1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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 /*
23 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
24 */
25
26 /*
27 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30
31 #pragma weak __tanf = tanf
32
33 #include "libm.h"
34
35 extern const int _TBL_ipio2_inf[];
36 extern int __rem_pio2m(double *, double *, int, int, int, const int *);
37
38 #if defined(__i386) && !defined(__amd64)
39 extern int __swapRP(int);
40 #endif
41
42 static const double C[] = {
43 1.0,
44 4.46066928428959230679140546271810308098793029785e-0003,
45 4.92165316309189027066395283327437937259674072266e+0000,
46 -7.11410648161473480044492134766187518835067749023e-0001,
47 4.08549808374053391446523164631798863410949707031e+0000,
48 2.50411070398050927821032018982805311679840087891e+0000,
49 1.11492064560251158411574579076841473579406738281e+0001,
50 -1.50565540968422650891511693771462887525558471680e+0000,
51 -1.81484378878349295050043110677506774663925170898e+0000,
52 3.333335997532835641297409611782510896641e-0001,
53 2.999997598248363761541668282006867229939e+00,
54 0.636619772367581343075535, /* 2^ -1 * 1.45F306DC9C883 */
55 0.5,
56 1.570796326734125614166, /* 2^ 0 * 1.921FB54400000 */
57 6.077100506506192601475e-11, /* 2^-34 * 1.0B4611A626331 */
58 };
59
60 #define one C[0]
61 #define P0 C[1]
62 #define P1 C[2]
63 #define P2 C[3]
64 #define P3 C[4]
65 #define P4 C[5]
66 #define P5 C[6]
67 #define P6 C[7]
68 #define P7 C[8]
69 #define T0 C[9]
70 #define T1 C[10]
71 #define invpio2 C[11]
72 #define half C[12]
73 #define pio2_1 C[13]
74 #define pio2_t C[14]
75
76 float
77 tanf(float x)
78 {
79 double y, z, w;
80 float f;
81 int n, ix, hx, hy;
82 volatile int i __unused;
83
84 hx = *((int *)&x);
85 ix = hx & 0x7fffffff;
86
87 y = (double)x;
88
89 if (ix <= 0x4016cbe4) { /* |x| < 3*pi/4 */
90 if (ix <= 0x3f490fdb) { /* |x| < pi/4 */
91 if (ix < 0x3c000000) { /* |x| < 2**-7 */
92 if (ix <= 0x39800000) { /* |x| < 2**-12 */
93 i = (int)y;
94 #ifdef lint
95 i = i;
96 #endif
97 return (x);
98 }
99
100 return ((float)((y * T0) * (T1 + y * y)));
101 }
102
103 z = y * y;
104 return ((float)(((P0 * y) * (P1 + z * (P2 + z)) * (P3 +
105 z * (P4 + z))) * (P5 + z * (P6 + z *
106 (P7 + z)))));
107 }
108
109 if (hx > 0)
110 y = (y - pio2_1) - pio2_t;
111 else
112 y = (y + pio2_1) + pio2_t;
113
114 hy = ((int *)&y)[HIWORD] & ~0x80000000;
115
116 if (hy < 0x3f800000) { /* |y| < 2**-7 */
117 z = (y * T0) * (T1 + y * y);
118 return ((float)(-one / z));
119 }
120
121 z = y * y;
122 w = ((P0 * y) * (P1 + z * (P2 + z)) * (P3 + z * (P4 + z))) *
123 (P5 + z * (P6 + z * (P7 + z)));
124 return ((float)(-one / w));
125 }
126
127 if (ix <= 0x49c90fdb) { /* |x| < 2^19*pi */
128 #if defined(__i386) && !defined(__amd64)
129 int rp;
130
131 rp = __swapRP(fp_extended);
132 #endif
133 w = y * invpio2;
134
135 if (hx < 0)
136 n = (int)(w - half);
137 else
138 n = (int)(w + half);
139
140 y = (y - n * pio2_1) - n * pio2_t;
141 #if defined(__i386) && !defined(__amd64)
142 if (rp != fp_extended)
143 (void) __swapRP(rp);
144 #endif
145 } else {
146 if (ix >= 0x7f800000)
147 return (x / x); /* sin(Inf or NaN) is NaN */
148
149 hy = ((int *)&y)[HIWORD];
150 n = ((hy >> 20) & 0x7ff) - 1046;
151 ((int *)&w)[HIWORD] = (hy & 0xfffff) | 0x41600000;
152 ((int *)&w)[LOWORD] = ((int *)&y)[LOWORD];
153 n = __rem_pio2m(&w, &y, n, 1, 0, _TBL_ipio2_inf);
154
155 if (hy < 0) {
156 y = -y;
157 n = -n;
158 }
159 }
160
161 hy = ((int *)&y)[HIWORD] & ~0x80000000;
162
163 if (hy < 0x3f800000) { /* |y| < 2**-7 */
164 z = (y * T0) * (T1 + y * y);
165 f = ((n & 1) == 0) ? (float)z : (float)(-one / z);
166 return (f);
167 }
168
169 z = y * y;
170 w = ((P0 * y) * (P1 + z * (P2 + z)) * (P3 + z * (P4 + z))) * (P5 + z *
171 (P6 + z * (P7 + z)));
172 f = ((n & 1) == 0) ? (float)w : (float)(-one / w);
173 return (f);
174 }