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