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 llrintl = __llrintl
32 #if defined(__sparcv9) || defined(__amd64)
33 #pragma weak lrintl = __llrintl
34 #pragma weak __lrintl = __llrintl
35 #endif
36 #endif
37
38 #include "libm.h"
39
40 #if defined(__sparc)
41
42 #include "fma.h"
43 #include "fenv_inlines.h"
44
45 long long
46 llrintl(long double x) {
47 union {
48 unsigned i[4];
49 long double q;
50 } xx;
51 union {
52 unsigned i[2];
53 long long l;
54 } zz;
55 union {
56 unsigned i;
57 float f;
58 } tt;
59 unsigned int hx, sx, frac, fsr;
60 int rm, j;
61 volatile float dummy;
62
63 xx.q = x;
64 sx = xx.i[0] & 0x80000000;
65 hx = xx.i[0] & ~0x80000000;
66
67 /* handle trivial cases */
68 if (hx > 0x403e0000) { /* |x| > 2^63 + ... or x is nan */
69 /* convert an out-of-range float */
70 tt.i = sx | 0x7f000000;
71 return ((long long) tt.f);
72 } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) /* x is zero */
73 return (0LL);
74
75 /* get the rounding mode */
76 __fenv_getfsr32(&fsr);
77 rm = fsr >> 30;
78
79 /* flip the sense of directed roundings if x is negative */
80 if (sx)
81 rm ^= rm >> 1;
82
83 /* handle |x| < 1 */
84 if (hx < 0x3fff0000) {
85 dummy = 1.0e30f; /* x is nonzero, so raise inexact */
86 dummy += 1.0e-30f;
87 if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 &&
88 ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
89 return (sx ? -1LL : 1LL);
90 return (0LL);
91 }
92
93 /* extract the integer and fractional parts of x */
94 j = 0x406f - (hx >> 16);
95 xx.i[0] = 0x10000 | (xx.i[0] & 0xffff);
96 if (j >= 96) {
97 zz.i[0] = 0;
98 zz.i[1] = xx.i[0] >> (j - 96);
99 frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
100 if (((xx.i[1] << 1) << (127 - j)) | xx.i[2] | xx.i[3])
101 frac |= 1;
102 } else if (j >= 64) {
103 zz.i[0] = xx.i[0] >> (j - 64);
104 zz.i[1] = ((xx.i[0] << 1) << (95 - j)) | (xx.i[1] >> (j - 64));
105 frac = ((xx.i[1] << 1) << (95 - j)) | (xx.i[2] >> (j - 64));
106 if (((xx.i[2] << 1) << (95 - j)) | xx.i[3])
107 frac |= 1;
108 } else {
109 zz.i[0] = ((xx.i[0] << 1) << (63 - j)) | (xx.i[1] >> (j - 32));
110 zz.i[1] = ((xx.i[1] << 1) << (63 - j)) | (xx.i[2] >> (j - 32));
111 frac = ((xx.i[2] << 1) << (63 - j)) | (xx.i[3] >> (j - 32));
112 if ((xx.i[3] << 1) << (63 - j))
113 frac |= 1;
114 }
115
116 /* round */
117 if (frac && (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
118 (frac == 0x80000000 && (zz.i[1] & 1)))))) {
119 if (++zz.i[1] == 0)
120 zz.i[0]++;
121 }
122
123 /* check for result out of range (note that z is |x| at this point) */
124 if (zz.i[0] > 0x80000000u || (zz.i[0] == 0x80000000 && (zz.i[1] ||
125 !sx))) {
126 tt.i = sx | 0x7f000000;
127 return ((long long) tt.f);
128 }
129
130 /* raise inexact if need be */
131 if (frac) {
132 dummy = 1.0e30F;
133 dummy += 1.0e-30F;
134 }
135
136 /* negate result if need be */
137 if (sx) {
138 zz.i[0] = ~zz.i[0];
139 zz.i[1] = -zz.i[1];
140 if (zz.i[1] == 0)
141 zz.i[0]++;
142 }
143 return (zz.l);
144 }
145 #elif defined(__x86)
146 long long
147 llrintl(long double x) {
148 /*
149 * Note: The following code works on x86 (in the default rounding
150 * precision mode), but one ought to just use the fistpll instruction
151 * instead.
152 */
153 union {
154 unsigned i[3];
155 long double e;
156 } xx, yy;
157 int ex;
158
159 xx.e = x;
160 ex = xx.i[2] & 0x7fff;
161
162 if (ex < 0x403e) { /* |x| < 2^63 */
163 /* add and subtract a power of two to round x to an integer */
164 yy.i[2] = (xx.i[2] & 0x8000) | 0x403e;
165 yy.i[1] = 0x80000000;
166 yy.i[0] = 0;
167 x = (x + yy.e) - yy.e;
168 }
169
170 /* now x is nan, inf, or integral */
171 return ((long long) x);
172 }
173 #else
174 #error Unknown architecture
175 #endif