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 nearbyintl = __nearbyintl
31
32 #include "libm.h"
33 #include "fma.h"
34 #include "fenv_inlines.h"
35
36 #if defined(__sparc)
37
38 static union {
39 unsigned i;
40 float f;
41 } snan = { 0x7f800001 };
42
43 long double
44 __nearbyintl(long double x) {
45 union {
46 unsigned i[4];
47 long double q;
48 } xx;
49 unsigned hx, sx, i, frac;
50 unsigned int fsr;
51 int rm, j;
52 volatile float dummy;
53
54 xx.q = x;
55 sx = xx.i[0] & 0x80000000;
56 hx = xx.i[0] & ~0x80000000;
57
58 /* handle trivial cases */
59 if (hx >= 0x406f0000) { /* x is nan, inf, or already integral */
60 /* check for signaling nan */
61 if ((hx > 0x7fff0000 || (hx == 0x7fff0000 &&
62 (xx.i[1] | xx.i[2] | xx.i[3]))) && !(hx & 0x8000)) {
63 dummy = snan.f;
64 dummy += snan.f;
65 xx.i[0] = sx | hx | 0x8000;
66 }
67 return (xx.q);
68 } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) /* x is zero */
69 return (x);
70
71 /* get the rounding mode */
72 __fenv_getfsr32(&fsr);
73 rm = fsr >> 30;
74
75 /* flip the sense of directed roundings if x is negative */
76 if (sx)
77 rm ^= rm >> 1;
78
79 /* handle |x| < 1 */
80 if (hx < 0x3fff0000) {
81 if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 &&
82 ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
83 xx.i[0] = sx | 0x3fff0000;
84 else
85 xx.i[0] = sx;
86 xx.i[1] = xx.i[2] = xx.i[3] = 0;
87 return (xx.q);
88 }
89
90 /* round x at the integer bit */
91 j = 0x406f - (hx >> 16);
92 if (j >= 96) {
93 i = 1 << (j - 96);
94 frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
95 if ((xx.i[1] & (i - 1)) | xx.i[2] | xx.i[3])
96 frac |= 1;
97 if (!frac)
98 return (x);
99 xx.i[1] = xx.i[2] = xx.i[3] = 0;
100 xx.i[0] &= ~(i - 1);
101 if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
102 (frac == 0x80000000 && (xx.i[0] & i)))))
103 xx.i[0] += i;
104 } else if (j >= 64) {
105 i = 1 << (j - 64);
106 frac = ((xx.i[1] << 1) << (95 - j)) | (xx.i[2] >> (j - 64));
107 if ((xx.i[2] & (i - 1)) | xx.i[3])
108 frac |= 1;
109 if (!frac)
110 return (x);
111 xx.i[2] = xx.i[3] = 0;
112 xx.i[1] &= ~(i - 1);
113 if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
114 (frac == 0x80000000 && (xx.i[1] & i))))) {
115 xx.i[1] += i;
116 if (xx.i[1] == 0)
117 xx.i[0]++;
118 }
119 } else if (j >= 32) {
120 i = 1 << (j - 32);
121 frac = ((xx.i[2] << 1) << (63 - j)) | (xx.i[3] >> (j - 32));
122 if (xx.i[3] & (i - 1))
123 frac |= 1;
124 if (!frac)
125 return (x);
126 xx.i[3] = 0;
127 xx.i[2] &= ~(i - 1);
128 if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
129 (frac == 0x80000000 && (xx.i[2] & i))))) {
130 xx.i[2] += i;
131 if (xx.i[2] == 0)
132 if (++xx.i[1] == 0)
133 xx.i[0]++;
134 }
135 } else {
136 i = 1 << j;
137 frac = (xx.i[3] << 1) << (31 - j);
138 if (!frac)
139 return (x);
140 xx.i[3] &= ~(i - 1);
141 if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
142 (frac == 0x80000000 && (xx.i[3] & i))))) {
143 xx.i[3] += i;
144 if (xx.i[3] == 0)
145 if (++xx.i[2] == 0)
146 if (++xx.i[1] == 0)
147 xx.i[0]++;
148 }
149 }
150
151 return (xx.q);
152 }
153
154 #elif defined(__x86)
155
156 /* inline template */
157 extern long double frndint(long double);
158
159 long double
160 __nearbyintl(long double x) {
161 long double z;
162 unsigned oldcwsw, cwsw;
163
164 /* save the control and status words, mask the inexact exception */
165 __fenv_getcwsw(&oldcwsw);
166 cwsw = oldcwsw | 0x00200000;
167 __fenv_setcwsw(&cwsw);
168
169 z = frndint(x);
170
171 /*
172 * restore the control and status words, preserving all but the
173 * inexact flag
174 */
175 __fenv_getcwsw(&cwsw);
176 oldcwsw |= (cwsw & 0x1f);
177 __fenv_setcwsw(&oldcwsw);
178
179 return (z);
180 }
181
182 #else
183 #error Unknown architecture
184 #endif