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 __cosf = cosf
30
31/*
32 * See sincosf.c
33 */
34
35#include "libm.h"
36
37extern const int _TBL_ipio2_inf[];
38extern int __rem_pio2m(double *, double *, int, int, int, const int *);
39#if defined(__i386) && !defined(__amd64)
40extern int __swapRP(int);
41#endif
42
43static 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
73float
74cosf(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 (1.0f);
94			}
95			z = y * y;
96			return ((float)(((C0 + z * C1) + (z * z) * C2) *
97			    (C3 + z * (C4 + z))));
98		} else if (hx > 0) {
99			y = (y - pio2_1) - pio2_t;
100			z = y * y;
101			return ((float)-((y * (S0 + z * S1)) *
102			    (S2 + z * (S3 + z))));
103		} else {
104			y = (y + pio2_1) + pio2_t;
105			z = y * y;
106			return ((float)((y * (S0 + z * S1)) *
107			    (S2 + z * (S3 + 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		n++;
122#if defined(__i386) && !defined(__amd64)
123		if (rp != fp_extended)
124			(void) __swapRP(rp);
125#endif
126	} else {
127		if (ix >= 0x7f800000)
128			return (x / x); /* cos(Inf or NaN) is NaN */
129		hy = ((int *)&y)[HIWORD];
130		n = ((hy >> 20) & 0x7ff) - 1046;
131		((int *)&w)[HIWORD] = (hy & 0xfffff) | 0x41600000;
132		((int *)&w)[LOWORD] = ((int *)&y)[LOWORD];
133		n = __rem_pio2m(&w, &y, n, 1, 0, _TBL_ipio2_inf) + 1;
134	}
135
136	if (n & 1) {
137		/* compute cos y */
138		z = y * y;
139		f = (float)(((C0 + z * C1) + (z * z) * C2) *
140		    (C3 + z * (C4 + z)));
141	} else {
142		/* compute sin y */
143		z = y * y;
144		f = (float)((y * (S0 + z * S1)) * (S2 + z * (S3 + z)));
145	}
146
147	return ((n & 2)? -f : f);
148}
149