalid if x is a SNaN */
117 return (x * ONEF); /* +0 -> *1 for Cheetah */
118 }
119 }
120
121 int
122 irintf(float x)
123 {
124 float v;
125 int hx, k;
126
127 hx = *(int *)&x;
128 k = (hx & ~0x80000000) >> 23;
129 v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
130 return ((int)((float)(x + v) - v));
131 }
132
133 int
134 nintf(float x)
135 {
136 int hx, ix, k, j, m;
137 volatile float dummy __unused;
138
139 hx = *(int *)&x;
140 k = (hx & ~0x80000000) >> 23;
141
142 if (((k - 126) ^ (k - 150)) < 0) {
143 ix = (hx & 0x00ffffff) | 0x800000;
144 m = 149 - k;
145 j = 1 << m;
146
147 if ((ix & (j + j - 1)) != 0)
148 dummy = HUGEF + x;
149
150 hx = hx >> 31;
151 return ((((ix + j) >> (m + 1)) ^ hx) - hx);
152 } else {
153 return ((int)x);
154 }
155 }
156
157 float
158 rintf(float x)
159 {
160 float w, v;
161 int hx, k;
162
163 hx = *(int *)&x;
164 k = (hx & ~0x80000000) >> 23;
165 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
166 if (k >= 150)
167 return (x * ONEF);
168
169 v = xf[1 - (hx >> 31)];
170 #else
171 v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
172 #endif
173 w = (float)(x + v);
174
175 if (k < 127 && w == v)
176 return (ZEROF * x);
177 else
178 return (w - v);
179 }