1 /* s_cosf.c -- float version of s_cos.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 * Optimized by Bruce D. Evans.
4 */
5
6 /*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17 #include <sys/cdefs.h>
18 __FBSDID("$FreeBSD$");
19
20 #include <float.h>
21
22 #include "math.h"
23 #define INLINE_KERNEL_COSDF
24 #define INLINE_KERNEL_SINDF
25 #define INLINE_REM_PIO2F
26 #include "math_private.h"
27 #include "e_rem_pio2f.c"
28 #include "k_cosf.c"
29 #include "k_sinf.c"
30
31 /* Small multiples of pi/2 rounded to double precision. */
32 static const double
33 c1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
34 c2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
35 c3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
36 c4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
37
38 float
cosf(float x)39 cosf(float x)
40 {
41 double y;
42 int32_t n, hx, ix;
43
44 GET_FLOAT_WORD(hx,x);
45 ix = hx & 0x7fffffff;
46
47 if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
48 if (ix<0x39800000) /* |x| < 2**-12 */
49 if (((int)x)==0) return 1.0; /* 1 with inexact if x != 0 */
50 return __kernel_cosdf(x);
51 }
52 if (ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
53 if (ix>0x4016cbe3) /* |x| ~> 3*pi/4 */
54 return -__kernel_cosdf(x + (hx > 0 ? -c2pio2 : c2pio2));
55 else {
56 if (hx>0)
57 return __kernel_sindf(c1pio2 - x);
58 else
59 return __kernel_sindf(x + c1pio2);
60 }
61 }
62 if (ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
63 if (ix>0x40afeddf) /* |x| ~> 7*pi/4 */
64 return __kernel_cosdf(x + (hx > 0 ? -c4pio2 : c4pio2));
65 else {
66 if (hx>0)
67 return __kernel_sindf(x - c3pio2);
68 else
69 return __kernel_sindf(-c3pio2 - x);
70 }
71 }
72
73 /* cos(Inf or NaN) is NaN */
74 else if (ix>=0x7f800000) return x-x;
75
76 /* general argument reduction needed */
77 else {
78 n = __ieee754_rem_pio2f(x,&y);
79 switch (n&3) {
80 case 0:
81 return __kernel_cosdf(y);
82 case 1:
83 return __kernel_sindf(-y);
84 case 2:
85 return -__kernel_cosdf(y);
86 default:
87 return __kernel_sindf(y);
88 }
89 }
90 }
91