xref: /freebsd/lib/msun/src/s_sinl.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 <float.h>
30 #ifdef __i386__
31 #include <ieeefp.h>
32 #endif
33 
34 #include "math.h"
35 #include "math_private.h"
36 #if LDBL_MANT_DIG == 64
37 #include "../ld80/e_rem_pio2l.h"
38 #elif LDBL_MANT_DIG == 113
39 #include "../ld128/e_rem_pio2l.h"
40 #else
41 #error "Unsupported long double format"
42 #endif
43 
44 long double
45 sinl(long double x)
46 {
47 	union IEEEl2bits z;
48 	int e0, s;
49 	long double y[2];
50 	long double hi, lo;
51 
52 	z.e = x;
53 	s = z.bits.sign;
54 	z.bits.sign = 0;
55 
56 	/* If x = +-0 or x is a subnormal number, then sin(x) = x */
57 	if (z.bits.exp == 0)
58 		return (x);
59 
60 	/* If x = NaN or Inf, then sin(x) = NaN. */
61 	if (z.bits.exp == 32767)
62 		return ((x - x) / (x - x));
63 
64 	ENTERI();
65 
66 	/* Optimize the case where x is already within range. */
67 	if (z.e < M_PI_4) {
68 		hi = __kernel_sinl(z.e, 0, 0);
69 		RETURNI(s ? -hi : hi);
70 	}
71 
72 	e0 = __ieee754_rem_pio2l(x, y);
73 	hi = y[0];
74 	lo = y[1];
75 
76 	switch (e0 & 3) {
77 	case 0:
78 	    hi = __kernel_sinl(hi, lo, 1);
79 	    break;
80 	case 1:
81 	    hi = __kernel_cosl(hi, lo);
82 	    break;
83 	case 2:
84 	    hi = - __kernel_sinl(hi, lo, 1);
85 	    break;
86 	case 3:
87 	    hi = - __kernel_cosl(hi, lo);
88 	    break;
89 	}
90 
91 	RETURNI(hi);
92 }
93