Print this page
11210 libm should be cstyle(1ONBLD) clean
| Split |
Close |
| Expand all |
| Collapse all |
--- 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.
|
↓ open down ↓ |
14 lines elided |
↑ open up ↑ |
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 27 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
27 28 * Use is subject to license terms.
28 29 */
29 30
30 31 #pragma weak __hypotl = hypotl
31 32
32 33 /*
33 34 * long double hypotl(long double x, long double y);
34 35 * Method :
35 36 * If z=x*x+y*y has error less than sqrt(2)/2 ulp than sqrt(z) has
36 37 * error less than 1 ulp.
37 38 * So, compute sqrt(x*x+y*y) with some care as follows:
38 39 * Assume x>y>0;
39 40 * 1. save and set rounding to round-to-nearest
40 41 * 2. if x > 2y use
41 42 * x1*x1+(y*y+(x2*(x+x2))) for x*x+y*y
42 43 * where x1 = x with lower 64 bits cleared, x2 = x-x1; else
43 44 * 3. if x <= 2y use
44 45 * t1*y1+((x-y)*(x-y)+(t1*y2+t2*y))
|
↓ open down ↓ |
10 lines elided |
↑ open up ↑ |
45 46 * where t1 = 2x with lower 64 bits cleared, t2 = 2x-t1, y1= y with
46 47 * lower 64 bits chopped, y2 = y-y1.
47 48 *
48 49 * NOTE: DO NOT remove parenthsis!
49 50 *
50 51 * Special cases:
51 52 * hypot(x,y) is INF if x or y is +INF or -INF; else
52 53 * hypot(x,y) is NAN if x or y is NAN.
53 54 *
54 55 * Accuracy:
55 - * hypot(x,y) returns sqrt(x^2+y^2) with error less than 1 ulps (units
56 + * hypot(x,y) returns sqrt(x^2+y^2) with error less than 1 ulps (units
56 57 * in the last place)
57 58 */
58 59
59 60 #include "libm.h"
60 61 #include "longdouble.h"
61 62
62 63 extern enum fp_direction_type __swapRD(enum fp_direction_type);
63 64
64 65 static const long double zero = 0.0L, one = 1.0L;
65 -
66 66 long double
67 -hypotl(long double x, long double y) {
67 +hypotl(long double x, long double y)
68 +{
68 69 int n0, n1, n2, n3;
69 70 long double t1, t2, y1, y2, w;
70 - int *px = (int *) &x, *py = (int *) &y;
71 - int *pt1 = (int *) &t1, *py1 = (int *) &y1;
71 + int *px = (int *)&x, *py = (int *)&y;
72 + int *pt1 = (int *)&t1, *py1 = (int *)&y1;
72 73 enum fp_direction_type rd;
73 74 int j, k, nx, ny, nz;
74 75
75 - if ((*(int *) &one) != 0) { /* determine word ordering */
76 + if ((*(int *)&one) != 0) { /* determine word ordering */
76 77 n0 = 0;
77 78 n1 = 1;
78 79 n2 = 2;
79 80 n3 = 3;
80 81 } else {
81 82 n0 = 3;
82 83 n1 = 2;
83 84 n2 = 1;
84 85 n3 = 0;
85 86 }
86 87
87 - px[n0] &= 0x7fffffff; /* clear sign bit of x and y */
88 + px[n0] &= 0x7fffffff; /* clear sign bit of x and y */
88 89 py[n0] &= 0x7fffffff;
89 90 k = 0x7fff0000;
90 - nx = px[n0] & k; /* exponent of x and y */
91 + nx = px[n0] & k; /* exponent of x and y */
91 92 ny = py[n0] & k;
93 +
92 94 if (ny > nx) {
93 95 w = x;
94 96 x = y;
95 97 y = w;
96 98 nz = ny;
97 99 ny = nx;
98 100 nx = nz;
99 - } /* force x > y */
101 + } /* force x > y */
102 +
100 103 if ((nx - ny) >= 0x00730000)
101 104 return (x + y); /* x/y >= 2**116 */
105 +
102 106 if (nx < 0x5ff30000 && ny > 0x205b0000) { /* medium x,y */
103 107 /* save and set RD to Rounding to nearest */
104 108 rd = __swapRD(fp_nearest);
105 109 w = x - y;
110 +
106 111 if (w > y) {
107 112 pt1[n0] = px[n0];
108 113 pt1[n1] = px[n1];
109 114 pt1[n2] = pt1[n3] = 0;
110 115 t2 = x - t1;
111 116 x = sqrtl(t1 * t1 - (y * (-y) - t2 * (x + t1)));
112 117 } else {
113 118 x = x + x;
114 119 py1[n0] = py[n0];
115 120 py1[n1] = py[n1];
116 121 py1[n2] = py1[n3] = 0;
117 122 y2 = y - y1;
118 123 pt1[n0] = px[n0];
119 124 pt1[n1] = px[n1];
120 125 pt1[n2] = pt1[n3] = 0;
121 126 t2 = x - t1;
122 127 x = sqrtl(t1 * y1 - (w * (-w) - (t2 * y1 + y2 * x)));
123 128 }
129 +
124 130 if (rd != fp_nearest)
125 131 (void) __swapRD(rd); /* restore rounding mode */
132 +
126 133 return (x);
127 134 } else {
128 135 if (nx == k || ny == k) { /* x or y is INF or NaN */
129 136 if (isinfl(x))
130 137 t2 = x;
131 138 else if (isinfl(y))
132 139 t2 = y;
133 140 else
134 141 t2 = x + y; /* invalid if x or y is sNaN */
142 +
135 143 return (t2);
136 144 }
145 +
137 146 if (ny == 0) {
138 147 if (y == zero || x == zero)
139 148 return (x + y);
149 +
140 150 t1 = scalbnl(one, 16381);
141 151 x *= t1;
142 152 y *= t1;
143 153 return (scalbnl(one, -16381) * hypotl(x, y));
144 154 }
155 +
145 156 j = nx - 0x3fff0000;
146 157 px[n0] -= j;
147 158 py[n0] -= j;
148 159 pt1[n0] = nx;
149 160 pt1[n1] = pt1[n2] = pt1[n3] = 0;
150 161 return (t1 * hypotl(x, y));
151 162 }
152 163 }
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX