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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/hypotl.c
+++ new/usr/src/lib/libm/common/Q/hypotl.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
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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 -#pragma weak hypotl = __hypotl
30 +#pragma weak __hypotl = hypotl
31 31
32 32 /*
33 33 * long double hypotl(long double x, long double y);
34 34 * Method :
35 35 * If z=x*x+y*y has error less than sqrt(2)/2 ulp than sqrt(z) has
36 36 * error less than 1 ulp.
37 37 * So, compute sqrt(x*x+y*y) with some care as follows:
38 38 * Assume x>y>0;
39 39 * 1. save and set rounding to round-to-nearest
40 40 * 2. if x > 2y use
41 41 * x1*x1+(y*y+(x2*(x+x2))) for x*x+y*y
42 42 * where x1 = x with lower 64 bits cleared, x2 = x-x1; else
43 43 * 3. if x <= 2y use
44 44 * t1*y1+((x-y)*(x-y)+(t1*y2+t2*y))
45 45 * where t1 = 2x with lower 64 bits cleared, t2 = 2x-t1, y1= y with
46 46 * lower 64 bits chopped, y2 = y-y1.
47 47 *
48 48 * NOTE: DO NOT remove parenthsis!
49 49 *
50 50 * Special cases:
51 51 * hypot(x,y) is INF if x or y is +INF or -INF; else
52 52 * hypot(x,y) is NAN if x or y is NAN.
53 53 *
54 54 * Accuracy:
55 55 * hypot(x,y) returns sqrt(x^2+y^2) with error less than 1 ulps (units
56 56 * in the last place)
57 57 */
58 58
59 59 #include "libm.h"
60 60 #include "longdouble.h"
61 61
62 62 extern enum fp_direction_type __swapRD(enum fp_direction_type);
63 63
64 64 static const long double zero = 0.0L, one = 1.0L;
65 65
66 66 long double
67 67 hypotl(long double x, long double y) {
68 68 int n0, n1, n2, n3;
69 69 long double t1, t2, y1, y2, w;
70 70 int *px = (int *) &x, *py = (int *) &y;
71 71 int *pt1 = (int *) &t1, *py1 = (int *) &y1;
72 72 enum fp_direction_type rd;
73 73 int j, k, nx, ny, nz;
74 74
75 75 if ((*(int *) &one) != 0) { /* determine word ordering */
76 76 n0 = 0;
77 77 n1 = 1;
78 78 n2 = 2;
79 79 n3 = 3;
80 80 } else {
81 81 n0 = 3;
82 82 n1 = 2;
83 83 n2 = 1;
84 84 n3 = 0;
85 85 }
86 86
87 87 px[n0] &= 0x7fffffff; /* clear sign bit of x and y */
88 88 py[n0] &= 0x7fffffff;
89 89 k = 0x7fff0000;
90 90 nx = px[n0] & k; /* exponent of x and y */
91 91 ny = py[n0] & k;
92 92 if (ny > nx) {
93 93 w = x;
94 94 x = y;
95 95 y = w;
96 96 nz = ny;
97 97 ny = nx;
98 98 nx = nz;
99 99 } /* force x > y */
100 100 if ((nx - ny) >= 0x00730000)
101 101 return (x + y); /* x/y >= 2**116 */
102 102 if (nx < 0x5ff30000 && ny > 0x205b0000) { /* medium x,y */
103 103 /* save and set RD to Rounding to nearest */
104 104 rd = __swapRD(fp_nearest);
105 105 w = x - y;
106 106 if (w > y) {
107 107 pt1[n0] = px[n0];
108 108 pt1[n1] = px[n1];
109 109 pt1[n2] = pt1[n3] = 0;
110 110 t2 = x - t1;
111 111 x = sqrtl(t1 * t1 - (y * (-y) - t2 * (x + t1)));
112 112 } else {
113 113 x = x + x;
114 114 py1[n0] = py[n0];
115 115 py1[n1] = py[n1];
116 116 py1[n2] = py1[n3] = 0;
117 117 y2 = y - y1;
118 118 pt1[n0] = px[n0];
119 119 pt1[n1] = px[n1];
120 120 pt1[n2] = pt1[n3] = 0;
121 121 t2 = x - t1;
122 122 x = sqrtl(t1 * y1 - (w * (-w) - (t2 * y1 + y2 * x)));
123 123 }
124 124 if (rd != fp_nearest)
125 125 (void) __swapRD(rd); /* restore rounding mode */
126 126 return (x);
127 127 } else {
128 128 if (nx == k || ny == k) { /* x or y is INF or NaN */
129 129 if (isinfl(x))
130 130 t2 = x;
131 131 else if (isinfl(y))
132 132 t2 = y;
133 133 else
134 134 t2 = x + y; /* invalid if x or y is sNaN */
135 135 return (t2);
136 136 }
137 137 if (ny == 0) {
138 138 if (y == zero || x == zero)
139 139 return (x + y);
140 140 t1 = scalbnl(one, 16381);
141 141 x *= t1;
142 142 y *= t1;
143 143 return (scalbnl(one, -16381) * hypotl(x, y));
144 144 }
145 145 j = nx - 0x3fff0000;
146 146 px[n0] -= j;
147 147 py[n0] -= j;
148 148 pt1[n0] = nx;
149 149 pt1[n1] = pt1[n2] = pt1[n3] = 0;
150 150 return (t1 * hypotl(x, y));
151 151 }
152 152 }
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