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5261 libm should stop using synonyms.h
5298 fabs is 0-sized, confuses dis(1) and others
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Gordon Ross <gwr@nexenta.com>
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--- old/usr/src/lib/libm/common/Q/expl.c
+++ new/usr/src/lib/libm/common/Q/expl.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 /*
23 23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 24 */
25 25 /*
26 26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 27 * Use is subject to license terms.
28 28 */
29 29
30 30 /*
31 31 * expl(x)
32 32 * Table driven method
33 33 * Written by K.C. Ng, November 1988.
34 34 * Algorithm :
35 35 * 1. Argument Reduction: given the input x, find r and integer k
36 36 * and j such that
37 37 * x = (32k+j)*ln2 + r, |r| <= (1/64)*ln2 .
38 38 *
39 39 * 2. expl(x) = 2^k * (2^(j/32) + 2^(j/32)*expm1(r))
40 40 * Note:
41 41 * a. expm1(r) = (2r)/(2-R), R = r - r^2*(t1 + t2*r^2)
42 42 * b. 2^(j/32) is represented as
43 43 * _TBL_expl_hi[j]+_TBL_expl_lo[j]
44 44 * where
45 45 * _TBL_expl_hi[j] = 2^(j/32) rounded
46 46 * _TBL_expl_lo[j] = 2^(j/32) - _TBL_expl_hi[j].
47 47 *
48 48 * Special cases:
49 49 * expl(INF) is INF, expl(NaN) is NaN;
50 50 * expl(-INF)= 0;
51 51 * for finite argument, only expl(0)=1 is exact.
52 52 *
53 53 * Accuracy:
54 54 * according to an error analysis, the error is always less than
55 55 * an ulp (unit in the last place).
56 56 *
57 57 * Misc. info.
58 58 * For 113 bit long double
59 59 * if x > 1.135652340629414394949193107797076342845e+4
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60 60 * then expl(x) overflow;
61 61 * if x < -1.143346274333629787883724384345262150341e+4
62 62 * then expl(x) underflow
63 63 *
64 64 * Constants:
65 65 * Only decimal values are given. We assume that the compiler will convert
66 66 * from decimal to binary accurately enough to produce the correct
67 67 * hexadecimal values.
68 68 */
69 69
70 -#pragma weak expl = __expl
70 +#pragma weak __expl = expl
71 71
72 72 #include "libm.h"
73 73
74 74 extern const long double _TBL_expl_hi[], _TBL_expl_lo[];
75 75
76 76 static const long double
77 77 one = 1.0L,
78 78 two = 2.0L,
79 79 ln2_64 = 1.083042469624914545964425189778400898568e-2L,
80 80 ovflthreshold = 1.135652340629414394949193107797076342845e+4L,
81 81 unflthreshold = -1.143346274333629787883724384345262150341e+4L,
82 82 invln2_32 = 4.616624130844682903551758979206054839765e+1L,
83 83 ln2_32hi = 2.166084939249829091928849858592451515688e-2L,
84 84 ln2_32lo = 5.209643502595475652782654157501186731779e-27L;
85 85
86 86 /* rational approximation coeffs for [-(ln2)/64,(ln2)/64] */
87 87 static const long double
88 88 t1 = 1.666666666666666666666666666660876387437e-1L,
89 89 t2 = -2.777777777777777777777707812093173478756e-3L,
90 90 t3 = 6.613756613756613482074280932874221202424e-5L,
91 91 t4 = -1.653439153392139954169609822742235851120e-6L,
92 92 t5 = 4.175314851769539751387852116610973796053e-8L;
93 93
94 94 long double
95 95 expl(long double x) {
96 96 int *px = (int *) &x, ix, j, k, m;
97 97 long double t, r;
98 98
99 99 ix = px[0]; /* high word of x */
100 100 if (ix >= 0x7fff0000)
101 101 return (x + x); /* NaN of +inf */
102 102 if (((unsigned) ix) >= 0xffff0000)
103 103 return (-one / x); /* NaN or -inf */
104 104 if ((ix & 0x7fffffff) < 0x3fc30000) {
105 105 if ((int) x < 1)
106 106 return (one + x); /* |x|<2^-60 */
107 107 }
108 108 if (ix > 0) {
109 109 if (x > ovflthreshold)
110 110 return (scalbnl(x, 20000));
111 111 k = (int) (invln2_32 * (x + ln2_64));
112 112 } else {
113 113 if (x < unflthreshold)
114 114 return (scalbnl(-x, -40000));
115 115 k = (int) (invln2_32 * (x - ln2_64));
116 116 }
117 117 j = k&0x1f;
118 118 m = k>>5;
119 119 t = (long double) k;
120 120 x = (x - t * ln2_32hi) - t * ln2_32lo;
121 121 t = x * x;
122 122 r = (x - t * (t1 + t * (t2 + t * (t3 + t * (t4 + t * t5))))) - two;
123 123 x = _TBL_expl_hi[j] - ((_TBL_expl_hi[j] * (x + x)) / r -
124 124 _TBL_expl_lo[j]);
125 125 return (scalbnl(x, m));
126 126 }
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