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 <float.h>
16
17 #include "math.h"
18 #define INLINE_REM_PIO2
19 #include "math_private.h"
20 #include "e_rem_pio2.c"
21 #include "k_sincos.h"
22
23 void
sincos(double x,double * sn,double * cs)24 sincos(double x, double *sn, double *cs)
25 {
26 double y[2];
27 int32_t n, ix;
28
29 /* High word of x. */
30 GET_HIGH_WORD(ix, x);
31
32 /* |x| ~< pi/4 */
33 ix &= 0x7fffffff;
34 if (ix <= 0x3fe921fb) {
35 if (ix < 0x3e400000) { /* |x| < 2**-27 */
36 if ((int)x == 0) { /* Generate inexact. */
37 *sn = x;
38 *cs = 1;
39 return;
40 }
41 }
42 __kernel_sincos(x, 0, 0, sn, cs);
43 return;
44 }
45
46 /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
47 if (ix >= 0x7ff00000) {
48 *sn = x - x;
49 *cs = x - x;
50 return;
51 }
52
53 /* Argument reduction. */
54 n = __ieee754_rem_pio2(x, y);
55
56 switch(n & 3) {
57 case 0:
58 __kernel_sincos(y[0], y[1], 1, sn, cs);
59 break;
60 case 1:
61 __kernel_sincos(y[0], y[1], 1, cs, sn);
62 *cs = -*cs;
63 break;
64 case 2:
65 __kernel_sincos(y[0], y[1], 1, sn, cs);
66 *sn = -*sn;
67 *cs = -*cs;
68 break;
69 default:
70 __kernel_sincos(y[0], y[1], 1, cs, sn);
71 *sn = -*sn;
72 }
73 }
74
75 #if (LDBL_MANT_DIG == 53)
76 __weak_reference(sincos, sincosl);
77 #endif
78