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#ifndef lint
18static char rcsid[] = "$FreeBSD: head/lib/msun/src/s_cosf.c 152949 2005-11-30 06:47:18Z bde $";
19#endif
20
21#include "math.h"
22#define INLINE_KERNEL_COSDF
23#define INLINE_KERNEL_SINDF
24#include "math_private.h"
25#include "k_cosf.c"
26#include "k_sinf.c"
27
28/* Small multiples of pi/2 rounded to double precision. */
29static const double
30c1pio2 = 1*M_PI_2, /* 0x3FF921FB, 0x54442D18 */
31c2pio2 = 2*M_PI_2, /* 0x400921FB, 0x54442D18 */
32c3pio2 = 3*M_PI_2, /* 0x4012D97C, 0x7F3321D2 */
33c4pio2 = 4*M_PI_2; /* 0x401921FB, 0x54442D18 */
34
35float
36cosf(float x)
37{
38 float y[2];
39 int32_t n, hx, ix;
40
41 GET_FLOAT_WORD(hx,x);
42 ix = hx & 0x7fffffff;
43
44 if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
45 if(ix<0x39800000) /* |x| < 2**-12 */
46 if(((int)x)==0) return 1.0; /* 1 with inexact if x != 0 */
47 return __kernel_cosdf(x);
48 }
49 if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
50 if(ix>0x4016cbe3) /* |x| ~> 3*pi/4 */
51 return -__kernel_cosdf(x + (hx > 0 ? -c2pio2 : c2pio2));
52 else {
53 if(hx>0)
54 return __kernel_sindf(c1pio2 - x);
55 else
56 return __kernel_sindf(x + c1pio2);
57 }
58 }
59 if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
60 if(ix>0x40afeddf) /* |x| ~> 7*pi/4 */
61 return __kernel_cosdf(x + (hx > 0 ? -c4pio2 : c4pio2));
62 else {
63 if(hx>0)
64 return __kernel_sindf(x - c3pio2);
65 else
66 return __kernel_sindf(-c3pio2 - x);
67 }
68 }
69
70 /* cos(Inf or NaN) is NaN */
71 else if (ix>=0x7f800000) return x-x;
72
73 /* general argument reduction needed */
74 else {
75 n = __ieee754_rem_pio2f(x,y);
76 switch(n&3) {
77 case 0: return __kernel_cosdf((double)y[0]+y[1]);
78 case 1: return __kernel_sindf(-(double)y[0]-y[1]);
79 case 2: return -__kernel_cosdf((double)y[0]+y[1]);
80 default:
81 return __kernel_sindf((double)y[0]+y[1]);
82 }
83 }
84}