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 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 * Use is subject to license terms.
28 */
29
30 #pragma weak __rintf = rintf
31
32 /* INDENT OFF */
33 /*
34 * aintf(x) return x chopped to integral value
35 * anintf(x) return sign(x)*(|x|+0.5) chopped to integral value
36 * irintf(x) return rint(x) in integer format
37 * nintf(x) return anint(x) in integer format
38 * rintf(x) return x rounded to integral according to the rounding direction
39 *
40 * NOTE: rintf(x), aintf(x) and anintf(x) return results with the same sign as
41 * x's, including 0.0.
42 */
43
44 #include "libm.h"
45
46 static const float xf[] = {
47 /* ZEROF */ 0.0f,
48 /* TWO_23F */ 8.3886080000e6f,
49 /* MTWO_23F */ -8.3886080000e6f,
50 /* ONEF */ 1.0f,
51 /* MONEF */ -1.0f,
52 /* HALFF */ 0.5f,
53 /* MHALFF */ -0.5f,
54 /* HUGEF */ 1.0e30f,
55 };
56
57 #define ZEROF xf[0]
58 #define TWO_23F xf[1]
59 #define MTWO_23F xf[2]
60 #define ONEF xf[3]
61 #define MONEF xf[4]
62 #define HALFF xf[5]
63 #define MHALFF xf[6]
64 #define HUGEF xf[7]
65 /* INDENT ON */
66
67 float
68 aintf(float x) {
69 int hx, k;
70 float y;
71
72 hx = *(int *) &x;
73 k = (hx & ~0x80000000) >> 23;
74 if (k < 150) {
75 y = (float) ((int) x);
76 /*
77 * make sure y has the same sign of x when |x|<0.5
78 * (i.e., y=0.0)
79 */
80 return (((k - 127) & hx) < 0 ? -y : y);
81 } else
82 /* signal invalid if x is a SNaN */
83 return (x * ONEF); /* +0 -> *1 for Cheetah */
84 }
85
86 float
87 anintf(float x) {
88 volatile float dummy __unused;
89 int hx, k, j, ix;
90
91 hx = *(int *) &x;
92 ix = hx & ~0x80000000;
93 k = ix >> 23;
94 if (((k - 127) ^ (k - 150)) < 0) {
95 j = 1 << (149 - k);
96 k = j + j - 1;
97 if ((k & hx) != 0)
98 dummy = HUGEF + x; /* raise inexact */
99 *(int *) &x = (hx + j) & ~k;
100 return (x);
101 } else if (k <= 126) {
102 dummy = HUGEF + x;
103 *(int *) &x = (0x3f800000 & ((125 - k) >> 31)) |
104 (0x80000000 & hx);
105 return (x);
106 } else
107 /* signal invalid if x is a SNaN */
108 return (x * ONEF); /* +0 -> *1 for Cheetah */
109 }
110
111 int
112 irintf(float x) {
113 float v;
114 int hx, k;
115
116 hx = *(int *) &x;
117 k = (hx & ~0x80000000) >> 23;
118 v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
119 return ((int) ((float) (x + v) - v));
120 }
121
122 int
123 nintf(float x) {
124 int hx, ix, k, j, m;
125 volatile float dummy __unused;
126
127 hx = *(int *) &x;
128 k = (hx & ~0x80000000) >> 23;
129 if (((k - 126) ^ (k - 150)) < 0) {
130 ix = (hx & 0x00ffffff) | 0x800000;
131 m = 149 - k;
132 j = 1 << m;
133 if ((ix & (j + j - 1)) != 0)
134 dummy = HUGEF + x;
135 hx = hx >> 31;
136 return ((((ix + j) >> (m + 1)) ^ hx) - hx);
137 } else
138 return ((int) x);
139 }
140
141 float
142 rintf(float x) {
143 float w, v;
144 int hx, k;
145
146 hx = *(int *) &x;
147 k = (hx & ~0x80000000) >> 23;
148 #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
149 if (k >= 150)
150 return (x * ONEF);
151 v = xf[1 - (hx >> 31)];
152 #else
153 v = xf[((k - 150) >> 31) & (1 - (hx >> 31))];
154 #endif
155 w = (float) (x + v);
156 if (k < 127 && w == v)
157 return (ZEROF * x);
158 else
159 return (w - v);
160 }