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