xref: /titanic_41/usr/src/lib/libm/common/Q/__sincosl.c (revision 5b2ba9d3d1e04dde804c89e9879f7dfc9bcebf61)
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  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 /*
31  * long double __k_sincos(long double x, long double y, long double *c);
32  * kernel sincosl function on [-pi/4, pi/4], pi/4 ~ 0.785398164
33  * Input x is assumed to be bounded by ~pi/4 in magnitude.
34  * Input y is the tail of x.
35  * return sinl(x) with *c = cosl(x)
36  *
37  * Table look up algorithm
38  *	see __k_sinl and __k_cosl
39  */
40 
41 #include "libm.h"
42 
43 extern const long double _TBL_sinl_hi[], _TBL_sinl_lo[],
44 	_TBL_cosl_hi[], _TBL_cosl_lo[];
45 static const long double
46 	one	= 1.0L,
47 /*
48  *                   3           11       -122.32
49  * |sin(x) - (x+pp1*x +...+ pp5*x  )| <= 2        for |x|<1/64
50  */
51 	pp1	= -1.666666666666666666666666666586782940810e-0001L,
52 	pp2	= +8.333333333333333333333003723660929317540e-0003L,
53 	pp3	= -1.984126984126984076045903483778337804470e-0004L,
54 	pp4	= +2.755731922361906641319723106210900949413e-0006L,
55 	pp5	= -2.505198398570947019093998469135012057673e-0008L,
56 /*
57  * |(sin(x) - (x+p1*x^3+...+p8*x^17)|
58  * |------------------------------- | <= 2^-116.17 for |x|<0.1953125
59  * |                 x              |
60  */
61 	p1	= -1.666666666666666666666666666666211262297e-0001L,
62 	p2	= +8.333333333333333333333333301497876908541e-0003L,
63 	p3	= -1.984126984126984126984041302881180621922e-0004L,
64 	p4	= +2.755731922398589064100587351307269621093e-0006L,
65 	p5	= -2.505210838544163129378906953765595393873e-0008L,
66 	p6	= +1.605904383643244375050998243778534074273e-0010L,
67 	p7	= -7.647162722800685516901456114270824622699e-0013L,
68 	p8	= +2.810046428661902961725428841068844462603e-0015L,
69 /*
70  *                   2           10       -123.84
71  * |cos(x) - (1+qq1*x +...+ qq5*x  )| <= 2        for |x|<=1/128
72  */
73 	qq1	= -4.999999999999999999999999999999378373641e-0001L,
74 	qq2	= +4.166666666666666666666665478399327703130e-0002L,
75 	qq3	= -1.388888888888888888058211230618051613494e-0003L,
76 	qq4	= +2.480158730156105377771585658905303111866e-0005L,
77 	qq5	= -2.755728099762526325736488376695157008736e-0007L,
78 /*
79  *                  2            16       -117.11
80  * |cos(x) - (1+q1*x + ... + q8*x  )| <= 2        for |x|<= 0.15625
81  */
82 	q1	= -4.999999999999999999999999999999756416975e-0001L,
83 	q2	= +4.166666666666666666666666664006066577258e-0002L,
84 	q3	= -1.388888888888888888888877700363937169637e-0003L,
85 	q4	= +2.480158730158730158494468463031814083559e-0005L,
86 	q5	= -2.755731922398586276322819250356005542871e-0007L,
87 	q6	= +2.087675698767424261441959760729854017855e-0009L,
88 	q7	= -1.147074481239662089072452129010790774761e-0011L,
89 	q8	= +4.777761647399651599730663422263531034782e-0014L;
90 
91 #define	i0	0
92 
93 long double
__k_sincosl(long double x,long double y,long double * c)94 __k_sincosl(long double x, long double y, long double *c) {
95 	long double a1, a2, t, t1, t2, z, w;
96 	int *pt = (int *) &t, *px = (int *) &x;
97 	int i, j, hx, ix;
98 
99 	t = 1.0L;
100 	hx = px[i0];
101 	ix = hx & 0x7fffffff;
102 	if (ix < 0x3ffc4000) {
103 		if (ix < 0x3fc60000)
104 			if (((int) x) == 0) {
105 				*c = one;
106 				return (x);
107 			}	/* generate inexact */
108 		z = x * x;
109 
110 		if (ix < 0x3ff80000) {
111 			*c = one + z * (qq1 + z * (qq2 + z * (qq3 +
112 				z * (qq4 + z * qq5))));
113 			t = z * (p1 + z * (p2 + z * (p3 + z * (p4 +
114 				z * (p5 + z * p6)))));
115 		} else {
116 			*c = one + z * (q1 + z * (q2 + z * (q3 + z * (q4 +
117 				z * (q5 + z * (q6 + z * (q7 + z * q8)))))));
118 			t = z * (p1 + z * (p2 + z * (p3 + z * (p4 + z * (p5 +
119 				z * (p6 + z * (p7 + z * p8)))))));
120 		}
121 
122 		t = y + x * t;
123 		return (x + t);
124 	}
125 	j = (ix + 0x400) & 0x7ffff800;
126 	i = (j - 0x3ffc4000) >> 11;
127 	pt[i0] = j;
128 	if (hx > 0)
129 		x = y - (t - x);
130 	else
131 		x = (-y) - (t + x);
132 	a1 = _TBL_sinl_hi[i];
133 	z = x * x;
134 	t = z * (qq1 + z * (qq2 + z * (qq3 + z * (qq4 + z * qq5))));
135 	w = x * (one + z * (pp1 + z * (pp2 + z * (pp3 + z * (pp4 + z * pp5)))));
136 	a2 = _TBL_cosl_hi[i];
137 	t2 = _TBL_cosl_lo[i] - (a1 * w - a2 * t);
138 	*c = a2 + t2;
139 	t1 = a2 * w + a1 * t;
140 	t1 += _TBL_sinl_lo[i];
141 	if (hx < 0)
142 		return (-a1 - t1);
143 	else
144 		return (a1 + t1);
145 }
146