1 /*-
2 * ====================================================
3 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
4 *
5 * Developed at SunPro, a Sun Microsystems, Inc. business.
6 * Permission to use, copy, modify, and distribute this
7 * software is freely granted, provided that this notice
8 * is preserved.
9 * ====================================================
10 *
11 * s_sin.c and s_cos.c merged by Steven G. Kargl. Descriptions of the
12 * algorithms are contained in the original files.
13 */
14
15 #include <sys/cdefs.h>
16 #if defined(LIBM_SCCS) && !defined(lint)
17 __RCSID("$NetBSD: s_sincos.c,v 1.5 2022/08/29 01:48:34 riastradh Exp $");
18 #endif
19 #if 0
20 __FBSDID("$FreeBSD: head/lib/msun/src/s_sincos.c 319047 2017-05-28 06:13:38Z mmel $");
21 #endif
22
23 #include "namespace.h"
24 #include <float.h>
25
26 #include "math.h"
27 // #define INLINE_REM_PIO2
28 #include "math_private.h"
29 // #include "e_rem_pio2.c"
30 #include "k_sincos.h"
31
32 #ifdef __weak_alias
__weak_alias(sincos,_sincos)33 __weak_alias(sincos,_sincos)
34 #endif
35
36 void
37 sincos(double x, double *sn, double *cs)
38 {
39 double y[2];
40 int32_t n, ix;
41
42 /* High word of x. */
43 GET_HIGH_WORD(ix, x);
44
45 /* |x| ~< pi/4 */
46 ix &= 0x7fffffff;
47 if (ix <= 0x3fe921fb) {
48 if (ix < 0x3e400000) { /* |x| < 2**-27 */
49 if ((int)x == 0) { /* Generate inexact. */
50 *sn = x;
51 *cs = 1;
52 return;
53 }
54 }
55 __kernel_sincos(x, 0, 0, sn, cs);
56 return;
57 }
58
59 /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
60 if (ix >= 0x7ff00000) {
61 *sn = x - x;
62 *cs = x - x;
63 return;
64 }
65
66 /* Argument reduction. */
67 n = __ieee754_rem_pio2(x, y);
68
69 switch(n & 3) {
70 case 0:
71 __kernel_sincos(y[0], y[1], 1, sn, cs);
72 break;
73 case 1:
74 __kernel_sincos(y[0], y[1], 1, cs, sn);
75 *cs = -*cs;
76 break;
77 case 2:
78 __kernel_sincos(y[0], y[1], 1, sn, cs);
79 *sn = -*sn;
80 *cs = -*cs;
81 break;
82 default:
83 __kernel_sincos(y[0], y[1], 1, cs, sn);
84 *sn = -*sn;
85 }
86 }
87
88 #if !defined(__HAVE_LONG_DOUBLE)
89 __weak_alias(sincosl, sincos);
90 #endif
91