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
12 /* s_sincosf.c -- float version of s_sincos.c.
13 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
14 * Optimized by Bruce D. Evans.
15 * Merged s_sinf.c and s_cosf.c by Steven G. Kargl.
16 */
17
18 #include <float.h>
19 #include "math.h"
20
21 #include "math_private.h"
22 #include "k_sincosf.h"
23
24 /* Small multiples of pi/2 rounded to double precision. */
25 static const double
26 p1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
27 p2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
28 p3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
29 p4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
30
31 void
sincosf(float x,float * sn,float * cs)32 sincosf(float x, float *sn, float *cs)
33 {
34 float c, s;
35 float y[2];
36 int32_t n, hx, ix;
37
38 GET_FLOAT_WORD(hx, x);
39 ix = hx & 0x7fffffff;
40
41 if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
42 if (ix < 0x39800000) { /* |x| < 2**-12 */
43 if ((int)x == 0) {
44 *sn = x; /* x with inexact if x != 0 */
45 *cs = 1;
46 return;
47 }
48 }
49 __kernel_sincosdf(x, sn, cs);
50 return;
51 }
52
53 if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
54 if (ix <= 0x4016cbe3) { /* |x| ~<= 3pi/4 */
55 if (hx > 0) {
56 __kernel_sincosdf(x - p1pio2, cs, sn);
57 *cs = -*cs;
58 } else {
59 __kernel_sincosdf(x + p1pio2, cs, sn);
60 *sn = -*sn;
61 }
62 } else {
63 if (hx > 0)
64 __kernel_sincosdf(x - p2pio2, sn, cs);
65 else
66 __kernel_sincosdf(x + p2pio2, sn, cs);
67 *sn = -*sn;
68 *cs = -*cs;
69 }
70 return;
71 }
72
73 if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
74 if (ix <= 0x40afeddf) { /* |x| ~<= 7*pi/4 */
75 if (hx > 0) {
76 __kernel_sincosdf(x - p3pio2, cs, sn);
77 *sn = -*sn;
78 } else {
79 __kernel_sincosdf(x + p3pio2, cs, sn);
80 *cs = -*cs;
81 }
82 } else {
83 if (hx > 0)
84 __kernel_sincosdf(x - p4pio2, sn, cs);
85 else
86 __kernel_sincosdf(x + p4pio2, sn, cs);
87 }
88 return;
89 }
90
91 /* If x = Inf or NaN, then sin(x) = NaN and cos(x) = NaN. */
92 if (ix >= 0x7f800000) {
93 *sn = x - x;
94 *cs = x - x;
95 return;
96 }
97
98 /* Argument reduction. */
99 n = __ieee754_rem_pio2f(x, y);
100 s = __kernel_sinf(y[0], y[1], 1);
101 c = __kernel_cosf(y[0], y[1]);
102
103 switch(n & 3) {
104 case 0:
105 *sn = s;
106 *cs = c;
107 break;
108 case 1:
109 *sn = c;
110 *cs = -s;
111 break;
112 case 2:
113 *sn = -s;
114 *cs = -c;
115 break;
116 default:
117 *sn = -c;
118 *cs = s;
119 }
120 }
121