xref: /freebsd/lib/msun/src/s_sinl.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*-
2  * Copyright (c) 2007 Steven G. Kargl
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice unmodified, this list of conditions, and the following
10  *    disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <float.h>
31 
32 #include "math.h"
33 #include "math_private.h"
34 #if LDBL_MANT_DIG == 64
35 #include "../ld80/e_rem_pio2l.h"
36 #elif LDBL_MANT_DIG == 113
37 #include "../ld128/e_rem_pio2l.h"
38 #else
39 #error "Unsupported long double format"
40 #endif
41 
42 long double
43 sinl(long double x)
44 {
45 	union IEEEl2bits z;
46 	int e0, s;
47 	long double y[2];
48 	long double hi, lo;
49 
50 	z.e = x;
51 	s = z.bits.sign;
52 	z.bits.sign = 0;
53 
54 	/* If x = +-0 or x is a subnormal number, then sin(x) = x */
55 	if (z.bits.exp == 0)
56 		return (x);
57 
58 	/* If x = NaN or Inf, then sin(x) = NaN. */
59 	if (z.bits.exp == 32767)
60 		return ((x - x) / (x - x));
61 
62 	/* Optimize the case where x is already within range. */
63 	if (z.e < M_PI_4) {
64 		hi = __kernel_sinl(z.e, 0, 0);
65 		return  (s ? -hi : hi);
66 	}
67 
68 	e0 = __ieee754_rem_pio2l(x, y);
69 	hi = y[0];
70 	lo = y[1];
71 
72 	switch (e0 & 3) {
73 	case 0:
74 	    hi = __kernel_sinl(hi, lo, 1);
75 	    break;
76 	case 1:
77 	    hi = __kernel_cosl(hi, lo);
78 	    break;
79 	case 2:
80 	    hi = - __kernel_sinl(hi, lo, 1);
81 	    break;
82 	case 3:
83 	    hi = - __kernel_cosl(hi, lo);
84 	    break;
85 	}
86 
87 	return (hi);
88 }
89