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 __llrintl = llrintl
32 #if defined(__sparcv9) || defined(__amd64)
33 #pragma weak lrintl = llrintl
34 #pragma weak __lrintl = llrintl
35 #endif
36
37 #include "libm.h"
38
39 #if defined(__sparc)
40 #include "fma.h"
41 #include "fenv_inlines.h"
42
43 long long
44 llrintl(long double x)
45 {
46 union {
47 unsigned i[4];
48 long double q;
49 } xx;
50 union {
51 unsigned i[2];
52 long long l;
53 } zz;
54 union {
55 unsigned i;
56 float f;
57 } tt;
58
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
76 /* get the rounding mode */
77 __fenv_getfsr32(&fsr);
78 rm = fsr >> 30;
79
80 /* flip the sense of directed roundings if x is negative */
81 if (sx)
82 rm ^= rm >> 1;
83
84 /* handle |x| < 1 */
85 if (hx < 0x3fff0000) {
86 dummy = 1.0e30f; /* x is nonzero, so raise inexact */
87 dummy += 1.0e-30f;
88
89 if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 && ((hx &
90 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
91 return (sx ? -1LL : 1LL);
92
93 return (0LL);
94 }
95
96 /* extract the integer and fractional parts of x */
97 j = 0x406f - (hx >> 16);
98 xx.i[0] = 0x10000 | (xx.i[0] & 0xffff);
99
100 if (j >= 96) {
101 zz.i[0] = 0;
102 zz.i[1] = xx.i[0] >> (j - 96);
103 frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
104
105 if (((xx.i[1] << 1) << (127 - j)) | xx.i[2] | xx.i[3])
106 frac |= 1;
107 } else if (j >= 64) {
108 zz.i[0] = xx.i[0] >> (j - 64);
109 zz.i[1] = ((xx.i[0] << 1) << (95 - j)) | (xx.i[1] >> (j - 64));
110 frac = ((xx.i[1] << 1) << (95 - j)) | (xx.i[2] >> (j - 64));
111
112 if (((xx.i[2] << 1) << (95 - j)) | xx.i[3])
113 frac |= 1;
114 } else {
115 zz.i[0] = ((xx.i[0] << 1) << (63 - j)) | (xx.i[1] >> (j - 32));
116 zz.i[1] = ((xx.i[1] << 1) << (63 - j)) | (xx.i[2] >> (j - 32));
117 frac = ((xx.i[2] << 1) << (63 - j)) | (xx.i[3] >> (j - 32));
118
119 if ((xx.i[3] << 1) << (63 - j))
120 frac |= 1;
121 }
122
123 /* round */
124 if (frac && (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
125 (frac == 0x80000000 && (zz.i[1] & 1)))))) {
126 if (++zz.i[1] == 0)
127 zz.i[0]++;
128 }
129
130 /* check for result out of range (note that z is |x| at this point) */
131 if (zz.i[0] > 0x80000000u || (zz.i[0] == 0x80000000 && (zz.i[1] ||
132 !sx))) {
133 tt.i = sx | 0x7f000000;
134 return ((long long)tt.f);
135 }
136
137 /* raise inexact if need be */
138 if (frac) {
139 dummy = 1.0e30F;
140 dummy += 1.0e-30F;
141 }
142
143 /* negate result if need be */
144 if (sx) {
145 zz.i[0] = ~zz.i[0];
146 zz.i[1] = -zz.i[1];
147
148 if (zz.i[1] == 0)
149 zz.i[0]++;
150 }
151
152 return (zz.l);
153 }
154 #elif defined(__x86)
155 long long
156 llrintl(long double x)
157 {
158 /*
159 * Note: The following code works on x86 (in the default rounding
160 * precision mode), but one ought to just use the fistpll instruction
161 * instead.
162 */
163 union {
164 unsigned i[3];
165 long double e;
166 } xx, yy;
167
168 int ex;
169
170 xx.e = x;
171 ex = xx.i[2] & 0x7fff;
172
173 if (ex < 0x403e) { /* |x| < 2^63 */
174 /* add and subtract a power of two to round x to an integer */
175 yy.i[2] = (xx.i[2] & 0x8000) | 0x403e;
176 yy.i[1] = 0x80000000;
177 yy.i[0] = 0;
178 x = (x + yy.e) - yy.e;
179 }
180
181 /* now x is nan, inf, or integral */
182 return ((long long)x);
183 }
184 #else
185 #error Unknown architecture
186 #endif