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