xref: /illumos-gate/usr/src/lib/libm/common/R/sinf.c (revision 862246c1516ca78c11bef09650987f3d7171b2c9)
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 __sinf = sinf
30 
31 /*
32  * See sincosf.c
33  */
34 
35 #include "libm.h"
36 
37 extern const int _TBL_ipio2_inf[];
38 extern int __rem_pio2m(double *, double *, int, int, int, const int *);
39 #if defined(__i386) && !defined(__amd64)
40 extern int __swapRP(int);
41 #endif
42 
43 static const double C[] = {
44 	1.85735322054308378716204874632872525989806770558e-0003,
45 	-1.95035094218403635082921458859320791358115801259e-0004,
46 	5.38400550766074785970952495168558701485841707252e+0002,
47 	-3.31975110777873728964197739157371509422022905947e+0001,
48 	1.09349482127188401868272000389539985058873853699e-0003,
49 	-5.03324285989964979398034700054920226866107675091e-0004,
50 	2.43792880266971107750418061559602239831538067410e-0005,
51 	9.14499072605666582228127405245558035523741471271e+0002,
52 	-3.63151270591815439197122504991683846785293207730e+0001,
53 	0.636619772367581343075535,	/* 2^ -1  * 1.45F306DC9C883 */
54 	0.5,
55 	1.570796326734125614166,	/* 2^  0  * 1.921FB54400000 */
56 	6.077100506506192601475e-11,	/* 2^-34  * 1.0B4611A626331 */
57 };
58 
59 #define	S0	C[0]
60 #define	S1	C[1]
61 #define	S2	C[2]
62 #define	S3	C[3]
63 #define	C0	C[4]
64 #define	C1	C[5]
65 #define	C2	C[6]
66 #define	C3	C[7]
67 #define	C4	C[8]
68 #define	invpio2	C[9]
69 #define	half	C[10]
70 #define	pio2_1  C[11]
71 #define	pio2_t	C[12]
72 
73 float
sinf(float x)74 sinf(float x)
75 {
76 	double	y, z, w;
77 	float	f;
78 	int	n, ix, hx, hy;
79 	volatile int i __unused;
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 <= 0x39800000) {	/* |x| <= 2**-12 */
89 				i = (int)y;
90 #ifdef lint
91 				i = i;
92 #endif
93 				return (x);
94 			}
95 			z = y * y;
96 			return ((float)((y * (S0 + z * S1)) *
97 			    (S2 + z * (S3 + z))));
98 		} else if (hx > 0) {
99 			y = (y - pio2_1) - pio2_t;
100 			z = y * y;
101 			return ((float)(((C0 + z * C1) + (z * z) * C2) *
102 			    (C3 + z * (C4 + z))));
103 		} else {
104 			y = (y + pio2_1) + pio2_t;
105 			z = y * y;
106 			return ((float)-(((C0 + z * C1) + (z * z) * C2) *
107 			    (C3 + z * (C4 + z))));
108 		}
109 	} else if (ix <= 0x49c90fdb) {	/* |x| < 2^19*pi */
110 #if defined(__i386) && !defined(__amd64)
111 		int	rp;
112 
113 		rp = __swapRP(fp_extended);
114 #endif
115 		w = y * invpio2;
116 		if (hx < 0)
117 			n = (int)(w - half);
118 		else
119 			n = (int)(w + half);
120 		y = (y - n * pio2_1) - n * pio2_t;
121 #if defined(__i386) && !defined(__amd64)
122 		if (rp != fp_extended)
123 			(void) __swapRP(rp);
124 #endif
125 	} else {
126 		if (ix >= 0x7f800000)
127 			return (x / x);	/* sin(Inf or NaN) is NaN */
128 		hy = ((int *)&y)[HIWORD];
129 		n = ((hy >> 20) & 0x7ff) - 1046;
130 		((int *)&w)[HIWORD] = (hy & 0xfffff) | 0x41600000;
131 		((int *)&w)[LOWORD] = ((int *)&y)[LOWORD];
132 		n = __rem_pio2m(&w, &y, n, 1, 0, _TBL_ipio2_inf);
133 		if (hy < 0) {
134 			y = -y;
135 			n = -n;
136 		}
137 	}
138 
139 	if (n & 1) {
140 		/* compute cos y */
141 		z = y * y;
142 		f = (float)(((C0 + z * C1) + (z * z) * C2) *
143 		    (C3 + z * (C4 + z)));
144 	} else {
145 		/* compute sin y */
146 		z = y * y;
147 		f = (float)((y * (S0 + z * S1)) * (S2 + z * (S3 + z)));
148 	}
149 
150 	return ((n & 2)? -f : f);
151 }
152