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5262 libm needs to be carefully unifdef'd
5268 libm doesn't need to hide symbols which are already local
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--- old/usr/src/lib/libm/common/C/scalbn.c
+++ new/usr/src/lib/libm/common/C/scalbn.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 23 */
24 24 /*
25 25 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
26 26 * Use is subject to license terms.
27 27 */
28 28
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29 29 #pragma weak scalbn = __scalbn
30 30
31 31 #include "libm.h"
32 32
33 33 static const double
34 34 one = 1.0,
35 35 huge = 1.0e300,
36 36 tiny = 1.0e-300,
37 37 twom54 = 5.5511151231257827021181583404541015625e-17;
38 38
39 -#if defined(USE_FPSCALE) || defined(__x86)
39 +#if defined(__x86)
40 40 static const double two52 = 4503599627370496.0;
41 41 #else
42 42 /*
43 43 * Normalize non-zero subnormal x and return biased exponent of x in [-51,0]
44 44 */
45 45 static int
46 46 ilogb_biased(unsigned *px) {
47 47 int s = 52;
48 48 unsigned v = px[HIWORD] & ~0x80000000, w = px[LOWORD], t = v;
49 49
50 50 if (t)
51 51 s -= 32;
52 52 else
53 53 t = w;
54 54 if (t & 0xffff0000)
55 55 s -= 16, t >>= 16;
56 56 if (t & 0xff00)
57 57 s -= 8, t >>= 8;
58 58 if (t & 0xf0)
59 59 s -= 4, t >>= 4;
60 60 t <<= 1;
61 61 s -= (0xffffaa50 >> t) & 0x3;
62 62 if (s < 32) {
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63 63 v = (v << s) | w >> (32 - s);
64 64 w <<= s;
65 65 } else {
66 66 v = w << (s - 32);
67 67 w = 0;
68 68 }
69 69 px[HIWORD] = (px[HIWORD] & 0x80000000) | v;
70 70 px[LOWORD] = w;
71 71 return (1 - s);
72 72 }
73 -#endif /* defined(USE_FPSCALE) */
73 +#endif /* defined(__x86) */
74 74
75 75 double
76 76 scalbn(double x, int n) {
77 77 int *px, ix, hx, k;
78 78
79 79 px = (int *)&x;
80 80 ix = px[HIWORD];
81 81 hx = ix & ~0x80000000;
82 82 k = hx >> 20;
83 83
84 84 if (k == 0x7ff) /* x is inf or NaN */
85 85 return (x * one);
86 86
87 87 if (k == 0) {
88 88 if ((hx | px[LOWORD]) == 0 || n == 0)
89 89 return (x);
90 -#if defined(USE_FPSCALE) || defined(__x86)
90 +#if defined(__x86)
91 91 x *= two52;
92 92 ix = px[HIWORD];
93 93 k = ((ix & ~0x80000000) >> 20) - 52;
94 94 #else
95 95 k = ilogb_biased((unsigned *)px);
96 96 ix = px[HIWORD];
97 97 #endif
98 98 /* now k is in the range -51..0 */
99 99 k += n;
100 100 if (k > n) /* integer overflow occurred */
101 101 k = -100;
102 102 } else {
103 103 /* k is in the range 1..1023 */
104 104 k += n;
105 105 if (k < n) /* integer overflow occurred */
106 106 k = 0x7ff;
107 107 }
108 108
109 109 if (k > 0x7fe)
110 110 return (huge * ((ix < 0)? -huge : huge));
111 111 if (k < 1) {
112 112 if (k <= -54)
113 113 return (tiny * ((ix < 0)? -tiny : tiny));
114 114 k += 54;
115 115 px[HIWORD] = (ix & ~0x7ff00000) | (k << 20);
116 116 return (x * twom54);
117 117 }
118 118 px[HIWORD] = (ix & ~0x7ff00000) | (k << 20);
119 119 return (x);
120 120 }
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