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 __lrintl = lrintl
32
33 #include <sys/isa_defs.h> /* _ILP32 */
34 #include "libm.h"
35
36 #if defined(_ILP32)
37 #if defined(__sparc)
38 #include "fma.h"
39 #include "fenv_inlines.h"
40
41 long
42 lrintl(long double x)
43 {
44 union {
45 unsigned int i[4];
46 long double q;
47 } xx;
48 union {
49 unsigned int i;
50 float f;
51 } tt;
52
53 unsigned int hx, sx, frac, l, fsr;
54 int rm, j;
55 volatile float dummy;
56
57 xx.q = x;
58 sx = xx.i[0] & 0x80000000;
59 hx = xx.i[0] & ~0x80000000;
60
61 /* handle trivial cases */
62 if (hx > 0x401e0000) { /* |x| > 2^31 + ... or x is nan */
63 /* convert an out-of-range float */
64 tt.i = sx | 0x7f000000;
65 return ((long)tt.f);
66 } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) { /* x is zero */
67 return (0L);
68 }
69
70 /* get the rounding mode */
71 __fenv_getfsr32(&fsr);
72 rm = fsr >> 30;
73
74 /* flip the sense of directed roundings if x is negative */
75 if (sx)
76 rm ^= rm >> 1;
77
78 /* handle |x| < 1 */
79 if (hx < 0x3fff0000) {
80 dummy = 1.0e30F; /* x is nonzero, so raise inexact */
81 dummy += 1.0e-30F;
82
83 if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 && ((hx &
84 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
85 return (sx ? -1L : 1L);
86
87 return (0L);
88 }
89
90 /* extract the integer and fractional parts of x */
91 j = 0x406f - (hx >> 16); /* 91 <= j <= 112 */
92 xx.i[0] = 0x10000 | (xx.i[0] & 0xffff);
93
94 if (j >= 96) { /* 96 <= j <= 112 */
95 l = xx.i[0] >> (j - 96);
96 frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
97
98 if (((xx.i[1] << 1) << (127 - j)) | xx.i[2] | xx.i[3])
99 frac |= 1;
100 } else { /* 91 <= j <= 95 */
101 l = (xx.i[0] << (96 - j)) | (xx.i[1] >> (j - 64));
102 frac = (xx.i[1] << (96 - j)) | (xx.i[2] >> (j - 64));
103
104 if ((xx.i[2] << (96 - j)) | xx.i[3])
105 frac |= 1;
106 }
107
108 /* round */
109 if (frac && (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000U ||
110 (frac == 0x80000000 && (l & 1))))))
111 l++;
112
113 /* check for result out of range (note that z is |x| at this point) */
114 if (l > 0x80000000U || (l == 0x80000000U && !sx)) {
115 tt.i = sx | 0x7f000000;
116 return ((long)tt.f);
117 }
118
119 /* raise inexact if need be */
120 if (frac) {
121 dummy = 1.0e30F;
122 dummy += 1.0e-30F;
123 }
124
125 /* negate result if need be */
126 if (sx)
127 l = -l;
128
129 return ((long)l);
130 }
131 #elif defined(__x86)
132 long
133 lrintl(long double x)
134 {
135 /*
136 * Note: The following code works on x86 (in the default rounding
137 * precision mode), but one ought to just use the fistpl instruction
138 * instead.
139 */
140 union {
141 unsigned i[3];
142 long double e;
143 } xx, yy;
144
145 int ex;
146
147 xx.e = x;
148 ex = xx.i[2] & 0x7fff;
149
150 if (ex < 0x403e) { /* |x| < 2^63 */
151 /* add and subtract a power of two to round x to an integer */
152 yy.i[2] = (xx.i[2] & 0x8000) | 0x403e;
153 yy.i[1] = 0x80000000;
154 yy.i[0] = 0;
155 x = (x + yy.e) - yy.e;
156 }
157
158 /* now x is nan, inf, or integral */
159 return ((long)x);
160 }
161 #else
162 #error Unknown architecture
163 #endif /* defined(__sparc) || defined(__x86) */
164 #else
165 #error Unsupported architecture
166 #endif /* defined(_ILP32) */