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 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
23 */
24 /*
25 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 #pragma weak __tanf = tanf
30
31 #include "libm.h"
32
33 extern const int _TBL_ipio2_inf[];
34 extern int __rem_pio2m(double *, double *, int, int, int, const int *);
35 #if defined(__i386) && !defined(__amd64)
36 extern int __swapRP(int);
37 #endif
38
39 static const double C[] = {
40 1.0,
41 4.46066928428959230679140546271810308098793029785e-0003,
42 4.92165316309189027066395283327437937259674072266e+0000,
43 -7.11410648161473480044492134766187518835067749023e-0001,
44 4.08549808374053391446523164631798863410949707031e+0000,
45 2.50411070398050927821032018982805311679840087891e+0000,
46 1.11492064560251158411574579076841473579406738281e+0001,
47 -1.50565540968422650891511693771462887525558471680e+0000,
48 -1.81484378878349295050043110677506774663925170898e+0000,
49 3.333335997532835641297409611782510896641e-0001,
50 2.999997598248363761541668282006867229939e+00,
51 0.636619772367581343075535, /* 2^ -1 * 1.45F306DC9C883 */
52 0.5,
53 1.570796326734125614166, /* 2^ 0 * 1.921FB54400000 */
54 6.077100506506192601475e-11, /* 2^-34 * 1.0B4611A626331 */
55 };
56
57 #define one C[0]
58 #define P0 C[1]
59 #define P1 C[2]
60 #define P2 C[3]
61 #define P3 C[4]
62 #define P4 C[5]
63 #define P5 C[6]
64 #define P6 C[7]
65 #define P7 C[8]
66 #define T0 C[9]
67 #define T1 C[10]
68 #define invpio2 C[11]
69 #define half C[12]
70 #define pio2_1 C[13]
71 #define pio2_t C[14]
72
73 float
74 tanf(float x)
75 {
76 double y, z, w;
77 float f;
78 int n, ix, hx, hy;
79 volatile int i;
80
81 hx = *((int *)&x);
82 ix = hx & 0x7fffffff;
83
84 y = (double)x;
85
86 if (ix <= 0x4016cbe4) { /* |x| < 3*pi/4 */
87 if (ix <= 0x3f490fdb) { /* |x| < pi/4 */
88 if (ix < 0x3c000000) { /* |x| < 2**-7 */
89 if (ix <= 0x39800000) { /* |x| < 2**-12 */
90 i = (int)y;
91 #ifdef lint
92 i = i;
93 #endif
94 return (x);
95 }
96 return ((float)((y * T0) * (T1 + y * y)));
97 }
98 z = y * y;
99 return ((float)(((P0 * y) * (P1 + z * (P2 + z)) *
100 (P3 + z * (P4 + z))) *
101 (P5 + z * (P6 + z * (P7 + z)))));
102 }
103 if (hx > 0)
104 y = (y - pio2_1) - pio2_t;
105 else
106 y = (y + pio2_1) + pio2_t;
107 hy = ((int *)&y)[HIWORD] & ~0x80000000;
108 if (hy < 0x3f800000) { /* |y| < 2**-7 */
109 z = (y * T0) * (T1 + y * y);
110 return ((float)(-one / z));
111 }
112 z = y * y;
113 w = ((P0 * y) * (P1 + z * (P2 + z)) * (P3 + z * (P4 + z))) *
114 (P5 + z * (P6 + z * (P7 + z)));
115 return ((float)(-one / w));
116 }
117
118 if (ix <= 0x49c90fdb) { /* |x| < 2^19*pi */
119 #if defined(__i386) && !defined(__amd64)
120 int rp;
121
122 rp = __swapRP(fp_extended);
123 #endif
124 w = y * invpio2;
125 if (hx < 0)
126 n = (int)(w - half);
127 else
128 n = (int)(w + half);
129 y = (y - n * pio2_1) - n * pio2_t;
130 #if defined(__i386) && !defined(__amd64)
131 if (rp != fp_extended)
132 (void) __swapRP(rp);
133 #endif
134 } else {
135 if (ix >= 0x7f800000)
136 return (x / x); /* sin(Inf or NaN) is NaN */
137 hy = ((int *)&y)[HIWORD];
138 n = ((hy >> 20) & 0x7ff) - 1046;
139 ((int *)&w)[HIWORD] = (hy & 0xfffff) | 0x41600000;
140 ((int *)&w)[LOWORD] = ((int *)&y)[LOWORD];
141 n = __rem_pio2m(&w, &y, n, 1, 0, _TBL_ipio2_inf);
142 if (hy < 0) {
143 y = -y;
144 n = -n;
145 }
146 }
147
148 hy = ((int *)&y)[HIWORD] & ~0x80000000;
149 if (hy < 0x3f800000) { /* |y| < 2**-7 */
150 z = (y * T0) * (T1 + y * y);
151 f = ((n & 1) == 0)? (float)z : (float)(-one / z);
152 return (f);
153 }
154 z = y * y;
155 w = ((P0 * y) * (P1 + z * (P2 + z)) * (P3 + z * (P4 + z))) *
156 (P5 + z * (P6 + z * (P7 + z)));
157 f = ((n & 1) == 0)? (float)w : (float)(-one / w);
158 return (f);
159 }