xref: /freebsd/lib/msun/src/s_sinl.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007 Steven G. Kargl
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <float.h>
33 #ifdef __i386__
34 #include <ieeefp.h>
35 #endif
36 
37 #include "math.h"
38 #include "math_private.h"
39 #if LDBL_MANT_DIG == 64
40 #include "../ld80/e_rem_pio2l.h"
41 #elif LDBL_MANT_DIG == 113
42 #include "../ld128/e_rem_pio2l.h"
43 #else
44 #error "Unsupported long double format"
45 #endif
46 
47 long double
48 sinl(long double x)
49 {
50 	union IEEEl2bits z;
51 	int e0, s;
52 	long double y[2];
53 	long double hi, lo;
54 
55 	z.e = x;
56 	s = z.bits.sign;
57 	z.bits.sign = 0;
58 
59 	/* If x = +-0 or x is a subnormal number, then sin(x) = x */
60 	if (z.bits.exp == 0)
61 		return (x);
62 
63 	/* If x = NaN or Inf, then sin(x) = NaN. */
64 	if (z.bits.exp == 32767)
65 		return ((x - x) / (x - x));
66 
67 	ENTERI();
68 
69 	/* Optimize the case where x is already within range. */
70 	if (z.e < M_PI_4) {
71 		hi = __kernel_sinl(z.e, 0, 0);
72 		RETURNI(s ? -hi : hi);
73 	}
74 
75 	e0 = __ieee754_rem_pio2l(x, y);
76 	hi = y[0];
77 	lo = y[1];
78 
79 	switch (e0 & 3) {
80 	case 0:
81 	    hi = __kernel_sinl(hi, lo, 1);
82 	    break;
83 	case 1:
84 	    hi = __kernel_cosl(hi, lo);
85 	    break;
86 	case 2:
87 	    hi = - __kernel_sinl(hi, lo, 1);
88 	    break;
89 	case 3:
90 	    hi = - __kernel_cosl(hi, lo);
91 	    break;
92 	}
93 
94 	RETURNI(hi);
95 }
96