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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 #pragma weak sqrtf = __sqrtf
30
31 #include "libm.h"
32
33 #ifdef __INLINE
34
35 extern float __inline_sqrtf(float);
36
37 float
38 sqrtf(float x) {
39 return (__inline_sqrtf(x));
40 }
41
42 #else /* defined(__INLINE) */
43
44 static const float huge = 1.0e35F, tiny = 1.0e-35F, zero = 0.0f;
45
46 float
47 sqrtf(float x) {
48 float dz, w;
49 int *pw = (int *)&w;
50 int ix, j, r, q, m, n, s, t;
51
52 w = x;
53 ix = pw[0];
54 if (ix <= 0) {
55 /* x is <= 0 or nan */
56 j = ix & 0x7fffffff;
57 if (j == 0)
58 return (w);
59 return ((w * zero) / zero);
60 }
61
62 if ((ix & 0x7f800000) == 0x7f800000) {
63 /* x is +inf or nan */
64 return (w * w);
65 }
66
67 m = ir_ilogb_(&w);
68 n = -m;
69 w = r_scalbn_(&w, (int *)&n);
70 ix = (pw[0] & 0x007fffff) | 0x00800000;
71 n = m / 2;
72 if ((n + n) != m) {
73 ix = ix + ix;
74 m -= 1;
75 n = m / 2;
76 }
77
78 /* generate sqrt(x) bit by bit */
79 ix <<= 1;
80 q = s = 0;
81 r = 0x01000000;
82 for (j = 1; j <= 25; j++) {
83 t = s + r;
84 if (t <= ix) {
85 s = t + r;
86 ix -= t;
87 q += r;
88 }
89 ix <<= 1;
90 r >>= 1;
91 }
92 if (ix == 0)
93 goto done;
94
95 /* raise inexact and determine the ambient rounding mode */
96 dz = huge - tiny;
97 if (dz < huge)
98 goto done;
99 dz = huge + tiny;
100 if (dz > huge)
101 q += 1;
102 q += (q & 1);
103
104 done:
105 pw[0] = (q >> 1) + 0x3f000000;
106 return (r_scalbn_(&w, (int *)&n));
107 }
108
109 #endif /* defined(__INLINE) */
|
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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 #pragma weak __sqrtf = sqrtf
30
31 #include "libm.h"
32
33
34 extern float __inline_sqrtf(float);
35
36 float
37 sqrtf(float x) {
38 return (__inline_sqrtf(x));
39 }
40
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